Last updated Feb 28, 2023
Solensia is an injectable medication that’s FDA-approved for use in cats to bring relief from arthritis pain. In this article, you’ll learn what Solensia is, how it works, potential side effects, and frequently asked questions.
Solensia for Cats Overview
About Solensia for Cats
The brand name for frunevetmab, Solensia is a drug used to help cats with osteoarthritis.
Solensia is a brand name for frunevetmab, manufactured by Zoetis. Frunevetmab is a felinized immunoglobulin monoclonal antibody.
An antibody is a protein created by the immune system to target a particular substance. Usually, we think about antibodies against something like a virus, which helps the body avoid or quickly eliminate a viral infection.
A monoclonal antibody is a synthetic antibody that is designed to target only one specific substance. Felinized simply means that the monoclonal antibody is designed to work specifically in a cat’s body and cannot be used in other animal species.
As a monoclonal antibody, Solensia’s target substance is something called nerve growth factor (NGF). In adult animals, NGF is elevated in response to injury, disease, and noxious stimuli and contributes to neurogenic inflammation and increased perception of pain.
NGF has been found in both humans and other animal species to be involved with types of chronic pain, such as that caused by osteoarthritis (OA), where NGF has been found to be elevated in arthritic joints.
Frunevetmab works by binding to NGF, thereby preventing NGF from binding to other receptors that are involved with furthering signals of pain and inflammation.
Solensia is FDA-approved for use in cats specifically for the treatment of pain associated with feline osteoarthritis. It is available only as an injection that is given under the skin at a veterinary clinic once a month.
Also Read: Arthritis In Cats: Causes, Symptoms, & Treatment
What Does Solensia Do for Cats?
By binding to nerve growth factor (NGF) and preventing it from binding to receptors involved in the pain response, Solensia helps to keep your cat from experiencing the pain associated with osteoarthritis.
In recent years, it has become more apparent through research studies that osteoarthritis (OA) is more common in cats than previously thought. Studies have shown that although cats may have x-ray evidence of arthritis, far fewer of those cats show obvious signs of pain and decreased mobility at home. This can make arthritis in cats difficult to appreciate at home, or diagnose during veterinary visits.
But the treatment of arthritis is also challenging for cats and their caretakers. No non-steroidal anti-inflammatory (NSAID) medication is approved for safe long-term use in cats, and the use of steroids has fallen out of favor given the association between long-term use and a higher risk of side effects.
Pain medications, like gabapentin or buprenorphine, may often be considered. But while they can reduce pain and help with comfort, they do not target the underlying joint inflammation causing the pain.
Orally medicating cats can also be challenging, so even in cases where a pain medication, such as gabapentin, can be used long-term to manage pain, the high affinity for many cats to sniff out medication hidden in food or treats as well as the difficulty of pilling/medicating directly by mouth can lead to major consistency problems with treatment at home.
Solensia provides a potential solution to many of these concerns with a focused drug that appears to be very well tolerated for longer-term use, even in older cats, as well as eliminating the oral route entirely since the injection must be given at the vet’s office.
According to early studies, a single Solensia injection provided significant pain relief as evidenced by increased activity for up to 6 weeks in cats with degenerative joint disease (DJD). Based on owner assessments alone, about ¾ of cats receiving 3 doses of Solensia were considered to be treatment successes.
While still a newer product as of the time of this writing, Solensia appears to be the first drug of its kind that can be tolerated by cats for long-term use for joint pain and inflammation with the added bonus of eliminating the stress and compliance issues of medicating at home.
Also Read: 12 Warning Signs Your Cat Is In Pain And Crying For Help
Side Effects of Solensia for Cats
Several side effects have been reported for Solensia for cats.
Solensia has not been evaluated in cats less than 7 months of age or weighing less than 5.5 lb (2.5kg).
In cats, gastrointestinal signs appear to be the most commonly reported, though still relatively uncommon. According to the manufacturer, in a field trial involving nearly 200 cats over the course of about 3-4 months, vomiting was the most often reported at 13%. Diarrhea and loss of appetite were the next most common, at about 6.5%.
Injection site discomfort was noted in about 11% of cats. This was further explained to be seen as flinching noted occasionally, and most frequently with the first dose.
Local reactions at the injection site were reported in about 3-6% of cats. These reactions included scabbing, red skin, hair loss, swelling at the site, and itching/scratching.
Abnormal behavior was noted in about 6.5% of cats. This was clarified to be behavior recorded as being abnormal for the individual cat (about 12 of them in the study) but not any kind of recognized disorder.
Early studies for Solensia appear to largely demonstrate safety for cats in terms of kidney function, including cats with early-stage IRIS 1 or 2 of chronic kidney disease, though a small number of cats did have some mild changes in kidney lab parameters.
Twelve of the cats in the study showed evidence on lab work of worsening of existing mild kidney disease. In a separate safety study looking at Solensia use in a small group of very young cats, bloodwork creatinine values were seen to increase within the normal range, but never exceeded the upper limit of normal.
In a pilot clinical study published in Frontiers in Veterinary Science in 2021 titled “Efficacy and Safety of an Anti-nerve Growth Factor Antibody (Frunevetmab) for the Treatment of Degenerative Joint Disease-Associated Chronic Pain in Cats: A Multisite Pilot Field Study”, Solensia was used in 126 client-owned cats with a mean age of 12-13 years. The authors indicated that about half of the cats in the study, just given their age, were in stage II of chronic kidney disease.
Of those cats in the study receiving Solensia injections, two had elevations in lab work parameters while still staying at the same level of kidney disease, with one cat increasing to stage 3 of kidney disease.
Other side effects mentioned by the manufacturer were seen in about 4% or less of cats.
As of this writing, Solensia has not been studied in combination with other medications, including NSAIDs.
Solensia should not be used in pregnant or lactating queens.
If you are ever concerned that your kitty may have developed side effects following a Solensia injection, make sure to contact your veterinarian, the ASPCA Animal Poison Control Center (1-888-426-4435), or Pet Poison Helpline (1-855-764-7661) immediately for further advice.
The use of monoclonal antibodies is relatively new within the last several years but shows much promise in both human and animal medicine. However, a phenomenon called immunogenicity has been seen. Immunogenicity occurs when a patient’s body develops its own antibodies to the monoclonal antibody drug, thereby making the drug less effective over time.
In a study mentioned by the manufacturer, immunogenicity was detected in only 4 cats out of about 260 total cats.
Also Read: The Best Homemade Cat Food Recipes For Kidney Disease
Solensia for Cats Dosage
Solensia must be administered by a veterinarian or a trained veterinary staff member under a vet’s supervision.
Solensia is FDA-approved for use in cats, but can only be administered legally by a veterinarian or a trained veterinary staff member under the supervision of a DVM.
Dosing of Solensia is based on weight and is injected subcutaneously under the skin once a month. Each 1ml vial of Solensia contains 7 mg of frunevetmab. Cats weighing 5.5 to 15.4 lb (2.5-7 kg) receive one vial with cats exceeding 15.5 lb receiving two vials.
Following an initial dose, Solensia is designed to be continued as a monthly injection.
Also Read: What Can You Give A Cat For Pain? 6 Vet-Recommended Options
Conclusion
A relatively new medication at the time of this writing, Solensia is approved for use in cats to help ease pain and inflammation in cats with osteoarthritis.
Solensia is an injectable medication approved for use in cats to treat osteoarthritis. It provides the only current longer-term treatment option for cats that can address both pain and components of inflammation arthritis causes.
The long-acting injection also eliminates the need for oral dosing, which can be difficult for many kitties and their caretakers. Though it is still relatively new, early pilot field and safety studies suggest Solensia has a favorable safety profile.
Also Read: Drug Poisoning In Cats: Causes, Symptoms, & Treatment
Drug Dosing Disclaimer: We are only able to provide doses for medications that are FDA approved for use in cats and only as the label guidelines dictate. For medications that are used off-label we can only provide guidelines and safety information for use. Safe and appropriate dosing for off-label medications can only be determined by a primary care veterinarian.
We encourage you to work with your veterinarian to determine if a particular medication is appropriate for your cat. Changing or adjusting a dose for your cat on your own without consulting with a veterinarian can carry risk. We do not encourage use of medications prescribed for human use in pets without first consulting with a primary care veterinarian.
Frequently Asked Questions
How Long Does It Take Solensia to Work in Cats?
The pain relieving effects of Solensia have been described by cat owners in studies to be apparent after about 2-3 weeks after administration. This would be expected after the first, initial dose. If Solensia is continued long term, consistent pain relief would be expected.
Is Solensia Available Yet for Cats?
Yes. The FDA gave approval of Solensia on January 13, 2022 and is currently available for use in cats. However, since it is a relatively new drug, not all veterinary practices may currently carry it yet.
How is Solensia Administered to Cats?
Solensia is administered to cats as a subcutaneous injection under the skin. It is only approved for administration by, or under the direct supervision of, a licensed veterinarian and is administered to a cat during the course of a veterinary visit.
Is Solensia an Anti-inflammatory?
Solensia (frunevetmab) is not an anti-inflammatory in the traditional sense, as it is not a steroid or a non-steroidal anti-inflammatory drug (NSAID). However, its action as a monoclonal antibody (mAb) does have some anti-inflammatory effect.
The target of frunevetmab for treating feline osteoarthritis (OA) is felinized nerve-growth factor (NGF). In adult cats, NGF is not only involved with the body’s perception of pain and noxious stimuli, but it also assists in the release and perpetuation of certain inflammatory mediators that further inflammation in the body. When frunevetmab as a monoclonal antibody binds to NGF, it not only reduces the sensation of cat OA pain but also interferes with the continuation of inflammation that NGF contributes to.
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Plumb DC. Solensia. Plumb’s Veterinary Drugs. https://app.plumbs.com/drug-monograph/63pFWDHM97szCqfCZvcAKh. Updated July 2022. Accessed January 2023.
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SOLENSIA - Frunevetmab Injection [US Product Label for Cats]. Zoetis Inc.; 2022.
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Gruen ME, Myers JAE, Lascelles BDX. Efficacy and Safety of an Anti-nerve Growth Factor Antibody (Frunevetmab) for the Treatment of Degenerative Joint Disease-Associated Chronic Pain in Cats: A Multisite Pilot Field Study. Front Vet Sci (2021)8:610028. doi: https://doi.org/10.3389/fvets.2021.610028
My cat is getting daily prednisolone for intestinal lymphoma and is taking monthly Solensia injections for OA. Is one cancelling out the effectiveness of the other? Ok for them to be used simultaneously?
Hi Barb, thanks for your questions. Solensia is relatively very new and has not been studied widely in combination with other medications but there is no currently known contraindication for Solensia to be used with steroids. There is at least, nothing listed per the manufacturer and nothing in the drug formularies so far.
As a monoclonal antibody, Solensia targets only that specific feline anti-nerve growth factor mentioned in the article. It is not at all like or related to, a steroid.
While certain doses of a steroid can suppress the immune system, this does not, to my knowledge, impact monoclonal antibodies given as an outside medication, since they don’t rely on the body’s immune system to be produced. Also, cats being treated for lymphoma are typically not on a dose of prednisolone high enough to suppress the immune system. I hope that info is helpful. Best of luck to you and your kitty.
Thank you. That answered my question. Appreciate your quick response. I’m sure that Samson (my cat) appreciates it too! 🙂
Hi
My 13 year old got solencia about 10 month ago, she weighed nearly 24 lb very big cat. She only got one.
shot. She showed first improvement after about a week.
And lost about 11 lb in that time. She is eating the same amounts and is very active more like when she was a kitten. Eating and drinking and started bringing presents into the house again. She wasn’t able to catch anything for the last 4 years. I am amazed and wondering if anybody else had some experiences with weightloss in their cats after only 1 shot.
Hi Irmela,
I’m very glad to hear that your cat appears to be doing very well and is more active. However, I am having some trouble making sense of 11lb of weight loss in one week, especially being related to a single Solensia injection. Usually, that much weight loss in a cat that quickly would be very concerning. Perhaps there was a weight miscalculation somewhere?
Over time, decreased arthritic pain could lead to better mobility and possibly weight loss, especially if your kitty goes outdoors, but I would expect that process to take a few months.
It’s also interesting that your cat received only one injection but continues to be very active. Perhaps if there was a healthy weight loss this would reduce arthritis pain. But again, usually this is an effect over several months of time.
I would be careful to make sure weight loss has not continued to occur. Even if no, just to be sure, it may not be a bad idea to have an exam and some basic lab work done with your vet if this hasn’t been done since the injection and subsequent weight loss.
Sorry for the misunderstanding, she lost 11 lb over the course of 10 month.
Thanks Irmela, that makes a little more sense. It’s still a significant amount of weight for a cat to lose in that period of time. But I do hope that weight loss is a positive thing you’re seeing.
My cat has been taking the injection for about a year. It has been a life changer for him. However, he has developed diarrhea the last month or so. He did have pneumonia a couple months ago and was given Pred and Doxycycline. His stools firmed up to normal. Once off both meds and cured of the Pneumonia he received his next dose of Solensia. The following day he started having diarrhea. My vet has now changed his food trying to firm things up. So far nothing has made great changes. He is going in the box about 5 times a day with very soft stools. What is my next option. He is due for his next shot in 2 weeks.
Hi Lisa,
It’s hard to say why you might be seeing diarrhea after the most recent Solensia injection when you had not seen those concerns before. It’s possible some cats may start to develop some side effects with long-term use, but we don’t have a good deal of data to go off of yet. Probiotics and fiber supplementation may be helpful, as they can be continued long term if needed. Proviable, Fortiflora, and Visbiome are the probiotics recommended in my office most often. Your vet may have their own preference. Although the time association is very close, it may also be helpful to check on other causes, like fecal parasites and inflammatory bowel disease, which we would typically investigate for diarrhea that’s not improving with basic efforts.
Thanks. Heis on Fortiflora and my vet changed his food to Biome after we tried Pred and Doxycycline to no avail. He had his stool checked for parasites and was found to be clean.
my cat just received his first injection of Solensia Friday March 24th after a complete physical check up at his vet office . I have noticed now that he is not eating or drinking as much as normal . Urinating once a day size of a tennis ball amount though ! Hiding a bit more than normal .
is this a reaction from the medicine or should i be concerned ?
Hi Karen, thanks for your question. It is certainly possible that a decrease in appetite could be related to Solensia, as this has been described in a small percentage of cats (about 6%). The decrease in water intake has not been specifically noted, but that could be seen with reduced appetite or mild lethargy. Change in behavior has been noted in some cats, though nothing specific. This could include hiding behavior. Cat’s may show this behavior if they’re not feeling well. It’s also important for context to consider the reason Solensia was used and if there is any possibility that condition or another concurrent condition could also be responsible. Worsening pain for example, could also contribute to signs like these too. It would be best to let your vet know, so they can work through those possibilities. But I hope, if these are side effects, that they will be transient and your kitty will be feeling better soon.
Our cat 12 y/o just had his second shot Friday morning. He came home and drank a lot of water. He went nearly 4 days without eating and has been throwing up when we put a bowl of food in front of him. Today was the first day he has eaten anything. Can we assume that the side effects are short lived? He didn’t have these side effects after the first shot.
Hi Laura,
While the water drinking has not specifically been noted, the digestive upset signs have been reported in up to about 14% of cats receiving a solensia injection. Could certainly be related if there is nothing else possible that might have contributed around the same time. I can’t comment on why this might have been seen after the second injection but not the first. The side effects do appear to be short-lived, occurring only around the time of the injection. Because this is a newer drug, it would be valuable to let your veterinary office know that these effects occurred around the time of the injection so that they can record these occurrences in your kitty’s medical file.
My cat just got her first injection of Solensia yesterday and after she got it she seems a bit distant. I was giving her Buprenorphine for approximately 8 months now and that seemed to work great. She was wide eyed and wanted to play every morning. I’m worried about her looking like she is feeling down after her injections yesterday. Her eyes keep closing, but she is eating pretty good. I thought the injection was going to make her like a kitten again, but now I am not sure. I know it is very soon, but I am worried about her. I am chalking it all up to her being scared at the vet’s office. I gave her Gabapentin 2 hours before her vet appointment because she gets so nervous at these vet appointments. She is 15 & all other blood work came out great but she is riddled with Arthritis! She is eating okay so I am going to wait for a few days to see if it is from her being scared at the vet. I gave her a low dose of her Buprenorphine. She loves that stuff. I know it isn’t good for her, but she sleeps from it for a while and then plays a lot especially in the mornings when she was just taking that with no injection of Solensia. She keeps shutting her eyes a lot after the shot of Solensia she got. I am so scared I did the wrong thing! Her little brother died of FIP when I first got them both & he was only about 4 months old. They said they think she was carrying it, but since she is 15 now as of 5 Mar, vets say they are pretty sure she is not carrying FIP. I remember her little brother closing his eyes like that when he had FIP for those short 7 wks when I first adopted them. I am just very scared. Do you have any info you think might be helpful?
Hi Sue,
Lethargy can be seen for a lot of reasons. Stress following a veterinary visit can certainly affect a cat’s behavior for sometimes 2-3 days.
According to the manufacturer, lethargy has been reported in about 6% of cats receiving a Solensia injection. As long as your kitty is still able to go about her normal functions like eating and using the litter box, the hope is that a mild lethargy may pass within 24 hours. If you feel this is persistent beyond that time frame, or if she is not engaging in her core functions, I would touch base with your vet. Because Solensia’s beneficial effects can last for a month, an initial lethargy the day after the injection with no other issues may be a mild side effect worth seeing if you see great results the remainder of the month.
Keep in mind that Solensia is not like the pain medications you have used, like buprenorphine, where the effects are almost immediate. Especially after the first injection it may take anywhere from 3-7 days for a cat to show signs of improvement. However, pain relief will be better maintained if injections are continued monthly.
So hopefully, the lethargy passes soon and you start to see benefits within the next week. If this is the first time your cat has received Solensia, feedback for your vet would be very valuable since it is a newer treatment.
Sorry to interfere on this conversation, but can you tell me how your fur baby is doing now?
Dr Chris , thank you very much for your reply I did contact my vet and explain the symptoms I amseeing . She advised that as long as he is eating and drinking some daily not to be alarmed as it does take a week or two for the solensia to start working . I will continue to monitor him for now and hope that the Solensia does work well for his arthritis so we can continue .
Dr Chris , My cat , who is 15yrs of age has been experiencing dehydration symptoms in the past few weeks and appitite has changed . he has just received intervenus fluids and I am wondering if the Solensia can be a contributor to the reason why all of a sudden he is experiencing dehydrations symptoms and possibly stop the treatment in case it is a side effect of the solensia. Hoping you can give me your thoughts on this issue.
Hi Karen,
Dehydration usually occurs secondary to some other process and is not really a side effect in and of itself. GI signs, like vomiting, diarrhea, and anorexia, which can cause dehydration, were seen in up to 14% of cats during a clinical trial for Solensia. However, these signs occurred at a similar frequency to cats receiving a placebo as well.
If your cat is not eating as well, that could be a cause of dehydration. In older kitties, other illnesses can occur at the same time that can contribute to what you’re seeing. Lab work can be helpful to assess the function of the kidneys and other organs to see if there are any contributions there to the appetite decrease.
With any drug, our goal is to balance benefits with side effects. If you feel your cat is benefiting from Solensia in terms of arthritis pain, and any side effects can be managed, you can consider continuing. If there is concern potential side effects may be causing more issues than benefits Solensia is providing, you can speak with your vet about other options to manage your kitty’s joint pain.
Karen i just took my cat in with same dehydration, low temp, needed iv and oxygen im wondering to if this a reaction to solensia injection my guy has one had 2 shots and the reaction is more this time than the first time.
The worst part is my cat hates car rides so I have had to reschedule his Solensia visits often (increased mobility means better hiding). Is there any chance this could be adminitered by the owners? (we’ve done sub-cut injections before). Thanks!
Hi April,
Solensia is a very new medication, and so my impression is that in order to standardize better for monitoring of side effects, injection site reactions, etc., it is currently only being given by a licensed veterinarian or under their direct supervision. This is not to say that this may not be relaxed at some point, especially for cats who are stressed or difficult to handle in the hospital but who may be easier to handle at home. But this would be up to each individual veterinarian’s comfort level as well as the pet parent’s.
Hi April, I have heard of Solensia being administered at home; I think you’ll need to talk to your veterinarian about it! Wishing you all the best.
Is Solensia ok to
Use in a cat with a moderate heart murmur?
Hi Sands,
To my knowledge, there are no contraindications for using Solensia in pets with heart disease, assuming the condition is stable.
Hello Dr. My name is Gary VanHorn. I live in Phoenix, AZ. I called my vet to see about buying SOLENCIA for my cat but was told they never heard that medication. So, my question is where can I purchase this medication, preferably in person or, at least, online? Thanks Dr.
Hi Gary, thanks for your question. Unfortunately, since Solensia is an injectible medication that can only be given under direction of a veterinarian, it cannot be purchased online to my knowledge. It is most often given in the veterinary clinic by a veterinarian or veterinary team member. Some veterinarians may be comfortable providing a dose and a syringe so an owner can administer it at home, but that would be the only way to get it for home use. Like many other injectible medications we use in the hospital, it can only be ordered through a medical supplier. I know that may be frustrating, but it is still considered a newer drug on the market. My own practice has only had it for maybe six months, so hopefully your veterinary office may carry it in the near future, especially after your inquiry. There’s likely another veterinary practice in your area that carries it, but you’d also likely need an exam first for a new vet to assess if Solensia is an appropriate option for your cat.
Thx Dr.
Gary, I live in Phoenix and my cat’s Vet suggested this for my cat. You may need to call a few Vet offices as some know about it and do administer the medication.
Quick note : Your Solensia article (paraphrased) says there are no approved NSAID arthritis medications for cats, but your Robenacoxid article contradicts that.
Hi, thanks for your comment. While Robenacoxib is an NSAID medication, it is only FDA approved/labeled for use in cats for up to 3 days and only for inflammation associated with soft tissue surgery, like a spay or neuter. It does not carry a label for longterm use or for use for arthritis. While some may consider using it off-label for longer periods, cats are very sensitive to NSAID medications, and most veterinarians are very reluctant to use Onsior for any further length of time. This makes it a less than ideal choice for arthritis where a medication must be given longterm. By contrast, Solensia is the first approved medication specifically for long-term management of arthritis in cats. I hope that provides good clarification.
My 16 year old cat had her first injection. The first week she was fine, but the second week she lost her appetite and loose stools and hunched up again. Are these side effects and short lived? Maybe the 2nd injection will be better?
Thanks
Hello Gale, thanks for the message. I would talk with your vet to get more clarity on the situation, but side effects of Solensia can sometimes be long-lasting, not going away until up to 4 weeks after the last injection. It’s curious that it started a week after the first injection, so I would talk with your vet for more clarity. Wishing you all the best.
Hi Dr. My name is Lynda N. My kitty is 16 and on 6th shot of solensia. It has helped with her mobility, but she has had a sore by her head,eye neck area
.she scratches it bad been to vet 5x antibiotics and prednisone not completely healing it? Could it possibly be the Solensia. Thankyou so much
Hello there! Dr. Vanderhoof is unavailable to respond to comments right now, so I’ll jump in and say that the most common side effects of Solensia are skin reactions, so that does seem to suggest that it may be a reaction to the medication. I would talk to your vet about it further.
Hi , my cat Olga is 16 and she started with Solensia in December 2022 after a very bad arthritis. I was very impressed with her reaction to the first shot. After 3 days she looked completely healed and she was walking with an ease. Sometimes in January 2023 I noticed huge scratches on her neck, shoulder and ear. Her vet was questioning if Solensia was a reason for that but she got a bit better. I have been watching her from the day she gets the injection and her reactions- she was going well for almost three weeks after , sometimes she vomits in a first week ,but the forth week was a disaster. She starts scratching and extensively leaking herself, vomiting mostly hairballs and some food too. The good thing is that she eats well and I also noticed that she has been drinking more water than before Last three days she was hiding in the basement as she was due today for the next shot- her biological clock tells her that, I guess.. Leaking and scratching is so loud that I cannot sleep. My vet is going to take some time to study this new medication and its side effects and other possibilities for Olga. She had never had any issues with her skin before Solensia. I am so sad because she is moving way better now . I just though that would be useful for the others to share our experience and ask Dr. Vanderhoof for his opinion and how to help Olga to get better . I see that other cats have problem to heal after all. Thank you very much!
Hi Spomenka,
Thanks for sharing what you’ve been seeing with your kitty. What you’re describing in terms of generalized itching and scratching is not one of the more commonly reported side effects, but the drug insert does show that during clinical trials, dermatitis (skin inflammation) was seen in about 6% of cats while itching was seen in about 4%, so it does occur.
It’s very likely that these signs are reversible if Solensia is discontinued. I know this would be unfortunate since it appears to be helping your kitty’s arthritis pain. But if these side effects are causing more issue than the benefits you’re seeing with Solensia, that may be what you have to consider.
A steroid may help with the itching, but that may not be a viable long-term strategy as steroids have their own long-term side effects to consider.
There are other strategies you can chat with your vet about for approaches to managing arthritis pain if Solensia ends up not being a good treatment choice.
My 17 year old male cat (hyperthyroidism medicated and under control, early stage renal failure with kidney diet and sub Q fluid replacement) has received 6 monthly doses of solensia. While overall we think it has helped his ability to walk with extremely arthritic legs and hips (he is a stub tail), we notice increasing inability to walk, use his hips, and falling over for a week following the injection every month. After that week passes, he is walking better and jumping on furniture. We are ok another 3 weeks until the next injection when we go through it all again.
It seems this pattern has worsened over the last 2 months injections. After the July 2023 injection last week, it seems he cannot use his right leg when he was using it fairly well before the injection. the injection was not in his right hip. Since this occurs every month after the injection, we think this is a side effect. His desire to eat and interact is also negatively affected for the week after the injection. It now seems to us the consequences of the week following the injection is not worth the benefit. We would be very very concerned with the behavior we are seeing if we had not been through the terrible week following the injection in the past. Any thoughts on this? We are ready to quit the Solensia.
Hi Deborah,
In the field study for solensia, there are numerous side effects that were observed, though the highest percentage of cats experiencing side effects was only about 13%. Only two side effects, vomiting and injection site pain, had double digit percentages of occurrence. All others occurred in less than 10% of the nearly 200 cats in the field study.
Anorexia (poor appetite), lethargy, and lameness (limping) were seen at about 6.5%, 6%, and 4% respectively. Because injection site pain is listed separately, I am assuming that the lameness is more what you are describing with limping not occurring near where the injection was given.
Here is a link to the medication insert through Zoetis’ website, which allows a full view of all side effects that were seen and how common they were.
I can talk all day about how uncommon the side effects you’re describing have been with solensia in a majority of cats, but the reality is any rare side effect matters quite a lot if it happens to your cat.
Our choices with any medication have to be a balance between benefits and side effects and it is reasonable to reconsider a medication if the balance shifts towards seeing more side effects than benefit.
Since solensia is still a very new medication, it can also be worth having this information reported to Zoetis.
How long does it take for the lameness side effect to resolve?
It appears the lameness side effect is rare. I have not seen it in any of my own patients and I don’t believe the colleagues I work with have either. Zoetis does gather data on side effects when they are reported. That would be the best source to find out how frequent the side effect is and how long it has been seen for. Your vet’s office may be able to contact them to report this occurrence. At best though, one would hope it wouldn’t last more than a couple days after the injection.
Hello Dr. , Our 14 yr old male cat has been getting Solensia injections for at least 6 mos. Approximately 2years ago , he had to have an amputation of his left rear leg due to a fence injury. He had already been having issues with his right rear leg, diagnosed by our vet as “mice” on that knee. With the loss of his healthier leg, the strain on the right leg resulted in the starting of the Solensia injections.
His reaction to the treatments had been nothing but positive, until the last 2-3 weeks. He’s been more affectionate and playful than we can recall, but we are now concerned that the continued stress of only having the one arthritic leg has overshadowed the effects of the treatment. He has been almost dragging the rear leg recently and we have also noticed weight loss, we assumed due to age. Our vet unfortunately came down with Covid last week and we had to reschedule his visit til this coming week. He’s a handful to get into the carrier, and like many cats, hides quite well when he knows its time to go. He de-stresses fairly well, though.
I guess my question is, has enough research been done to determine how long he will be able to function well with this treatment, especially with the added strain of having only one leg and his age. Thank you for your response.
Hi Mary,
Thank you for sharing about your special kitty. The longest evaluation for Solensia for clinical trials was about 3 months or 3 injections. It’s still a very new drug, so I would expect when it has been out longer that we may see some prospective studies published where they follow progress in cats who have been getting injections for several months or a couple years.
Arthritis is always progressive. Extra weight and stress on a more arthritic leg just on its own could contribute to it progressing faster. The goal of any anti-inflammatory or pain medication we use for arthritis in pets is to slow down the process but we can’t stop it. At some point it may outpace any medical therapy.
I don’t know if this for sure has happened for your cat, but it could be possible from what you describe. Dragging a hind leg could also be from causes other than arthritis. Weight loss can have many causes. Your vet may be able to narrow things down with an exam and diagnostic testing. Hopefully they feel better soon and you’ll be able to get a better idea of what’s going on.
Thank you for your reply. We got “Amos” his shot, he seems to feel somewhat better, but he’s just struggling more in general. Good spirits, appetite, etc. Just physically struggling more. We have another appt. for him next week for an eval. of the leg. We know his age is also a huge factor here. Hopefully we can find some additional treatment that will help with this.
Again, Thanks for your info- MT Windsor
My cat got her first shot about a month ago. She did really good after the shot..no immediate side effects. Seems to move a little better. However, I have noticed since her shot that she seems to star into space more often…and display other small cognitive quirks that I never noticed before. Has any cognitive issues been reported with this drug/. Thank you.
Hi Missy, thanks for your comments and question. In one clinical study from 2021 evaluating safety of Solensia (frunevetmab) lethargy was recorded in about 2% of cats over the course of 2 months (2 injections). This is the closest thing to what you’re describing. Lethargy is somewhat generic, so perhaps it would encompass what you’re seeing. Cat owners involved in clinical studies did not specifically report any cognitive changes.
My cat Simba had Solensia shots starting in August of 2022. We also at the same time had our other cat receive a shot also. Well not too long after they both started to bellow at night. My daughter was very annoyed with the bellowing all night so we wondered if it was from Solensia. So she did it get him another shot an after awhile the bellowing stopped. But the vet said that Simba had bad hip arthritis so I continued with the shot. Well I wish I would have put two a two together. He started walking in circles. Kept going around the couch. We thought what is wrong. Still crying every night. Wouldn’t sleep hardly at all. Awake all day long. I have quite a few other cats. Let’s face it. Cats sleep a lot during the day. Not Simba. He was awake all the time. I thought it was strange. So this is after about 4 shots. He’s 14 years old. So I took him to the vet. He had high blood pressure. Now I’m wondering did the Solensia do that. He stares. He looks like he can’t see. After just his last shot 5 days ago I started thinking my gosh I am so stupid. He was eating wonderful. I take him in an now my cat is sick. Threw up 4 days now. He has diarrhea. Not sleeping. He will be crying about 4 in the morning he does it every day. He acts like he has dementia. I’m thinking my God I’m killing my cat. So now I’m praying he gets better. No solensia again. I pray he lives thru this. He’ll lay with his head tilted. Mind you he was in good health a year ago in August now I cry Simba I’m so sorry I’ve made you sick. There’s so much more I could write. I wish I would have thought of this earlier but they said oh Solensia is FDA appproved. I trusted them. My cat is sick. He cry’s doesn’t sleep throws up and did this stuff give him high blood pressure.
Thank you for sharing and I’m sorry to hear about the difficulties with your kitty Simba. Hypertension/high blood pressure is not something that has been described as a side effect of Solensia. I’m not clear how much it has been evaluated in field studies, but it also has not been reported in humans being given similar medications.
Behavioral disorders have been reported in about 13% of cats, which what you’re describing would likely fall into. Some people receiving similar medication have reported neurosensory symptom types of effects (like pins and needles feelings, reduced sensation, or increased sensation). Perhaps if a cat experiences this, it may result in altered behavior.
It does sound like over the course of the year that Simba has received the Solensia injections fairly infrequently, so I can’t say if it’s related to everything you’ve seen or not. Older cats are more often getting Solensia injections because arthritis affects them more. Unfortunately, older cats are also prone to other separate illnesses that may be occurring at the same time.
I’m not sure why it would happen just with the most recent injection as you did not mention it previously, but vomiting is one of the most commonly reported side effects, so what you’ve seen following the most recent injection could certainly be related.
Hi there, my cat was doing a lot of the same things and it was because she’d suddenly become nearly blind from high blood pressure. Her retinae were detached in spots. I don’t think Solensia caused it but could have made it worse. If your cat hasn’t had an eye exam, maybe that would help figure this out. I hope your kitty gets better soon!
Hello, my cat 16 and half year old cat got diagnosed with Lumbasacral disease last week. To manage pain, his vet suggested solensia. He has been doing well and pain seems to be managed as he is jumping, playing and walking now. Although both his back legs are still slow.
My question is, is solensia a blood thinning pain medication ? For example, aspirin for humans is a pain killer but blood thinner as well.
I’m wanting to transition him to SerraPet natural pills soon as SerraPet is a pain and anti-inflammatory medication as opposed to Solensia which is strictly a pain med but I can’t give both simultaneously if Solensia is a blood thinning med.
I can’t find any information on this question and would appreciate your answer.
Thank you !
Hi Ker,
To my knowledge, Solensia does not have blood thinning properties. This at least has not been described in the medication information by the manufacturer or any of the clinical studies. I also have not seen anything about blood thinning when reading about human monoclonal antibody therapy.
Blood-thinning in anti-inflammatories is a fairly unique property of aspirin among anti-inflammatory medications. Solensia is not a non-steroidal anti-inflammatory in the traditional sense like aspirin.
A couple things to clarify to answer other parts of your post. Solensia is not just a pain medication and actually does address inflammation. It does not block the COX-2 pathway of inflammation like many NSAIDs, but by inhibiting nerve growth factor (NGF), it helps to decrease other mediators of pain and inflammation in joints. This is why many veterinarians have been very excited to use it because it in theory addresses arthritic joints more effectively than just masking the pain, like say gabapentin.
I cannot find a great deal of reliable information on serrapeptase, but there probably are at least no contraindications to using a proteolytic enzyme with Solensia. However, it’s important to be aware that serrapeptase is not a medication. It is instead a nutritional supplement. This means it may have anti-inflammatory properties, but has not had any kind of clinical trials, testing, or FDA approval for that purpose.
Hello and thank you very much for your response.
Since Lumbasacral disease is progressive with no cure, it is essential to manage Alvin’s pain. Our vet was unable to answer how fast it will progress (understandably so as every cat is different) but I’m wondering how long we can keep him on Solensia? Years? Months?
To recap, in your medical opinion, Solensia and SerraPet have no interaction and would be safe to give together?
Alvin will also start cold laser therapy in a mid Oct (earliest appt we could get).
The reason we are considering SerraPet is the possibility that it can stall progression, give him mobility back (although Solensia has given him 90% of mobility back).
I’m considering not giving him SerraPet if he can stay on Solensia for as long as he needs in combination with cold laser therapy.
Thank you very much and I value your time and medical expertise!
Hi Kerr,
I can’t vouch for SerraPet as I am not greatly familiar with it, but there would be no contraindication that I can see with the serrapeptase. However, I would imagine that combining other therapies with cold laser therapy would make a big difference too. Especially since laser therapy helps a lot with the sore muscles in the back that can be a part of lumbosacral pain. The prevailing opinion currently is that Solensia is the best long-term therapy option we have for arthritis in cats. Zoetis has been advising continued use is safe and appropriate. The longest clinical trial lasted for 3 months (3 injections). I have mentioned in a previous post that Solensia is still very new and that there will likely be longer-term use data that will come out once the medication has been out for a couple of years.
Hi. My kitty, Haiku is 14 and has been solencia for about 6 months. She has had arthritis in her back It seemed to help for about 2 or 3 months, and then leveled off. She lost a little weight, which she needed to do. Her urine output definitely increased. By the 4th month she was getting the cat litter caked on her back legs and started having a hard time walking. She would not wake up when i opened the can of cat food. Her eyes started to look different. Long story short, the vet did blood work on her this week – somewhere between starting the Solencia and now, she has developed diabetes. I don’t know if there is a correlation or not. It’s hard to know which symptoms were the arthritis in her back, the beginning of the new medication, or the diabetes. I see that many of the previous comments include some of the symptoms my kitty has had. Have you heard of any others develop diabetes?
Hi Liz,
I’m so sorry to hear that your kitty has developed diabetes. That can always be a tough change to adapt to. It sounds like the changes you noticed were all related to diabetes, including the increased urine output, lethargy, poor appetite, etc. The weight loss can also occur secondary to diabetes and some cats will develop difficulty with their back legs due to what is called diabetic neuropathy.
You did mention that your kitty needed to lose weight, which tells me that she was likely overweight. This is really the number one risk factor for cats developing diabetes. And I have unfortunately seen the change occur in some patients over a short period of time, though sometimes the changes are slow and the disease is not recognized until it has already been present for a few weeks.
Diabetic changes have not been reported secondary to Solensia and would not make sense to me, as the medication would have to be contributing somehow to insulin resistance. Blood work rechecks were done during trials of Solensia and alterations in blood sugar were not among any changes seen.
I do think it is much more likely that the diabetic condition developed independently.
My cat was recenely diagnosed with Hyperthyroidism. her vet and I decided to try her on Silencia. She is 16 years old with arthritis. She has been throwing up, for 3 days now. Not able to eat or drink, unless she has anti vomiting medication. She wno’t eat puree, chicken breast, small cit (Her favorite) or treats. I’m scared I’ve hurt her by giving this shot to her. It all started on Sat. (Her first and now will be only shot). How long will this last? I’ve had her in the vet ER, waiting 8+ hours to be seen, tests run, Kidney and liver looked fine. It all started about 10 hours after getting this shot. Did I kill my cat?
Hi Felicia,
I’m sorry to hear your kitty is having a hard time. While I can’t be certain, the timing of the vomiting and poor appetite mean they could certainly be related to the Solensia injection. I’ve found it to be a very helpful medication, but as with any medication, side effects can always be a risk.
According to the manufacturer, vomiting was the most common side effect in a field study. Although the most common, it still only occurred in about 13% 182 cats involved in the study. Anorexia, or poor appetite, occurred less often, at about 6-7%.
In many cases, these side effects resolve after a couple days with some care and support. I hope that is the case for your kitty.
You erased my comment. I don’t understand why, because my cat is seriously having issues. If you can’t help, you should just say you can’t, but erasing without anything, is a terrible thing to do. I was just looking to see if you knew how long she would be sick for. Or if there was anything that could counteract Solencia.
Hi Felicia,
Please be assured that no one erased your comment. Please keep in mind that all blog responses must be first approved by a moderator before they will be posted. Response may also take up to 2-3 days. I did provide an answer to your original question which I hope is helpful. The blog and comments section is not intended for any urgent health questions. If you do have any questions you need an immediate answer for especially if it relates to a prescribed or administered medication, it’s best to contact your veterinary office. Local ER hospitals can also answer urgent questions after hours.
Hi Chris! Our cat Carson has received five shots of Solensia now; all about a month apart with the most recent being just last week. Prior to the Solensia shots, Carson has had issues from time to time with chewing his fur. We have tried giving cyclosporine orally for that but it has been hit or miss getting it into him. He won’t take it in his food. In the last 6 weeks or so, this problem has gotten much worse. He has chewed spots on his sides and hind legs and there is no hair on his belly now. He also has scratched spots on his head. Six weeks ago, in addition to the Solensia, the vet gave him a shot of Convenia and Depo-medrol. Last week he got the Solensia and another shot of Convenia. Is it possible the Solensia is exacerbating the problem? Any help you can give us is greatly appreciated.
Chas & Ruth
Hi Chas and Ruth, to be clear, I can’t know if Solensia is causing the worsened skin allergy type signs. But is it possible? Yes, I would say it is possible. The longest field studies were for about 3 months, so to some degree I think we have to keep an open mind with kitties who are now getting the injections beyond that clinical trial timeframe. Skin conditions were seen in only a small percentage of cats, but there’s no way to know if those cats had any skin allergy conditions prior. It’s such a new medication that we also just don’t have data on if cats with existing skin allergies would be more likely to develop such side effects. It is also of course possible that a cat with atopic dermatitis could be having a flare for a completely different reason, so I would still go through the routine of evaluating some of the routine possiblities for an allergy flare (diet change, flea allergy dermatitis, any potential new environmental allergens in the home, etc). If these seem unlikely, and if your kitty continues to have breakthrough problems you could consider discussing discontinuing the Solensia with your vet and see if things settle down. You would have to weigh this option against the benefits you’re seeing with Solensia for mobility and arthritis. We certainly don’t want to be causing more potential harm than benefit with any medication or treatment.
Hello,
I am looking for more guidance and ideas, please. Our cat is three years old and for the last 5 months, he has started urinating outside the litter box. It was once a day, then after the vet and meloxicam, it was once a week or even two weeks. We have taken him to the vet, switched his food to the Hills C/D stress, and added more litter boxes. We have a total of three cats. We started fostering them when they were 4 weeks old. There are no fighting issues and all get plenty of love, cuddles, and playtime. My cat seems to be in pain, hides more, and sits in a hunched position more. We have tried gabapentin, and meloxicam. He seemed to do better for a few days during and after the three-day dose of meloxicam. We have Feliway plugins all over. We were just at the vet again for another urinalysis and blood work. All came out well. We tried our first dose of Solensia about 8 days ago. He is urinating outside the box almost daily now. He is more lethargic, his fur is different, spends most of the day hiding under a blanket. There is something wrong with him. He is not acting like he did over 5 months ago. We are certain it is not behavior. What is wrong with my cat? Please help.
Hi Nicole,
Inappropriate urination is unfortunately very common in cats, collectively referred to as feline lower urinary tract disease (FLUTD), lower urinary tract signs (LUTS), or feline urologic syndrome (FUS). In many cats where some obvious causes like urinary tract infections or bladder stones have been ruled out, the remaining classification is feline idiopathic cystitis (FIC).
Cats with FIC can have symptoms ranging from mild to severe. Even cats with mild signs appear to have bladder discomfort and engage in inappropriate urinary behavior. This is thought to originate from some kind of internal stress that leads to changes in the bladder wall’s protective layers, allowing inflammation to occur. It is a very complex and not well understood process, but some experts describe these cats as being “poorly wired” to cope with stress.
This can occur more in multiple cat households. Even if the cats don’t fight, there may be subtle but complex social hierarchy issues occuring that are not obvious to us. Sometimes a trigger event or change can be recalled (like 5 months ago when this started) but sometimes not. Because some kind of stress is often involved, a medication for stress and anxiety can be considered to try to help with long term management if that has not been tried yet. Some approach with gabapentin as a way of providing both a calming effect as well as pain relief.
A couple extra thoughts. Long-term anti-inflammatory options in cats are generally poor (Metacam is best used only for very short-term and is risky otherwise), which is largely what has led to interest in using Solensia off-label for bladder inflammation in cats because the nerve growth factor (NGF) it targets can be found in urinary tissue. But I don’t believe there has been any formal research or publications yet for this particular application.
It’s not clear to me if you’re seeing side effects from the Solensia injection or continued issues despite its use. Solensia does not cause urinary problems as a side effect, but it may cause GI upset or injection site irritation in some cats and these may cause an FIC cat to urinate inappropriately, at least initially. I hope the effects would be temporary if they are related. Some say it may take a couple months to see the full benefits of its use for this purpose. You would have to see if there are some benefits seen in the next couple of weeks to see if it would be in your kitty’s interest to continue them.
Thank you for the information. We have compounded forms of gabapentin, the quad tab chicken flavor and the liquid oil suspension in triple fish/marshmallow. We were hoping that in one of these forms he would tolerate it better and it would be less stressful, nope. 😕
He is a member of our family and we will do whatever we can to help him feel better. At first we thought it was behavior but he was meowing and having trouble going. When we first went to the vet he had antibiotics, anti inflammatory, switched his food to the Hills C/D Stress and things were good for a several weeks. Then he started going again ( once, then again 6 days later, then 5 days later and so on.). His behavior also changed. He became less social, hunched in position, less playing. We went back to the vet and he received a three day dose of meloxicam and he started acting like himself again and no issues for over two weeks. Things started again with him going and acting like he is in pain. We went back to the vet and did urine and blood. Initially they were thinking maybe diabetic because there was some sugar in the urine but the blood test came back fine. We did the shot of Solensia and hope something starts to help him long term. We want him to feel good. We appreciate the feedback and information. The more we read and try to learn the closer we will get to helping him live his best life. 😀
Hi My 16 year old cat took his first dose of Solensia dec 2023 and his second shote Jan 15 2024 his first shot he seemed better walking more and drinking more than ive seen him. He has moments where he seems out of it. He slowed way down eating which im not to worried as he is overweight but i don’t want him to get dehydrated either. Had vet run feline senior labs on him and they were all normal. Now after the second shot he not eating for a few days he’s drinking water and peeing. hes very vocal which he never has been. He has moments of looking like he is out of it still. I noticed breathing is irregular i have taken him back on for feline viral panel and an xray. He has had a hx of cystitis. Does this Solensia mess with cats brain function since its monoclonal and goes to the pain sensor in the brain?
Hi Lori,
Sorry to hear your kitty is having a hard time. Anorexia like you’re seeing is a documented side effect that has been seen. The intermittent lethargy you’re reporting is also something that others here in the blog have reported seeing too. Solensia should not have an effect on the brain or brain function though. Monoclonal antibodies as a group do not typically cross the blood-brain barrier and Solensia does not interact directly with a pain sensor in the brain. In adult animals, the receptors for nerve growth factor (NGF) are primarily found in the periphery of the body including certain cells within joints and peripheral nerves. If NGF binds to those receptors, this signal will be perceived by the brain as pain related. Solensia binds the NGF being produced (in higher amounts with arthritis) in joints and peripheral nerves thus preventing those pain signals from ever getting to the brain and preventing additional pain and inflammation signals from being released.
Don’t overdose Solensia. I thought that my can can have it for a long time but after 8 months the side effects were severe… Then I read that Solensia safety hasn’t been evaluated beyond 6 months…
Just read lots of comments about Solensia here. My Cat (11years old) has problems with diahhrea and lack of apetite after taking Solensia. But I guess she was getting it for more then 8 months, which is not recommended. I didn’t know that, and my vet was nothing informed about it as well. Now we stopped. And after reading your comments here I decided to not give it to her anymore.
There is no kind of official information saying that continuing Solensia longterm is not recommended. However, it is very true that we have no safety or efficacy data for longterm use of many months or years. I have mentioned before here that since the medication is relatively new, longterm use data will likely be available in the next couple of years. Until then, my own approach is to first see how a patient does with it for that initial 3 months. If we’re doing well with no side effects, I try to make it clear that we’ll take it one month at a time and if any concerns develop, to get in touch as soon as possible so we can re-evaluate how to continue. Solensia has great potential to help cats with arthritis pain more effectively than any other options we have. But I agree we would all feel more comfortable with some more longterm safety and use data and until we have that, we have to keep a close eye on cats receiving injections beyond 3-6 months.
Hi Dr. Vanderhoof,
Thank you for this informative article. I have some questions that I know are hard to answer, especially given the newness of this drug, but I would love your insights anyway. I have a geriatric cat who is in pain because of a bladder tumor. As a last resort for pain control before putting her to sleep, my vet Suggested we could try to use Solencia off label. I don’t want to prolong her suffering, but I want to give her enough time to see if if the medication is working. She got the injection yesterday. How long do you think is enough time to see if it’s helping with her pain? My vet said we could give her a week and then re-evaluate. Would you agree? Again, I know this is tough question, but I would love any insights you have.
Hi Dr. Vanderhoof,
Thank you for this informative article. I have some questions that I know are hard to answer, especially given the newness of this drug, but I would love your insights anyway. I have a geriatric cat who is in pain because of a bladder tumor. As a last resort for pain control before putting her to sleep, my vet Suggested we could try to use Solencia off label. I don’t want to prolong her suffering, but I want to give her enough time to see if the medication is working. She got the injection yesterday. How long do you think is enough time to see if it’s helping with her pain? My vet said we could give her a week and then re-evaluate. Would you agree? Again, I know this is tough question, but I would love any insights you have.
Hi Katie,
I’m so sorry to hear about your kitty’s current situation. And you’re right, this is a bit of a challenging question but I’ll do my best.
Solensia certainly has been used off label to address bladder inflammation. The rationale here is that nerve growth factor (NGF) that Solensia targets, which is a mediator of pain, has been found in bladder tissue cells as well (as joints). To my knowledge, veterinarians have been using it off label more as a therapy for sterile or idiopathic cystitis in cats, especially the kitties that have recurrent stress-induced bladder inflammation. The guidance we’ve received for using it in this manner is similar for that with joint pain. We might be optimistic and see some benefits at least one week following an initial injection, but it may take up to 3 of the monthly injections to get a full impression of the benefits it may have.
I can’t speak too much on its use with bladder tumors. While it has no known effect against the tumors themselves, it may be possible that it could help with pain and inflammation associated with them. However, since tumor cells are not normal bladder cells anymore, I don’t think we really know. Bladder tumors can be responsive to NSAID medications, but these generally carry a high risk of side effects for any extended use in cats. I think your vet has made a reasonable decision to see if Solensia may help. But if signs of the tumor are worsening and noticeable change isn’t seen within a week or two, I don’t know that it would be appropriate to hold out hope for another month or longer to see a significant change if quality of life is declining.
Hi Dr. Vanderhoof,
Thank you so much for your thoughtful, thorough, and evidence based response — it was truly more than I could have hoped for. I appreciate your taking the time to consider all the complex variables in my situation and to provide informed insights into Solensia pharmacology, its off label uses, and most importantly, how these relate to my cat’s condition. The question of holding out hope versus quality of life is such a difficult and painful one, and can lead to feelings of doubt or regret, especially if big decisions are made blindly. But your guidance helps me feel much more informed, and that is all I could ask for. Thank you so very, very much.
I remember reading about this treatment in an article by PetCareRx. The benefits look pretty promising. I hope more cats find relief from arthritis through this course of treatment.
My cat who’s weight is 5#9oz. had a solensia injection two weeks ago and today she had blood in her stool. Has that happened to other cats?
Hi Darlene,
Blood in the stool specifically has not been documented with Solensia to my knowledge. However, general digestive upset signs can occur in some cats and blood in the stool may be seen with some cases of diarrhea or loose stool as part of bowel inflammation. I don’t know the likelihood of it being related two weeks after the injection was given, but it may be possible if no other causes seem likely (like a dietary indiscretion for example).
I have started my 16yr old cat on Solensia mid year last year (2023) he has gotten 4 injections.. in December 2023 he had senior blood work done.. pretty normal for a 16yr.. started him on on rx food for kidneys on the cautious side… in April 2024 his blood work was retested… absolutely horrible results.. he is now on sub fluids twice a week… ive been hearing that Solensia is causing kidney failure at an alarming rate… i am really concerned about the safety of this injection
Hi Linda,
I’m very sorry to hear you’ve seen some progression with your kitty’s kidney disease. I’ll field your concerns about as fairly as I can.
In clarifying some of your history, it sounds like your cat received a first Solensia injection almost a year ago (if it was mid 2023), but to date only received 4 injections, and was not receiving them monthly. I’m not clear if they were being given regularly every couple of months or if they were grouped together with larger gaps (such as all four given monthly through the fall and then discontinued or perhaps the first injection followed by a several month gap and then the final three given later in the year or early this year).
It sounded like there were no major concerns on lab work in December, but if a kidney diet was started, that would tell me that some degree of kidney disease was present at that time.
Now, Solensia was studied in cats with early stage kidney disease IRIS Stage I and II for up to 6mo months in safety studies. While some mild increase in creatinine was seen in some cats, the overall degree was found to be the same in the placebo group as well, that didn’t receive Solensia.
While cats can do better with kidney disease than dogs, the condition in most cats is going to progress within 1-2 years. In fact I just had a feline patient, 17 years old, who just had bloodwork done 5 months ago with perfect looking kidney function who now last week showed IRIS stage II kidney disease. He is not on Solensia (or any other medication). My point here is that what you’re describing happens quite often and was happening long before Solensia came to market.
Solensia has been out now since January of 2022 and not all veterinary practices carried it right away. Since most cats will see progression of their kidney disease in 1-2 years, I also worry that we are simply seeing some cats who have been on Solensia for that same period of time having a natural progression of their kidney disease or progression for other reasons, like a subclinical kidney infection (which occurs more often than you’d think), which is then blamed on Solensia.
Now, on the flip side, there are no studies evaluating Solensia after a 6mo period of continued use. My own practice has only carried it for maybe 8 months and we haven’t appreciated any pattern of concerns other than some cats having skin irritation. But I have heard of some unusual changes in some cats that might not have another clear explanation besides chronic, regular use of Solensia.
I think it’s definitely possible that in cats receiving the injection regularly for close to a year or longer, that we are in a bit of uncharted territory and we are perhaps seeing things like that now with the product being around for about 2 years and some practices have been using it for about 1-2 years.
Perceptions of Solensia are also complicated by the fact that it is used almost exclusively in older cats over the age of 10. These cats are inevitably going to have other concurrent diseases besides just arthritis and early stage kidney disease. I have no doubt that because cats hide illness so well that Solensia injections are being given without knowledge of some underlying disease processes that are present. Despite how much focus we put on bloodwork, it can’t tell us everything and more thorough work-ups can be cost prohibitive a lot of times, leading us to focus on trying to treat what we do know is there.
While you may have been reading that Solensia is causing kidney failure in cats at an alarming rate, this doesn’t agree with what we’re seeing in veterinary practice. At least in my own, we’re not seeing this in the 8 months we’ve been carrying it and I haven’t heard this from colleagues who work in other areas of the country either.
If you read blogs (this one not excluded) about Solensia, you’re going to find that most posts are about adverse events, which is the same for any medication. Far more people are going to post about the bad things that happen than successes, which is understandable. They are frustrated, upset, and even angry, and want to be heard.
When something occurs that we feel is an adverse event or reaction, it’s common to search extensively with that focus, leading to results that agree with our concerns. This is confirmation bias or motivated reasoning, which are both common human tendencies, especially with searching for information online.
Although it’s not impossible, I would have a hard time seeing Solensia being responsible in this case, since 4 injections falls well within the safety study parameters and the injections may have been spread out over a longer time. But if your kitty’s kidney disease has progressed to stage 3 or 4 (which I hope is not the case but I’m worried it is if fluids are needed), then Solensia should definitely be discontinued as there is no safety study information in cats with these two more advanced stages.
Regardless of whether Solensia is responsible or not though, I am sorry to hear about your cat’s condition and I hope the fluids are going okay at home.
Wish I hadn’t allowed my cat to have Solensia! Day 1 after her first injection, she seemed fine. Day 2 vomit and diarrhea. Day 3 diarrhea and not eating. Day 4 diarrhea, vomit and not eating. Day 4 visit to the vet for anti nausea injection, appetite enticer and probiotic paste (which is impossible to administer by the way). She did eat something though, but constant diarrhea. Day 5 (early morning) 3 bouts of diarrhea already. The stress this is causing her (and me) is awful. Vet informs me the side effects will last until the Solensia wears off. She has Stage 2 CKD so was unable to have NSAIDs. I wish I’d gone with my gut instinct and declined it, instead of being reassured by my vet. Take heed, make an informed decision yourself, don’t be persuaded otherwise. If you have any doubts, even small ones, say no. This drug has not been around long enough to be trustworthy. My worst fear is that this will cause her CKD to deteriorate and she will need to be hospitalised again. I’m so angry at myself. My cat is 10 years old, yes it’s improved her mobility, but at what cost?
Sorry to hear your kitty had a hard time with Solensia. Digestive upset can simply be a side effect that can be seen (and can be seen with a lot of medications), but still only occurs in a small number of cats. Side effects can occur to any medication, and that’s a risk always taken when trying something new. I’m sure your vet was trying to help you find a way to help with your kitty’s mobility, since as you mentioned we have very limited options for kitties. They could not have predicted this outcome either, and the risk vs. benefit is always a discussion I have when starting anything. This outcome does not mean that kidney function will be affected and really we would expect minimal impact on kidney function in early stage disease, and especially not with a single injection. I do think the medication has been out for long enough (about 2 years) to have an idea for what to expect initially with the first couple of injections that still fall within the clinical trials. I do agree that getting past 6-12mo of continuous use is uncharted territory and we should be closely monitoring kidney function in those cases of longer use, especially as CKD progresses. But in the case of a single injection, I would hope the digestive signs will abate with some care at home, though clearly your kitty is not a good condidate to consider further use.
Hi! My cat Jack (20yrs old), great blood work, good teeth and still fairly active, played and purred and talked all the time. He did have some bad hip dysplasia and I wanted to help him with his arthritis pain. After taking the first shot he had more energy and played a bunch, however after a few weeks he stopped eating, dropped 3lbs and started having cognitive issues, almost like dementia. He doesn’t play or purr much anymore, which is really disheartening. I was wondering if these effects will wear off after a month or two? Will he go back to normal, have you heard of this happening and cats returning to baseline? Thank you
Hi Kaitlyn, in response to your post about Jack, behavioral changes have been seen with Solensia, but they are all very individualized. Some have included anxiety, hiding behavior, hypersomnia (excessive sleeping), inappropriate urination, and aggression. Decreased appetite has been seen in about 6-7% of cats and weight loss in about 3%. In this case, it’s unclear if Solensia is related as a 20 year old cat can certainly have something else appear to occur very suddenly that leads to reduced energy, poor appetite, and weight loss. I was not clear if he has had an exam and bloodwork after you started to notice this or not. If not, I would consider getting him rechecked and if no other cause is found, you could discuss discontinuing Solensia with your vet. I have heard of side effects to Solensia dissipating with time, especially behavioral changes, though it could take a couple of weeks depending on when the last injection was given. If Jack has not been evaluated since you started seeing these concerns, I would not take a wait and see approach though, but have him rechecked as soon as you can to try to rule out other causes that could affect any kitty of that age.
My 17.5 year old cat Peanut just got her 3rd shot a week ago. She’s not back to bringing ‘presents’ but does seem just more mobile and resting better. One thing I noticed before the third shot was an increase in her breathing rate at rest but no increase in her work of breathing. Her rate is in the 60-80’s. I mentioned it to my vet and he couldn’t find anything in the literature about that as a side effect. He did listen to her heart and lungs thoroughly though to be sure. None of the major side effects so far. She is longhaired and refuses to be brushed unless she wants to, so there are some hairballs at times. I will get this for her as long as it seems to be working and I feel she is not is pain.
Hi Patsy,
Respiratory changes are also not something I’ve seen reported in the safety studies, even at the lowest percentages. It might also be less associated with Solensia if you noticed this prior to the most recent injection (and not shortly after). While most folks pick up on this, I always mention it, which is that cats who are purring will have an apparent higher respiratory rate (though no increased effort). If she had an increased rate at your vet’s office but there was no purring, then that may be unlikely, but I thought I’d mention it. Stress or overly warm conditions can also lead to a higher rate. Other causes of respiratory changes like primary respiratory disease or heart disease are often accompanied in cats by lethargy and appetite changes, so that would be something to watch closely for if it’s a concern.