Bile Duct Obstructions in Cats: Causes, Symptoms, and Treatment

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For cats and humans alike, the liver produces bile and stores it in the gall bladder. After eating, the bile is released down the bile duct into the small intestine to help digest food. A bile duct obstruction, or cholestasis, occurs when the tube that carries bile from the gall bladder to the small intestine becomes blocked. If the bile cannot flow into the intestine, it can build up in the gall bladder, causing painful illness.

Other Names: Cholestasis, biliary obstruction

Common Symptoms: Vomiting, lethargy, poor appetite, weight loss, jaundice, dark urine, pale stools

Requires Ongoing Medication: Required in some cases, may include liver supplements or a special diet

Vaccine Available: No

Treatment Options: Can be treated with either surgery or medication, depending on the underlying cause.

Home Treatment: Requires urgent and specialist care from a veterinarian. Cannot be managed at home.

There are a number of reasons why bile ducts can become blocked in cats. Often, it occurs because a nearby organ has become inflamed, pressing against the duct. But there are many other causes, including gallstones and even internal parasites. The diagnosis and treatment of bile duct obstructions depend on what is causing the obstruction. Read on to learn why this condition occurs in cats and what to look out for in your own cat.

Causes of Bile Duct Obstruction

The opening of the bile duct into the duodenum (the beginning of the small intestine) is very small, so it can become blocked quite easily. Most commonly, blocked bile ducts in cats are caused by inflammation of a nearby organ, such as the liver (including the gall bladder), pancreas, or small intestine. When these organs become inflamed or swollen, they can put pressure on the bile duct and prevent the bile from flowing through. This is why bile duct obstructions often happen alongside other diseases, such as:

• Pancreatitis
• Cholangiohepatitis (inflammation of the liver and gall bladder)
• Inflammatory bowel disease

In cats, these three diseases often occur at the same time, resulting in a syndrome called “triaditis”. This is because the pancreas, liver (and gall bladder), and small intestine all sit very closely together in cats, meaning inflammation in one organ can quickly spread to the other two. Triaditis often leads to bile duct obstruction in cats.

However, there are many other potential causes of blocked bile ducts in cats, including:

• Gallstones (also called cholelithiasis)
• Biliary sludge
• Cysts in the liver or bile duct
• Parasites (eg. liver flukes)
• Tumors
• Intestinal foreign bodies
• Congenital (pre-birth) malformations
• Scar tissue from previous infections or abdominal surgery

Symptoms of Bile Duct Obstruction

Cats with bile duct obstructions can become very unwell quickly, or the symptoms can wax and wane over a few weeks. Unfortunately, many of the symptoms are not specific and can look like other abdominal conditions. This makes it a tricky condition to diagnose. But the common symptoms of bile duct obstructions include:

• Lethargy
• Vomiting
• Diarrhea
• Either lack of appetite or excessive hunger
• Weight loss
• Jaundice (a yellow tinge to skin, eyes, and mucous membranes)
• Dark yellow/orange urine
• Pale-colored stools
• Abnormal bleeding
• Abdominal pain

Complications of Having Bile Duct Obstruction

If an obstructed bile duct is not treated, the bile can build up in your cat’s gall bladder. This can lead to bacterial infection and liver damage. Unfortunately, some cats can be left with long-term problems with their livers and gallbladders.

Therefore, it is important to take your cat to the veterinarian if they show any symptoms of an obstructed bile duct. Many cats will make a full recovery if the underlying problem is resolved quickly.

Diagnosis of Bile Duct Obstructions

A cat with a bile duct obstruction may have waxing and waning symptoms and need a variety of veterinary tests to determine the problem. megaflopp/Shutterstock.com

As the symptoms of bile duct obstructions in cats aren’t specific to the condition, your veterinarian will usually have to perform a range of tests to diagnose it. This will always start with a detailed history from you and a thorough clinical examination of your cat.

Next, your veterinarian will run blood and urine tests. This will help to determine not only the cause of the bile duct obstruction but also the effects of it on your cat’s body. Your veterinarian will look for high levels of bilirubin, a component of bile that can build up if bile flow is obstructed.

As bile duct obstructions are caused by something physically blocking the duct, your veterinarian will usually recommend imaging to look inside their abdomen. An ultrasound of their abdomen will allow your veterinarian to check for enlargement of the bile duct (which suggests an obstruction) as well as look for what may be causing the obstruction. They may also recommend an x-ray.

Sometimes, your veterinarian may recommend exploratory surgery if lab tests and imaging aren’t able to find the cause of the problem. This will allow them to visualize the problem, as well as take samples (biopsies) from any unusual tissue. Depending on what is causing the obstruction, they may even be able to correct it during the surgery.

Treatments for Bile Duct Obstruction

The treatment for bile duct obstructions centers on relieving whatever is causing the obstruction, which may be through surgery, medical treatment, or even dietary change.

Surgical Treatment of Bile Duct Obstruction

If your cat has a foreign body, tumor, cyst, large gallstones, parasites, or severe pancreatitis, it is likely they will need surgery. Most cats undergoing surgery of the biliary tract will receive antibiotics, as infections during this surgery can be very serious. Surgery of the bile duct is very complex, so your veterinarian may wish to refer you to a specialist surgeon.

If your cat needs surgery for their bile duct obstruction, they have a 50-60% chance of surviving, as long as they do not have cancer. Whilst surgery can be curative, some cats may experience long-term complications such as:

• Recurrence of the obstruction
• Cholangiohepatitis (inflammation or infection of the liver and gall bladder)
• Chronic weight loss

All cats who undergo surgery of the biliary tract will require extensive aftercare. This often includes pain management, intravenous fluid therapy, and antibiotics. Cats will also often need a feeding tube placed in their nose or neck for the first few days.

Sadly, obstructions caused by cancer carry a very poor prognosis and most cats will not recover.

Medical Treatment of Bile Duct Obstruction

Some cases of bile duct obstructions are caused by other diseases, which can be treated with medication. This includes pancreatitis, cholangiohepatitis, inflammatory bowel disease, and small gallstones. Medications your veterinarian may recommend include:

• Intravenous fluid therapy: Cats with bile duct obstructions often become dehydrated as they stop eating and drinking enough. If your cat is dehydrated, your veterinarian will give them fluids into their vein in the hospital to rehydrate them.
• Pain relief: Many of the causes of bile duct obstructions are painful for your cat. Your vet may prescribe a range of types of pain relief, including non-steroidal anti-inflammatories or opioids.
• Antibiotics: Obstruction of the bile duct commonly leads to bacterial infection in the liver and gall bladder. Antibiotics can help to prevent or treat this.
• Anti-sickness medications: Many cats with obstructed gallbladders suffer from nausea or vomiting. Anti-sickness medications can help them to feel better and start eating more quickly.
• Liver medications: Depending on the cause of the obstruction, your veterinarian may prescribe medication that helps to protect the liver, such as ursodiol or S-Adenosyl-L-methionine (SAMe)
• Anti-parasitics: In rare cases, certain parasite infections (such as liver fluke) can become severe enough to cause an obstruction. Usually, these will need surgery to remove the blockage, alongside anti-parasitic drugs.
• Dietary management: Cats with bile duct obstructions may require a special diet that is low in fat and easily digestible to help the gall bladder and liver recover. They may need to stay on this diet long-term.

Cat Care Tips

Recovering cats always appreciate a warm, safe and comfortable place to rest. Leoniek van der Vliet/Shutterstock.com

Cats recovering from bile duct obstructions need a lot of care. Whilst they are likely to require specialist care in hospital initially, there is still a lot you can do to help them recover once they are home.

• Prepare a quiet area for them to recover: Your cat will need lots of rest when they get home, particularly if they have had surgery. Creating a soft, quiet area for them to recuperate can help them get the rest they need. Try to find a spot that is away from the hubbub of daily life but still easy for you to keep a close eye on them. You can use pheromone diffusers to create a calm and relaxing environment.
• Follow your veterinarian’s instructions carefully: Your cat will probably be discharged with multiple medications and need to attend regular follow-up visits. Making sure you give them all their medications on time and attending appointments will ensure they recover as well as possible. It can help to make a chart of all their medications to tick off – particularly if there are a few people at home.
• Ask your veterinarian about a special diet: Diets that are easily digestible, calorie-dense, high in protein, and low in fat can help the liver and gallbladder recover. Ask your veterinarian whether a special diet could be helpful for recovery or for preventing the problem from recurring.
• Call your veterinarian if you are worried: Cats with bile duct obstructions are at risk of complications and long-term issues, so it is vital to identify and treat any problems quickly.

Prevention of Bile Duct Obstruction in Cats

Bile duct obstruction occurs as a result of a number of conditions. So, there aren’t specific risk factors or steps you can take to prevent it from happening. It’s just a case of keeping your cat as fit and healthy as possible, so they’ve got less chance of falling ill at all.

Some of the most important ways you can do this are:

• Feed them a high-quality diet
• Prevent them from becoming overweight
• Ensure they receive recommended vaccinations
• Use anti-parasiticides regularly
• Take them for regular check-ups with your veterinarian
• Always get any worrying symptoms checked out straight away