Feline Cholangiohepatitis
Cholangitis is inflammation of the gallbladder and bile ducts, while the term cholangiohepatitis is used if there is also inflammation of the surrounding liver tissue.
Cholangitis in cats can be divided into two types; neutrophilic cholangitis, an acute inflammation often due to bacterial infection, and lymphocytic cholangitis, a chronic immune-mediated inflammation, often associated with conditions like inflammatory bowel disease.
If cholangiohepatitis occurs at the same time as pancreatitis (inflammation of the pancreas) or enteritis (inflammation of the small intestine), it may be referred to as triaditis. In cats, the small ducts from the gallbladder and pancreas combine before entering the intestine, and it is believed that this anatomical link leads to development of triaditis, possibly due to bacteria ascending from the intestine.
Which tests are used to diagnose Feline Cholangiohepatitis?
Biopsies of the liver and gallbladder may be the only way to gain a definitive diagnosis, but these are very rarely required. Instead, non-invasive tests provide a strong index of suspicion and guide treatment.
Blood tests
Blood tests typically show elevation of liver enzymes and bile acids with cholangitis, as well as an increase in white blood cells. Other changes may suggest concurrent chronic enteritis or pancreatitis.
Ultrasound
Ultrasound provides the best mechanism of viewing the gallbladder, bile ducts and liver. Changes seen can include distension of the gallbladder and bile ducts, thickened gallbladder wall, and sludge within the gallbladder. Changes are typically more pronounced with neutrophilic cholangitis and may be minimal in lymphocytic cholangitis. Ultrasound also allows assessment of the pancreas and intestines. Ultrasound may be repeated to monitor improvement during the course of treatment.
Bile analysis
Occasionally a small sample of bile may be taken out of the gallbladder with a fine needle; this allows testing for bacterial infection to confirm diagnosis and guide antibiotic choice. This can be a challenging procedure to perform safely, so may not be offered in all clinics.
How is Feline Cholangiohepatitis treated?
Treatment of cholangitis/cholangiohepatitis will depend on which type is suspected. Depending on the severity of disease cats may need to be admitted for inpatient care. Treatment may include:
Antibiotics
Neutrophilic cholangitis is usually due to bacterial infection. Broad-spectrum antibiotics are used, with bile sampling for culture considered if there is poor response. Antibiotics may need to be given for 2-6 weeks depending on severity. Lymphocytic cholangitis may be treated with antibiotics if there is suspicion of secondary infection.
Steroids
Lymphocytic cholangitis is immune-mediated, so treatment requires suppression of the immune system. This is most often achieved using steroids, though other medications may be added depending on response.
Cats with cholangitis/cholangiohepatitis also require supportive care:
Fluids
Many patients are dehydrated and may be lacking in electrolytes due to vomiting and inappetence. Fluids are usually provided intravenously, using a drip.
Pain relief
Cholangiohepatitis can be painful, especially if there is concurrent inflammation of the pancreas, which contributes to inappetence. Often strong, opioid based drugs are required to control discomfort.
Medications
Depending on the symptoms shown, other medications are used including anti-nausea, gastro-protectants, and hepatic support (if the liver is affected).
Feeding
Although most patients don't want to eat, feeding is extremely beneficial to the recovery process. Controlling pain and nausea will help, and in some patients appetite stimulants are used. In severe cases a feeding tube may be recommended. Long-term, cats with lymphocytic cholangitis and/or chronic enteritis may require a prescription diet for management.
What is the outlook for cats with Cholangiohepatitis?
The prognosis for cholangitis is variable. Neutrophilic cholangitis is often very treatable and mildly affected cats usually make a full recovery. More severely affected cats may need prolonged hospitalisation. Some long-term monitoring is advisable however once the episode has resolved, recurrence is rare.
Lymphocytic cholangitis is a chronic condition, so treatment aims to manage rather than cure. Treatment is likely to be given for several months and can be slowly reduced provided symptoms are under control. Cats are always at risk of the condition relapsing; however, this does not necessarily affect life expectancy, and many cats remain well controlled for years.
