A cat was brought to my hospital several months ago. She had a history of episodic vomiting. She would be devoid of symptoms for several weeks, or sometimes months, but then would suffer from several days of severe vomiting. The owners mentioned that blood tests in the past had shown slight irregularities with her liver. I immediately became suspicious of a diagnosis: triaditis.

Another cat had a four-month history of poor appetite, lethargy, and weight loss. His coat was dull, and he appeared chronically dehydrated. Among the possible causes was triaditis.

A cat came to me with a sudden onset of severe vomiting. She had held nothing down for 36 hours. She had seemed perfectly healthy before the vomiting started. Might she have ingested a foreign body? Could it be triaditis?

In fact, all three cats ultimately were diagnosed with triaditis. That raises a question: What in the world is triaditis?

The medical definition of triaditis won’t be of much help to most people. Triaditis is a syndrome in which cats suffer from concurrent pancreatitis, inflammatory bowel disease, and cholangitis. If you haven’t guessed by now, triaditis is a nebulous condition that is poorly understood.

Let’s break the subject down. The pancreas is an organ (and also a gland) located in the abdomen. It is situated near the outlet of the stomach, and one of its roles is to produce digestive enzymes. These enzymes pass through a duct into the intestines, where digestion occurs and nutrients are harvested. Pancreatitis is condition in which the pancreas becomes inflamed or irritated.

In humans, pancreatitis is linked to alcoholism. In cats, obviously, it is not. In dogs, pancreatitis is linked to consumption of high-fat diets and to certain medications. In cats, not so much. Feline pancreatitis is a very mysterious and poorly understood syndrome.

Inflammatory bowel disease is a syndrome in which the intestines become chronically inflamed. One of its features is infiltration of the intestines with cells from the immune system. The condition now is believed to be linked to lymphoma, the most common cancer in cats. It appears that inflammatory bowel disease may morph into lymphoma over time.

Cholangitis is a term that means inflammation of the bile duct. Bile is produced by the liver. Bile is stored in the gall bladder, and then passes through the bile duct (which in cats merges with the pancreas’ duct) into the intestines, where it aids in digestion.

Triaditis is a combination of these three things. Why do they occur together? The answer appears to lie in anatomical proximity. The pancreas and the bile system share a duct, and both drain into and are located adjacent to the intestines. They work together as a system, and triaditis occurs when the system becomes inflamed.

The symptoms of triaditis vary wildly among individuals. Some cats may experience explosive vomiting. Others may have episodic vomiting or poor appetite. Others may have vague symptoms that might include weight loss, poor appetite, abnormal stools, hiding, lethargy, jaundice, abdominal pain, and a dull coat.

What causes triaditis? That is a million dollar question, and nobody knows the answer. Current theories involve dietary allergens that stimulate the immune system, hereditary factors, and the impact of bacterial infections that move from the intestines into the bile duct. Many experts believe that most cases of triaditis start in the bile duct, with the inflammation then flaring up in the pancreas and intestines.

The diagnosis of triaditis can be challenging. A definitive diagnosis requires biopsies of the affected organs. Few cats undergo such testing, because biopsies are the opposite of non-invasive testing.

Blood tests and imaging can offer significant insight when triaditis is suspected. Blood tests can reveal changes in the liver and bile duct, and a special test test of the pancreas can give insight into that organ. X-rays help to rule out other causes of the symptoms. Ultrasound can give insight into all three of the structures in question. In my experience, most cases of triaditis are diagnosed through ultrasound.

Treatment is symptomatic. If a bacterial infection is suspected, antibiotics may be administered. Gastrointestinal protectants often are prescribed. Anti-nausea medications may be beneficial. Pain killers and appetite stimulants frequently are used. Steroids such as prednisolone or budesonide may be used to reduce the impact of inflammatory bowel disease.

A mainstay of treatment may be dietary modification. Specifically, hypoallergenic diets may reduce the impact of the immune system in cats with the condition. In my experience, dietary modification alone may be sufficient to control the symptoms in cats with mild cases of triaditis.

The prognosis for cats with triaditis is fair. The condition cannot be cured, but in most cases it can be controlled. Talk to your vet if your cat is experiencing symptoms compatible with triaditis.

Read more on cats and health:

• 5 Things I Did Wrong When I Took My Cat to the Vet
• Has Your Cat Ever Given Your Vet a Funny Story?
• 11 Cat Emergencies That Need Immediate Veterinary Attention

Got a question for Dr. Barchas? Ask our vet in the comments below and your topic might be featured in an upcoming column. (Note that if you have an emergency situation, please see your own vet immediately!)