Triaditis in the Cat
Just For Cats Veterinary Hospital
Dr. Kari Mundschenk
As mentioned in previous discussions, cats are not the some as dogs or humans. They have unique nutritional requirements and their anatomy predisposes them to various complex diseases. Triaditis is a particular syndrome in cats in which intestinal inflammation extends beyond the gastrointestinal tract and affects the liver (+/- the gallbladder) and pancreas. These cats may present with signs attributable to these organs, which may or may not include vomiting and diarrhea.
Based on the cat's anatomy and physiology, it is "logical" to understand why this may occur. Since the common bile duct and pancreatic ducts join a common channel before they enter the duodenum, extension of inflammation and luminal contents in both directions is common. I.e.--if there is pathology in the distal common bile duct, either ascending from the duodenum or originating in the duct itself, (such as infection or cholelithiasis), this could predispose to pancreatitis because of the functional relationship between the major pancreatic and common bile duct sphincters in the cat.
Each part of the triad alone can have a similar clinical presentation often associated with chronic intermittent vomiting, lethargy, and anorexia. Likewise, each part of the triad can present as a solitary disease. It is reported that in most cases of triaditis, the predominant signs are attributable to hepatobiliary disease, with pancreatitis and IBD occurring as secondary complications. In general, most problems are associated with inflammation and cellular diagnosis is necessary to confirm diagnosis and institute appropriate treatment.
We will now briefly discuss the three major components of triaditis.
Pancreatitis in the cat can present as an acute necrotizing disease as in the dog or more commonly as a chronic, relapsing non-suppurative pancreatitis or two types of cancer. Neoplosia is rare yet needs to be ruled out. There are many "causes" of pancreatitis yet it all boils down to something such as trauma, drugs, etc. which cause an altered blood flow to the organ. Signs of pancreatitis may include lethargy, reduced appetite, dehydration, and a low body temperature. Additionally, an increased respiratory rate, abdominal pain and vomiting/diarrhea may be noted. As one can see, these signs can go along with many diseases.
Having an index of suspicion is the most important tool in order to diagnose the problem. Diagnosing pancreatitis in the cat is not as straightforward as the dog. In the dog, there are specific lab parameters such as an increased amylase and lipase. In the cat, lab parameters are non-specific and any elevation in amylase/lipase usually indicates kidney dysfunction rather thon pancreatitis. Radiographs, CT and MRI scans are of little use in diagnosing pancreatitis. A newer laboratory test, fPLI, shows promise and studies are still going on. Ultrasound is the most useful diagnostic tool when used by an experienced ultrasonographer. Biopsy is still the gold standard for a specific diagnosis.
The mainstay of treatment is to control pain, correct fluid/electrolyte imbalances and provide nutritional support (which may include the use of feeding tubes). Antibiotics should be avoided unless evidence of sepsis is noted. Additionally, corticosteroids should only be used if absolutely indicated. Prognosis depends on the type of pancreatitis (acute vs. chronic) as well as the degree of duration and severity. As mentioned at the beginning of the paper, one should continue to monitor for liver and gastrointestinal involvement.
Feline cholangitis is an inflammatory disorder of the hepatobiliary system. A recent classification system by the WSAVA liver standardization Group recognizes three distinct forms of cholangitis: Acute neutrophilic (suppurative) and chronic neutrophilic (chronic neutrophilic, mixed) and lymphocytic-plasmacytic (immune mediated) cholangitis. It is probable that the acute and chronic forms of cholangitis represent different stages of one disease.
The acute form is thought to be the result of an ascending bacterial infection. Some cats will also show on association with pancreatitis, cholelithiasis or even biliary obstruction. Cats with this syndrome are usually young (3-5 years) and present with acute illness usually a week or less in duration. They may have a fever, anorexia, vomiting or lethargy. A biopsy is required for specific diagnosis and a culture is needed to ensure appropriate antibiotic therapy. Ultrasound can be used to check for concurrent disease. Therapy is aimed at correcting fluid and electrolyte disorders and treating with appropriate antibiotics. Antibiotic use may be extended. Specialized liver support is also necessary.
The chronic form of the disease is usually seen in middle aged and older cats and has a long duration of signs being weeks to months. Presenting signs include vomiting, lethargy, and anorexia. Diarrhea is uncommon. Signs may come and go and weight loss may be present. Jaundice is present in most kitties. Biliary changes are usually present so lab will reflect these changes. A liver biopsy confirms the diagnosis and separates it from neoplasia, hepatic lipidosis and other liver diseases. Treatment is aimed at decreasing inflammation and the immune response, controlling infection if warranted and providing liver support.
Lymphocytic cholangitis is felt to represent a later stage of neutrophilic cholangitis, or may stand alone as a separate disease entity. It is characterized by a moderate to marked infiltration of the portal areas by small lymphoctytes +/- biliary hyperplasia, portal or periductal fibrosis, or bridging fibrosis. One study found 83% of affected cats had inflammatory bowel disease and 50% had chronic pancreatitis.
It is important to note that the classification of cholangitis is still evolving as research looks into causes. Treatment is based on biopsy results and instituting the appropriate supportive core.
Feline Inflammatory Bowel Disease (FIBD) is an important disease characterized by persistent gastrointestinal signs, histological evidence of mucosal inflammation and general responsiveness to immunotherapeutic intervention. It is one of the most common histological diagnoses in cats with chronic vomiting or diarrhea. Other common causes include giardia/parasites, food intolerance, neoplasia and metabolic disease. There is some discussion if FIBD is a precursor to lymphocytic lymphoma. The cause of FIBD is unknown and the disease is most common in middle-aged cats with no apparent gender predisposition. There may be a predisposition in Siamese cats. Large bowel forms of FIBD and Protein Losing enteropathy occur rarely in cats.
A diagnosis of FIBD is one of exclusion with the following parameters:
1) persistent GIT signs
2) failed responses to dietary trials alone
3) exclusion of other causes of GIT inflammation
4) histopathological evidence of mucosal inflammation.
Treatment includes the use of elimination diets, fiber supplementation if colitis is present, and anti-inflammatory/immunosuppressive drug therapy. One must also treat concurrent disease and provide nutritional support if indicated. Again, the WSAVA is working on standardization of histopathology samples to assist with specific diagnosis and treatment.
So now you have it; triad disease is a complex syndrome which involves the biliary, pancreatic and intestinal system of the cat. As always, diagnosis is by elimination of other causes and histopathology is the gold standard. Care can be long term and rewarding if diagnosed and managed accurately and in a timely manner. As always, a lifetime of good care and attention to the subtle signs will assist with an early diagnosis.