Acute feline pancreatitis

Introduction

Pancreatitis in cats is a very common disease: in one retrospective study, 67% of 115 cats had histological lesions found on post-mortem examination 1. However, the condition is also probably underdiagnosed, as many of the clinical signs associated with feline pancreatitis are very non-specific. The etiology of pancreatitis in cats is, as with dogs, largely unknown; however, unlike the situation in dogs, dietary indiscretion is not a common cause in cats. However, one specific consideration is to include toxoplasmosis as a potential infectious cause of feline pancreatitis 2. Other etiologies that have been associated with acute onset of pancreatitis in cats are recent general anesthesia, hypoxia secondary to acute heart failure episodes, and organophosphate intoxication.

Clinically, cats with pancreatitis show less specific signs than dogs, with anorexia, lethargy, dehydration, weight loss, hypothermia, vomiting, icterus and fever being amongst the most common signs. In a few cases, abdominal pain can be present, and the patient may also have diarrhea. However, it is important to consider the possibility that any cat with suspected pancreatitis could have abdominal pain, and appropriate treatment may greatly improve the clinical demeanor of the cat.

Diagnosis

On hematology, many affected cats show anemia or hemoconcentration; either leukocytosis or leucopenia is also common. The biochemistry profile often includes hypoalbuminemia, which can also be a negative prognostic indicator. Hypocalcemia may also be present (from saponification of the mesenteric fat) and should be treated if present.

On radiography it is occasionally possible to identify bicavitary effusion (i.e., effusion in both pleural and peritoneal cavities) in affected cats. As noted above, hypoalbuminemia is a common finding in feline pancreatitis, and can also contribute to this. Ultrasound is often employed to help with the diagnosis of pancreatitis, but has been shown to have very variable sensitivity, between 10-70%. This is dependent on the experience of the ultrasonographer, as well as the severity of clinical signs. In acute pancreatitis, the sensitivity of ultrasound is much higher than in chronic cases. Typical signs on ultrasound are hyper- or hypoechogenic pancreatic tissue, free fluid surrounding the pancreas, and hyperechogenic mesenteric fat.

Feline pancreatic lipase (fPLI) or DGGR lipase assay are the laboratory tests that currently offer the best sensitivity and specificity for the diagnosis of pancreatitis in cats, when compared with histological identification of pancreatitis as the gold standard. Since we do not know how relevant histological pancreatitis is in the clinical setting, the results of these tests must be carefully interpreted in light of other clinical findings. In fact, feline pancreatitis is always a clinical diagnosis and diagnosis should never be made on the basis of a single test, but rather based on a combination of clinical signs, laboratory and ultrasound findings.

In a recent large retrospective study of 157 cats with pancreatitis, hypoglycemia, azotemia, pleural effusion and persistent anorexia during hospitalization were the factors most commonly associated with poor outcome 3. This hints towards the importance of nutritional support, which is most often best achieved by naso-esophageal or esophageal tube feeding (Figure 1). Furthermore, withholding antibiotic treatment was associated with a poorer outcome in these cats. This is an important finding, and concurs with recent literature indicating bacterial infections in cats with pancreatitis. It is assumed that bacterial infection of the liver and pancreas is a result of ascending infection from the upper small intestine through the bile and pancreatic ducts. Most commonly, bacterial DNA from E.coli species have been found to be present in such cases 4. It is therefore prudent to assume bacterial infection with enteral species in severely sick acute pancreatitis cases, and to empirically treat with antibiotics.

Medical treatment

As mentioned above, analgesia is very important for all cats with pancreatitis. The best options are morphine derivatives such as buprenorphine administered parenterally. Anti-emetics should also be given; maropitant and ondansetron, sometimes in combination, have empirically been shown to have good efficacy in these cases. Furthermore, although dopamine D₂ receptors have historically not been reported to occur in cats, metoclopramide may have an effect on functional ileus in feline pancreatitis, and can therefore also play a role in the management.

Nutritional management