Practical Interpretation and Application of Exocrine Pancreatic Testing in Small Animals

Serum pancreatic lipase immunoreactivity in sick dogs after chronic administration of supraphysiologic doses of glucocorticoids

BACKGROUND

Glucocorticoids (GC) are commonly used for a long term to treat a multitude of immune-mediated, inflammatory, and neoplastic diseases in dogs. Conflicting results of published studies on the effects of exogenous and endogenous GCs on serum canine pancreatic lipase immunoreactivity (cPLI) raise the question of whether cPLI concentrations can be reliably interpreted in patients receiving GCs.

OBJECTIVE

We sought to determine the effect of long-term GC administration at supraphysiologic doses on serum cPLI concentrations in sick dogs.

METHODS

Serum samples were collected from 35 client-owned dogs. Dogs were administered prednisone at a dose of ≥0.5 mg/kg per day for ≥3 weeks. Serum cPLI was measured prior to the initiation and after ≥3 weeks of GC therapy.

RESULTS

There was a significant increase in serum cPLI between baseline (median 101 μg/L; range 30-1997 μg/L) and following the administration of ≥0.5 mg/kg/day of prednisone (median 173 μg/L; range 30-2000 μg/L) in dogs (P = 0.025). However, the median change was small (31 μg/L). There was no suspicion of pancreatitis in any of the dogs. Diagnostic interpretation changed in 6/35 dogs, with no apparent dose-response relationship.

CONCLUSIONS

There was a statistically significant difference from baseline in serum cPLI measurements in sick dogs receiving long-term prednisone. Although the change was small and often clinically insignificant, it could pose a clinical interpretation dilemma in some dogs. It is unknown whether these observations are coincidental due to subclinical pancreatitis or caused by another effect of GCs on pancreatic acinar cells.

How useful is abdominal ultrasonography in dogs with diarrhoea?

OBJECTIVE

To assess the utility of abdominal ultrasonography in the diagnostic work-up of dogs with diarrhoea.

METHODS

Retrospective cross-sectional study based on a referral population of dogs with diarrhoea. Associations between the clinical signs, use of abdominal ultrasonography, results of abdominal ultrasonography and subsequent work-up were examined. The utility of abdominal ultrasonography was scored as high, moderate, none or counterproductive based on review of medical records.

RESULTS

Medical records of 269 dogs were reviewed, of which 149 (55%) had abdominal ultrasonography. The most frequent result was no ultrasonographic abnormalities affecting the intestine in 65 (44%) dogs. Ultrasonography results were associated with subsequent work-up as follows: (1) no detected abnormalities and dietary trial; (2) focal thickening of the intestinal wall, loss of intestinal wall layers or enlarged abdominal lymph nodes and ultrasound-guided fine-needle aspirates; (3) diffuse thickening of the intestinal wall or hyperechoic striations in the small intestinal mucosa and endoscopy; and (4) small intestinal foreign body and coeliotomy. Abdominal ultrasonography was considered to be diagnostic without further testing in only four (3%) dogs: two had a portosystemic shunt identified ultrasonographically, one had a linear foreign body and one had a perforated pyloric ulcer. Abdominal ultrasonography had moderate utility in 56 (38%) dogs and no utility in 79 (53%) dogs. Abdominal ultrasonography was considered counterproductive in 10 (7%) dogs because results were either falsely negative or falsely positive.

CLINICAL SIGNIFICANCE

These results should prompt clinicians to reconsider routine use of abdominal ultrasonography in dogs with diarrhoea.

Canine Pancreas-Specific Lipase and C-reactive Protein in Dogs Treated With Anticonvulsants (Phenobarbital and Potassium Bromide)

Animals treated with anticonvulsant drugs may have increased canine pancreas-specific lipase (cPLI) values. Inflammatory conditions and specifically acute pancreatitis are of major concern in these animals. Elevation in C-reactive protein is being associated with inflammatory status in dogs and it has been correlated with the clinical severity of pancreatitis. In the present study, we investigated if there is a correlation between the cPLI increase, changes in C-reactive protein and hepatic enzymes, as well as the incidence of severe acute pancreatitis (AP) in dogs with anticonvulsant treatment (phenobarbital, or potassium bromide or both). Increased values of pancreas-specific lipase were found in 6.8% of the animals in treatment with anticonvulsants, and this increase is correlated with the increase in triglycerides, alkaline phosphatase, and alanine aminotransferase but not with C-reactive protein levels, which suggests a possible induction or release phenomenon rather than a clear severe AP. C-reactive protein levels did not affect cPLI values on the population studied. Only 2 animals had clinical and analytical data suggestive of AP, indicating a low prevalence (0.6%). In conclusion, cPLI may be increased in a low percentage of animals with anticonvulsants treatment and its increase may not be associated with severe AP. It may be induced by the anticonvulsants drugs; however, further studies are advised to rule out other possible causes that increased cPLI.