Serum samples from 50 dogs and 50 cats were used to compare the serum total T4 concentration obtained with an in-house ELISA kit and a validated T4 radioimmunoassay (RIA) method. Large variations were seen in results from the ELISA kit in comparison to those of the RIA. The T4 concentration was consistently over estimated in the cat serum samples, and results were discordant with the reference RIA in 36-58% of the dog and cat samples. Reliance on the ELISA kit results would have led to misdiagnosis in 62% of canine and 50% of feline samples. The author's of this study concluded that the in-house ELISA kit was not accurate for determining serum total T4 in dogs and cats.
Reference: Lurye, Behrend, Kemppainen. JAVMA 221: 243-249, 2002.

Pancreatic acinar atrophy is by far the most common cause for the maldigestion signs of canine exocrine pancreatic insufficiency (EPI). Evidence for the autoimmune nature of the disease, best termed immune-mediated atrophic lymphocytic pancreatitis, is based upon finding marked T-lymphocyte infiltration during progression of the acinar atrophy and its genetic susceptibility. A single low serum canine trypsin-like immunoreactivity (cTLI) concentration (< 2.5 µg/L), in dogs with typical maldigestion signs has been shown to be highly diagnostic for clinical EPI and is found in dogs with end-stage pancreatic acinar atrophy. Repeatedly subnormal cTLI values (2.5-5.0 µ/L) in dogs with no clinical signs of EPI provide a valuable marker of subclinical EPI and are highly suggestive for partial panceatic acinar atrophy. The primary treatment of EPI is to supplement each meal with pancreatic enzymes, which gives a good long-term treatment response in about 50% of the dogs.
Reference: Westermarck , Wiberg. Vet Clin N Am Sm An Pract 33: 1165-79, 2003.

Although pancreatitis is common in dogs and cats, many cases remain undiagnosed. Serum amylase and lipase activities are useful as quick screening tests for pancreatitis, but only in the dog. The diagnosis is suggested when concentrations are at least 3-5 times the reference range, but must be confirmed by further diagnostics. Normal test results do not preclude the possibility of pancreatitis. Abdominal ultrasound is highly specific for pancreatitis in dogs and cats but is not particularly sensitive, especially in cats. In dogs, serum pancreatic lipase immunoreactivity (cPLI) concentration is highly specific and sensitive for exocrine pancreatic function and pancreatitis. Similarly, initial data in cats suggest that serum fPLI is the most sensitive and specific diagnostic test for feline pancreatitis. Histopathologic evidence of pancreatitis is conclusive for a diagnosis of pancreatitis, but the lesions are often localized and may not be detected.
Reference: Steiner. Vet Clin N Am Sm An Pract 33: 1181-95, 2003; Williams et al. Proc ACVIM Forum, 2003; Forman et al. Proc ACVIM Forum, 2003.