Canine hypothyroidism is very similar to Hashimoto's lymphocytic thyroiditis in humans, which has been shown to be associated with major histocompatibilty (MHC) tissue antigens. A study of canine MHC genes has identified a particular MHC allele, DLA-DQA1*00101, in dogs with autoimmune thyroiditis, which doubles the risk of these dogs developing hypothyroidism. This rare DLA class II haplotype was found in affected Doberman pinschers, English setters, and Rhodesian ridgebacks, but was not present in affected boxers.

Several breeds (Siberian husky, shih tzu, Yorkshire terrier), not represented in the disease group, did not carry this DLA allele within their populations. Discovery of this genetic marker could provide a useful tool for selecting breeding stock to reduce the incidence of thyroiditis in pure-bred dogs.

References: Kennedy et al, Tissue Antigens 67:53-56, 2006; Ibid. 68:82-86, 2006; Happ et al, AKC Can Res Fdn Ann Report, 2005.

Clinicopathologic features, response to treatment, and risk factors were evaluated in dogs with idiopathic neutropenia. Medical records, signalment, history, clinical signs, and response to treatment were recorded for 11 idiopathic neutropenia cases, and compared with that of dogs with neutropenia attributable to known causes and to dogs without neutropenia (controls).

Dogs with idiopathic neutropenia had lower neutrophil counts and were younger (< 4 years old) than those with neutropenia attributable to known causes and control dogs. In all dogs with idiopathic neutropenia, remission of neutropenia occurred within 18 days after administration of prednisone (2 to 4 mg/kg PO, daily) and no serious complications or infections developed. These findings suggest an immune-mediated pathogenesis.

Reference: Brown et al, JAVMA 229:87-91, 2006.

Motivation and feeding practices of people who fed vegetarian diets to their cats were determined along with the taurine and cobalamin status of these cats. The study group consisted of 34 cats that had been exclusively fed a commercial or homemade vegetarian diet and 52 cats that had been fed a conventional diet for >/= 1 year. Caregivers of cats in both groups answered a telephone questionnaire regarding feeding practices for their cats. Blood was obtained from a subset of cats that had been fed vegetarian diets. Blood and plasma taurine and serum cobalamin concentrations were measured.

Vegetarian diets are fed to cats primarily for ethical considerations. People feeding these diets were more likely than those feeding conventional diets to believe in the health benefits of a vegetarian diet and that commercial cat foods are unwholesome. Both groups were aware of the potential health problems that could arise from improperly formulated vegetarian diets. All cats evaluated had serum cobalamin concentrations within reference range, and 14 of 17 had blood taurine concentrations within reference range.

Reference: Wakefield, Shofer, Michel, JAVMA 229:70-73, 2006.