Biochemical changes in the small intestine during development of naturally acquired wheat-sensitive enteropathy of Irish Setters were investigated. To distinguish primary biochemical abnormalities from secondary effects of intestinal damage, progeny of affected dogs reared on a normal wheat-containing diet were compared with their own littermates reared on a cereal-free diet and with age-matched clinically normal Irish Setters fed the same wheat-containing diet. Peroral jejunal biopsy specimens were sequentially obtained between weaning and 1 year of age; specific activity and reorientating sucrose density-gradient distribution of organelle marker enzymes were determined. Major primary biochemical abnormalities were not detected in affected progeny. In affected dogs fed wheat, there was a selective, but secondary, loss of the brush border alkaline phosphatase and aminopeptidase N activities. This loss was associated with the development of partial villus atrophy, but represented a specific effect of dietary wheat on the brush border, not merely a nonspecific effect of mucosal damage, because other brush border enzymes, including disaccharidases, were not similarly affected. Increased soluble activities of lysosomal and peroxisomal marker enzymes late in the disease process may represent alterations in these 2 organelles as a secondary consequence of mucosal damage.

Reference intervals are reported for feline CSF biochemical and serologic variables, IgG concentration, and electrophoretic fractionation, derived from 58 clinically normal adult cats that did not have histologic lesions of the CNS. There was no apparent effect of age on any variable. The CSF total protein concentration was significantly (P = 0.012) greater in males than in females, but all other variables were unaffected by gender. The only variable that had a statistically significant correlation with its corresponding blood concentration was IgG. Blood contamination of the CSF affected the following CSF variables: total protein concentration, activities of lactate dehydrogenase and creatine kinase, IgG ratio, and gamma-globulin percentage. The reference intervals proposed for feline CSF were derived from 33 cats with CSF RBC count < 31 cells/microliter. Reference limits for CSF with 31 to 1,700 RBC/microliter also are reported.