Alopecia areata in Eringer cows.

Alopecia areata is a hair loss disorder in humans, dogs and horses with a suspected autoimmune aetiology targeting anagen hair follicles. Alopecia areata is only sporadically reported in cows. Recently, we observed several cases of suspected alopecia areata in Eringer cows. The aim of this study was to confirm the presumptive diagnosis of alopecia areata and to define the clinical phenotype and histopathological patterns, including characterization of the infiltrating inflammatory cells. Twenty Eringer cows with alopecia and 11 Eringer cows without skin problems were included in this study. Affected cows had either generalized or multifocal alopecia or hypotrichosis. The tail, forehead and distal extremities were usually spared. Punch biopsies were obtained from the centre and margin of alopecic lesions and normal haired skin. Histological examination revealed several alterations in anagen hair bulbs. These included peri- and intrabulbar lymphocytic infiltration, peribulbar fibrosis, degenerate matrix cells with clumped melanosomes and pigmentary incontinence. Mild lymphocytic infiltrative mural folliculitis was seen in the inferior segment and isthmus of the hair follicles. Hair shafts were often unpigmented and dysplastic. The large majority of infiltrating lymphocytes were CD3(+) T cells, whereas only occasional CD20(+) lymphocytes were present in the peribulbar infiltrate. Our findings confirm the diagnosis of T-cell-mediated alopecia areata in these cows. Alopecia areata appears to occur with increased frequency in the Eringer breed, but distinct predisposing factors could not be identified.

Evaluation of lymphocyte apoptosis in dogs with inflammatory bowel disease.

OBJECTIVE: To determine whether lymphocyte apoptosis in intestinal mucosae is more common in healthy dogs than dogs with inflammatory bowel disease (IBD) and whether numbers of apoptotic cells increase after successful treatment of affected dogs. ANIMALS: 8 dogs with IBD (IBD dogs) and 8 healthy control dogs. PROCEDURES: Biopsy specimens of the duodenum and colon were obtained via endoscopy from dogs with IBD before and after 10 weeks of standard treatment and compared with specimens obtained from control dogs. Expression of activated caspase 3 (Casp3), caspase-cleaved fragment p85 from poly-ADP-ribose polymerase (PARP), and B-cell leukemia/lymphoma 2 (Bcl-2) was measured in the duodenal (villous tip and base) and colonic mucosae. RESULTS: Expression of Casp3 was greater in the duodenal villous tips of control dogs, compared with expression in similar tissues from dogs with IBD before or after treatment. Despite clinical improvement of dogs with IBD, expression of Casp3 did not increase after treatment. Expression of PARP did not differ between groups at any time point. Expression of Bcl-2 was greater at all 3 tissue sites in control dogs, compared with expression at the same sites in dogs with IBD. Furthermore, Bcl-2 expression in duodenal villous tips was higher in dogs with IBD after treatment but was not higher elsewhere. In control dogs, expression patterns for all 3 markers were similar between sites (villous tip > villous base > colon). CONCLUSIONS AND CLINICAL RELEVANCE: Expression of Casp3 in lymphocytes in duodenal villous tips was significantly reduced in dogs with IBD, compared with expression in healthy dogs, but no increase was detected following successful treatment of IBD. Increased expression of Bcl-2 may be a potential marker of the success of treatment.