Immunohistochemical localization of fibroblast growth factor 18 in hair follicles of healthy beagle dogs.

Increasing emphasis is being placed on the role of fibroblast growth factors (FGFs) in hair follicle cycling. In mice, expression of FGF18 mRNA peaks during the late telogen phase, leading to the hypothesis that FGF plays a role in anagen induction. There are no data on the presence of FGF18 in dogs. The main objective of this study was to identify and locate FGF18 in the canine hair follicle. The second objective was to assess potential differences in FGF18 concentration between biopsies taken in winter and summer, shoulder and flank regions, and between different sexes. Skin tissue from 10 healthy beagle dogs (three intact females, three spayed females and four intact males) was collected from the shoulder and flank. The biopsies were collected in February and August on day 0, after which the dogs were clipped and biopsies collected again from the shoulder and flank on days 1, 3, 7 and 17. Paraffin sections (4 µm thick) of the biopsies were stained with an anti-FGF18 antibody. The FGF18-positive cells were counted in the hair follicle epithelium from seven follicular units of each biopsy. Fibroblast growth factor 18 was detected as granular cytoplasmatic staining in follicles at the level of the inner root sheath, and rarely in the outer root sheath and dermal papilla. It was also detected in the apocrine glands, in arrector pili muscles and in vascular endothelial cells. There was no statistical difference in the number of FGF18-positive cells or follicles between sexes, different anatomical locations, seasons or the consecutive days of sampling.

Organic diseases mimicking acral lick dermatitis in six dogs.

Acral lick dermatitis ("lick granuloma") in dogs is often thought to have a behavioral etiology. However, other diseases may cause lesions on the distal legs, mimicking acral lick dermatitis. In this report, six dogs were presented with acral lick dermatitis-like lesions from different underlying causes-namely lymphoma, an orthopedic pin, deep pyoderma, mast cell tumor, leishmaniasis, and (presumptive) sporotrichosis.

Use of hyposensitization injections to control seasonal pruritus in a Bactrian camel (Camelus bactrianus).

A 9-yr-old, female Bactrian camel (Camelus bactrianus) developed severe pruritus in June 1993. During the next 8 yr, the camel exhibited annual episodes of pruritus and epiphora, generally beginning in June and subsiding in October of each year. These signs could usually be controlled with topical agents and fly repellents, although pruritus flare-ups were effectively controlled with intermittent injections of diphenhydramine and corticosteroids. There were no signs during the colder months. The pruritus became more severe and difficult to control when the camel reached its 18th year. Histopathologic descriptions of skin biopsies taken from several sites suggested a hypersensitivity reaction with secondary changes because of bacterial infection or corticosteroid administration (or both). An intradermal test (IDT) performed using 62 allergens regionalized to Northern California resulted in 17 positive test sites. Hyposensitization therapy was initiated using allergens chosen on the basis of exposure, availability, and the results of the IDT, using standard protocols. The clinical signs of pruritus were markedly reduced in the 2 yr after the hyposensitization injections were initiated.

Pemphigus foliaceus in the horse: a retrospective study of 20 cases.

Twenty horses with pemphigus foliaceus were seen over a period of 15 years in a veterinary medical teaching hospital. Breeds seen were seven quarterhorses, five thoroughbreds, three cross-bred horses, two Arabians and one of each of the following: standardbred, Tennessee walker and warmblood. There was no breed, age or sex predisposition. Nine were mares, ten were geldings and one was a stallion. Ages ranged from 2.5 months to 25 years, with a mean of 8.6 years. Sixteen (80%) of the pemphigus foliaceus horses first exhibited signs between September and February. There was a statistically significant more common occurrence of pemphigus foliaceus during those months. Signs in the four other horses were first noted in March, May or June. Three of those horses were < 13 months of age. Oedema (14/20) and crusts (13/20) were the most common lesions. Pain was present in 9/20 horses, pruritus in 7/20 and pyrexia in 7/20. Follow-up was available for 13 horses. Five of these horses were euthanased. In three horses the reason for euthanasia was laminitis secondary to treatment. Four horses remained lesion-free after medication was discontinued. Two horses required maintenance medication and are doing well at the time of writing.