Successful resolution of dermatophyte mycetoma following terbinafine treatment in two cats.

Microsporum canis sensitive to itraconazole and terbinafine was isolated from two cats presented with generalized dermatophytosis and dermatophyte mycetoma. Itraconazole therapy was withdrawn through lack of efficacy in one cat (a Persian) and unacceptable adverse effects in the other (a Maine Coon). Both cats achieved clinical and mycological cure after 12-14 weeks therapy with 26-31 mg kg(-1) terbinafine every 24 h per os (PO). Clinical signs in the Maine Coon resolved completely after 7 weeks treatment. Four weeks of therapy with additional weekly washes with a 2% chlorhexidine/2% miconazole shampoo following clipping produced a 98% reduction in the Persian cat's mycetoma, which was then surgically excised. Recurrent generalized dermatophytosis in the Persian cat has been managed with pulse therapy with 26 mg kg(-1) terbinafine every 24 h PO for 1 week in every month. No underlying conditions predisposing to dermatophytosis were found in either cat despite extensive investigation. Terbinafine administration was associated with mild to moderate lethargy in the Persian cat, but no other adverse effects or changes in blood parameters were seen. To the best of the authors' knowledge this is the first report of a dermatophyte mycetoma in a Maine Coon and of successful resolution of this condition in cats following terbinafine therapy.

A comparison of adherence by four strains of Staphylococcus intermedius and Staphylococcus hominis to canine corneocytes collected from normal dogs and dogs suffering from atopic dermatitis.

The aim of this study was to compare the adherence of four strains of Staphylococcus intermedius and a single strain of Staphylococcus hominis to corneocytes from both normal dogs and dogs suffering from atopic dermatitis. Cells from the skin surface, corneocytes, were collected from 10 normal dogs and 10 dogs suffering from atopic dermatitis. Four strains of S. intermedius, three isolated from canine pyoderma skin lesions (strains A, B and C), and one isolated form from canine synovial membrane sample from a case of septic arthritis (strain D) were compared. S. hominis, which is not normally associated with canine disease, was also evaluated for its ability to adhere to canine corneocytes. S. hominis did not adhere to canine corneocytes. All four strains of S. intermedius adhered well to canine corneocytes collected from both normal and atopic dogs. All strains of S. intermedius showed statistically greater adherence to corneocytes collected from atopic dogs compared with those collected from normal dogs. It was concluded that the adherence assay employed here showed that S. hominis does not adhere to canine corneocytes, S. intermedius adheres preferentially to atopic corneocytes.

Immunoglobulin levels in Bull terriers suffering from lethal acrodermatitis.

An enzyme-linked immunosorbent assay, developed by one the authors (Huang, 1993) was used to measure immunoglobulin levels in previously stored plasma samples from eight dogs suffering from lethal acrodermatitis (LAD) and 10 normal Bull terriers. The aim of the study was to document plasma immunoglobulin levels and to determine if dogs suffering from LAD had low IgA levels. The results showed that dogs suffering from LAD had normal IgG and IgM levels but significantly lower IgA levels than the control group. This finding may in part explain the frequent occurrence of microbial infections recorded in dogs suffering from LAD.

Adherence by Staphylococcus intermedius to canine keratinocytes in atopic dermatitis.

The adherence of Staphylococcus intermedius to canine keratinocytes in normal dogs was compared to that in dogs suffering from atopic dermatitis, primary seborrhoea and bacterial pyoderma. Statistically significant greater adherence by S. intermedius to keratinocytes occurred in atopic dogs and dogs suffering from pyoderma when compared with the normal group (P < 0.01) and dogs suffering from primary seborrhoea (P < 0.05). This is similar to the results of a study of human atopic dermatitis by Cole and Silverberg (1986) who demonstrated increased adherence by S. aureus to keratinocytes from atopic dermatitis patients when compared with adherence to keratinocytes in a variety of non-atopic dermatoses. This increased adherence by pathogenic staphylococci to keratinocytes may in part explain the high incidence of staphylococcal pyoderma seen in both canine and human patients suffering from atopic dermatitis.

Malassezia and Candida infections in bull terriers with lethal acrodermatitis.

In 12 cases of lethal acrodermatitis (LAD), four sampling techniques (brush, swab, scrape and adhesive tape strip) were used to study the distribution of yeasts in various body sites and these results were compared with those from five cases of atopic dermatitis and those of 10 normal dogs. Malassezia was frequently isolated from lesional and non-lesional skin and haircoat, footpads, nails and mucous membranes from dogs with either LAD or atopic dermatitis, although, generally, more Malassezia organisms were isolated from LAD cases. In normal dogs, Malassezia was most frequently recovered from the ear canal and the perianal skin. Candida was isolated frequently from dogs with LAD, but only a single isolate of this yeast was found in the other two groups. Fungal hyphae and pseudohyphae, probably Candida albicans, could be detected in samples collected from the nails and footpads of dogs with LAD. Both Malassezia and Candida could be isolated using all four sampling techniques. The MacKenzie (toothbrush) technique and adhesive tape strip cultures proved simple methods for the semiquantitative evaluation of yeasts. The high recovery rate of Malassezia and Candida from dogs with LAD is probably related to immune dysfunction, particularly T-cell dysfunction, known to be present in these dogs. C albicans infection may in part be responsible for the pathogenic changes of the nails and footpads commonly seen in cases of LAD.

Diagnostic features, confirmation and disease progression in 28 cases of lethal acrodermatitis of bull terriers.

Lethal acrodermatitis (LAD) is a genetically determined metabolic disease of bull terriers first described in the USA in the 1980s. In this study, the largest so far reported, 28 bull terriers born in the UK were diagnosed as suffering from LAD, and the clinical findings and the progression of the disease with time are described. The main characteristics of LAD are stunting, splayed digits, eating difficulties, skin disease of the face and feet, and increased susceptibility to microbial infections. In older dogs, paronychia, nail disease and hyperkeratosis of the footpads develops, becoming severe in dogs over six months of age. A diagnosis of LAD can be strongly suspected in any bull terrier showing a combination of the aforementioned signs from an early age. Dermatohistopathological demonstration of marked parakeratotic hyperkeratosis is strongly supportive of the diagnosis of LAD and, in association with the typical clinical findings, is sufficient to confirm a diagnosis. Although many of the clinical signs and the pathology of this condition suggest zinc deficiency, the measurement of blood zinc levels as a diagnostic aid is of limited value.

Reduced in vitro adherence of Staphylococcus species to feline corneocytes compared to canine and human corneocytes.

It is apparent that in-contact humans and animals exchange commensal staphylococci. Previous in vitro studies, however, indicate that staphylococci preferentially adhere to corneocytes from host species. This study compared adherence of meticillin-sensitive and -resistant Staphylococcus aureus (MSSA/MRSA), S. intermedius, S. felis and S. hominis to feline, canine and human corneocytes acquired from 10 healthy subjects using adhesive tape discs. Adherent bacteria were counted using an image processing and analysis programme. Mean adherence of MSSA (P = 0.0009), MRSA (P = 0.0162) and S. intermedius (P = 0.0117), but not S. felis or S. hominis, to feline corneocytes was significantly lower than that to canine and human corneocytes. All the isolates had similar adherence to both human and canine corneocytes. S. felis was the most adherent species to feline corneocytes followed by S. intermedius, and then MSSA, MRSA and S. hominis. For dogs and humans, S. intermedius and S. felis were the most adherent, followed by MRSA and MSSA, and then S. hominis. These results do not reveal any preferential adherence of staphylococci to canine or human corneocytes. Poor adherence to feline corneocytes could suggest that cats are relatively resistant to pyoderma and cross-species transmission of staphylococci.

Use of ultrasound in the measurement of subcutaneous fat and prediction of total body fat in dogs.

An ultrasonographic unit (A-scan mode) has been evaluated as a noninvasive method for estimating body fat in 25 dogs. Six anatomical sites were defined and subcutaneous fat thickness was measured by means of ultrasound and histology. Total body fat was subsequently calculated in 12 dogs. There was a high correlation between histology and ultrasound for the measurement of subcutaneous fat (r = 0.81; P less than 0.001). Total body fat was successfully predicted using measurements taken with ultrasound at the lumbar area (r = 0.87; P less than 0.001). Measurements of subcutaneous fat thickness from other anatomical sites did not estimate body fat with the same accuracy. These results suggest that ultrasound can reliably measure subcutaneous fat in dogs and that these measurements, when taken from the mid lumbar area, can be used to predict total body fat.