Danny W. Scott

Feline papillomas and papillomaviruses.

Papillomaviruses (PVs) are highly species- and site-specific pathogens of stratified squamous epithelium. Although PV infections in the various Felidae are rarely reported, we identified productive infections in six cat species. PV-induced proliferative skin or mucous membrane lesions were confirmed by immunohistochemical screening for papillomavirus-specific capsid antigens. Seven monoclonal antibodies, each of which reacts with an immunodominant antigenic determinant of the bovine papillomavirus L1 gene product, revealed that feline PV capsid epitopes were conserved to various degrees. This battery of monoclonal antibodies established differential expression patterns among cutaneous and oral PVs of snow leopards and domestic cats, suggesting that they represent distinct viruses. Clinically, the lesions in all species and anatomic sites were locally extensive and frequently multiple. Histologically, the areas of epidermal hyperplasia were flat with a similarity to benign tumors induced by cutaneotropic, carcinogenic PVs in immunosuppressed human patients. Limited restriction endonuclease analyses of viral genomic DNA confirmed the variability among three viral genomes recovered from available frozen tissue. Because most previous PV isolates have been species specific, these studies suggest that at least eight different cat papillomaviruses infect the oral cavity (tentative designations: Asian lion, Panthera leo, P1PV; snow leopard, Panthera uncia, PuPV-1; bobcat, Felis rufus, FrPV; Florida panther, Felis concolor, FcPV; clouded leopard, Neofelis nebulosa, NnPV; and domestic cat, Felis domesticus, FdPV-2) or skin (domestic cat, F. domesticus, FdPV-1; and snow leopard, P. uncia, PuPV-2).

The comparative pathology of non-viral bullous skin diseases in domestic animals.

In a review of non-viral bullous skin diseases of domestic animals and a 4-year study of cases presented to the New York State College of Veterinary Medicine, we found 15 diseases: pemphigus vulgaris, pemphigus vegetans, pemphigus foliaceus, pemphigus erythematosus, bullous pemphigoid, systemic lupus erythematosus, dermatitis herpetiformis, toxic epidermal necrolysis, drug eruption, epidermolysis bullosa, epidermolysis bullosa simplex, familial acantholysis, bovine congenital porphyria, impetigo and subcorneal pustular dermatosis. The 15 diseases were placed in five categories: autoimmune, immune-mediated, hereditary, bacterial and idiopathic. A histologic classification of these disorders based on the site of blister formation and other important clinicopathologic, histologic and immunopathologic findings was developed.

Pemphigus and pemphigoid in dog and man: Comparative aspects

A review of canine pemphigus vulgaris, pemphigus vegetans, pemphigus foliaceus, pemphigus erythematosus, and bullous pemphigoid shows them to share many clinicopathologic similarities with their human counterparts. Because of their numerous analogies in clinical presentations, histopathologic and immunopathologic findings, and therapeutic results, canine and human pemphigus and pemphigoid may represent a valuable area for comparative dermatologic research.

Apparent clinical resolution of pinnal actinic keratoses and squamous cell carcinoma in a cat using topical imiquimod 5% cream.

Imiquimod is a topical immune response modifier and stimulator used in humans to treat a number of cutaneous neoplasms. This case report describes a cat with actinic keratoses and squamous cell carcinoma of the pinnae. The pinnal lesions were treated with topical 5% imiquimod three times per week. Treatment was discontinued after 82 days of therapy. Twelve weeks of topical imiquimod application resulted in clinical resolution of the pinnal lesions. Although no post-treatment biopsies were performed, there was no relapse of the pinnal lesions in 5 months of clinical follow-up. Expected side effects were limited to erythema, crusting, alopecia, and mild discomfort at the sites of application during the first 3 weeks of application. These results suggest that topical imiquimod, although unproven, might be a therapeutic option or adjunct to therapy for cats with actinic keratoses and squamous cell carcinoma, especially those cats for whom surgery and radiation therapy are not an option.

Skin diseases in the alpaca (Vicugna pacos): a literature review and retrospective analysis of 68 cases (Cornell University 1997–2006)

This retrospective study describes 68 alpacas with skin diseases investigated from 1997 through 2006 at Cornell University. During this time period, 40 of 715 (5.6%) alpacas presented to the university hospital had dermatological diseases. In addition, skin-biopsy specimens accounted for 86 of 353 (24.4%) of alpaca biopsy specimens submitted to the diagnostic laboratory, and of these 86 specimens, follow-up was available for 28 cases. The following diseases were most common: bacterial infections (22%); neoplasms, cysts and hamartomas (19%); presumed immunological disorders (12%); and ectoparasitisms (10%). Conditions described for the first time included intertrigo, collagen and hair follicle hamartomas, lymphoma, hybrid follicular cysts, melanocytoma, anagen defluxion, telogen defluxion, presumed insect-bite hypersensitivity, ichthyosis, and possible hereditary bilateral aural haematomas and chondritis. The results of the retrospective study are compared and contrasted with the results of a literature review.

Focal necrotizing panniculitis and vascular necrosis in rats given subcutaneous injections of cocaine hydrochloride

Subcutaneous injections of cocaine hydrochloride in sterile physiological saline were administered to rats at a dosage of 20 or 40 mg. kg−1. Resultant skin lesions included focal areas of alopecia (within 1 to 2 days) which progressed to necrosis (within 2 to 7 days). Histologically, the skin lesions were characterized by necrotizing panniculitis and vascular necrosis, with only small numbers of inflammatory cells. The lesions may be ischemic in nature, and associated with cytotoxic properties of cocaine.

Feline dermatology at Cornell University: 1407 cases (1988–2003):

Medical records of 1407 cats with dermatologic diagnoses made at Cornell University teaching hospital from 1988 to 2003 were tabulated. We expressed the diagnoses as counts, percentages of the cats with dermatologic disease (1407) and percentages of all cats seen at the university hospital (22,135) during the same period. A total of 1887 diagnoses were made in the 1407 cats. We compared the age, sex and breed group of our cases with all those 22,135 cats in (‘1-by-c’) χ2 tests in which the hospital population was considered a standard (rather than a ‘sample’). The 10 most common dermatoses, their counts, and the proportions of dermatologic diagnoses and of the total cat population that the cats with these dermatoses represented were: allergy (298; 15.8%; 1.35%), atopic dermatitis (194; 10.3%; 0.88%), bacterial folliculitis/furunculosis (189; 10.0%; 0.85%), otodectic mange (115; 6.1%; 0.52%), flea infestation (99; 5.2%; 0.45%), feline acne (74; 3.9%; 0.33%), flea-bite allergy (70; 3.7%; 0.32%), cutaneous adverse drug reaction (56; 3.0%; 0.25%), idiopathic eosinophilic-granuloma complex (55; 2.9%; 0.25%) and abscess (51; 2.7%; 0.23%). Allergies of all types, combined, accounted for 32.7% of all the feline dermatoses. Relative to the standard of the total hospital population, cats <2 years old and females (both intact and spayed) were significantly under-represented (all P≤0.001) in the dermatologic case series. In contrast, Himalayans (compared with domestic short- or longhair, Persian, Siamese and other breeds) and males (both intact and neutered) were significantly over-represented (all P ≤0.001).

Infiltrative lymphocytic mural folliculitis: A histopathological reaction pattern in skin-biopsy specimens from cats with allergic skin disease

This study was conducted to determine the prevalence of infiltrative lymphocytic mural folliculitis (ILMF) in skin-biopsy specimens from 354 cats with various inflammatory dermatoses and from 33 cats with normal skin. Although ILMF was present in 33/47 dermatoses evaluated, the prevalence of ILMF in allergic dermatoses (116/172 cats; 67%) was significantly greater than that in non-allergic dermatoses (61/182 cats; 33%). Cats with allergic dermatoses had a 4.1 times greater odds of having ILMF than cats with non-allergic dermatoses. ILMF was not observed in any of the normal skin specimens.

Pemphigus in domestic animals

Abstract Pemphigus has been recognized in humans for many years. The occurrence of pemphigus in domestic animals is a much more recent observation. In the dog, pemphigus vulgaris was first reported in 1975, 1,2 pemphigus vegetans in 1977, 3 pemphigus foliaceus in 1977, 4 and pemphigus erythematosus in 1980. 5 In the cat, pemphigus vulgaris, pemphigus foliaceus, and pemphigus erythematosus were reported in 1980. 5,6 Equine pemphigus foliaceus was reported in 1981. 7 The purpose of this article is to review pemphigus in domestic animals, compare the diseases with their human counterparts, and alert the physician to an exciting area for comparative dermatologic research.

The microanatomy of healthy skin from alpacas (Vicugna pacos).

The microanatomy of healthy skin from 12 different body sites was investigated in 14 alpacas (Vicugna pacos). The microanatomy of alpaca skin is typical of domestic animal skin in general, and closely resembles that from llamas.