An unresponsive progressive pustular and crusting dermatitis with acantholysis in nine cats.

BACKGROUND: Between 2000 and 2012, nine cats were examined with a visually distinctive, progressive crusting dermatitis that was poorly responsive to all attempted therapies. OBJECTIVES: Documentation of clinical and histopathological findings of this disease. ANIMALS: Nine privately owned cats. METHODS: Retrospective study. RESULTS: Eight neutered males and one (presumably spayed) female ranging in age from two to eight years, presented for a progressive, well-demarcated, crusting dermatitis with variable pruritus of 1.5 months to five years duration. All cats lived in northern California, USA; seven lived within a 30 mile radius. Two males were littermates. Histopathological investigation showed both parakeratotic and orthokeratotic crusts, intraepidermal pustules and superficial folliculitis with rare to frequent acantholytic cells. Bacterial and fungal cultures were performed in six cats: meticillin-susceptible Staphylococcus pseudintermedius was isolated in three cats, two colonies of Trichophyton terrestre and three of Malassezia pachydermatis were isolated from one cat each. Treatment with various antibiotics, antifungal and a variety of immunosuppressive medications did not alter the progressive nature of the skin disease. CONCLUSIONS AND CLINICAL IMPORTANCE: The described disease shares some clinical and histopathological features with pemphigus foliaceus, but the lack of response to treatment, its progressive nature and the possible relatedness of some of the cats set it apart. The aetiology of this acantholytic dermatitis remains unknown.

Skin diseases in pet rabbits: a retrospective study of 334 cases seen at the University of California at Davis, USA (1984-2004).

BACKGROUND: Rabbits are growing in popularity as companion animals, and dermatology problems are often the presenting complaint when seeing a veterinarian. HYPOTHESIS/OBJECTIVES: To document skin diseases and their prevalence in pet domestic rabbits (Oryctolagus cuniculus) in northern California, USA; to investigate predilections for breed, age or sex for the most common conditions over a 20 year period. ANIMALS: Three hundred and thirty-four pet rabbits from the overall hospital population met inclusion criteria. METHODS: A retrospective study was carried out by searching the computerized medical records of rabbits seen at the Veterinary Medical Teaching Hospital (VMTH) from 1 January 1984 to 31 December 2004 using key words relevant to dermatology. RESULTS: Twenty-nine per cent of pet rabbits seen at the VMTH had skin disease. Lop-eared rabbits were over-represented, whereas mixed-breed rabbits and castrated males were under-represented in the dermatology caseload compared with the hospital population. Pododermatitis was the most common skin disease; abscesses, alopecia, otitis externa and ectoparasites also were common. Several species of bacteria other than Pasteurella spp. were isolated from abscesses. Despite the frequent mention of myxomatosis and venereal spirochetosis in the rabbit literature, few cases (three and two, respectively) were diagnosed. Castrated males were 3.7 times more likely to present with alopecia than intact males; rabbits <1 year of age were 3.6 times more likely to present with Psoroptes infestation/otitis than adult rabbits. CONCLUSIONS AND CLINICAL IMPORTANCE: Cutaneous conditions in pet rabbits in the USA are common. Bacterial culture should be performed and antibiotic susceptibility determined in all rabbits with abscesses, particularly those not responding to typical anti-Pasteurella antibiotics.

Evaluation of the clinical efficacy of pradofloxacin tablets for the treatment of canine pyoderma.

A third-generation fluoroquinolone, pradofloxacin (PRA), is currently being developed to treat bacterial infections in dogs. The purpose of this study was to assess the clinical efficacy in 20 dogs affected with superficial and deep pyoderma. An initial aerobic skin culture was performed in dogs with superficial pyoderma; aerobic/anaerobic tissue culture was performed in dogs with deep pyoderma; and skin cytology and biopsies were obtained from all dogs. Pradofloxacin (approximately 3 mg/kg per os [PO]) was administered daily to all dogs. Clinical efficacy was recorded at 4 weeks for dogs with superficial pyoderma and at 3 and 6 weeks for dogs with deep pyoderma. At a mean dosage of 3.7 mg/kg PO once daily, PRA treatment resulted in an excellent to good clinical response within 3 to 6 weeks for all 20 dogs with superficial and deep pyoderma.

Sporotrichosis: a retrospective evaluation of 23 cases seen in northern California (1987-2007).

Sporotrichosis is an uncommon to rare cutaneous and subcutaneous mycosis of animals and humans caused by the dimorphic fungus Sporothrix schenckii. Twenty-three mammalian cases of sporotrichosis examined between 1987 and 2007 at the University of California, Davis - Veterinary Medical Teaching Hospital, were retrospectively evaluated with regard to the historical, clinical, diagnostic and treatment findings. Cats were the most common species affected (n = 14). In addition, sporotrichosis was diagnosed in four dogs, four horses and a donkey. Six of 23 cases were diagnosed with the localized cutaneous form of sporotrichosis (four cats, one dog, one horse), 10 with the cutaneous-lymphatic form (four cats, two dogs, three horses and a donkey), and seven with the disseminated form (six cats, one dog). Two of 23 cases did not have skin lesions at the time of diagnosis (one cat, one dog). The most common mode of diagnosis was demonstration of S. schenckii on histopathological evaluation of tissue. In contrast with most previously described sporotrichosis infections in cats, few to no fungal organisms were seen in histopathological samples (haematoxylin and eosin and special stains) in five of the 14 cats. Treatments received included itraconazole (12 cats, one dog), ketoconazole (three dogs), fluconazole (one cat, one donkey), sodium iodide (four horses, one cat) and potassium iodide (one cat, one horse, one donkey). The prognosis for successful treatment was good in all species. Fluconazole was successful in inducing resolution of the cutaneous lesions and controlling the infection in one cat with disseminated sporotrichosis.

Cutaneous vasculitis in equines: a retrospective study of 72 cases.

Cutaneous vasculitis was identified by histopathological findings in 72 equines. The most frequent clinical findings were crusts/scales and oedema of the legs with the most common underlying disease being photo-aggravated dermatitis. Common laboratory findings were anaemia, neutrophilia, hyperglycaemia and hyperglobulinaemia. Histopathological patterns were most commonly cell-poor and lymphocytic/histiocytic. While statistically supported treatment recommendations could not be made due to the large numbers of confounding factors, trimethoprim-sulfa antibiotics, corticosteroids, and/or resolution or control of the underlying disease process were the most common treatment modalities.

Clinical and pathological findings in a HERDA-affected foal for 1.5 years of life.

A Quarter horse filly bred from two horses affected with HERDA (hereditary equine regional dermal asthenia) was observed clinically and its skin histologically for the 1.5 years of its life. Severe signs of the disease did not manifest until 1.5 years of age, and were not temporally related to saddling. Histological comparison to an age-, breed- and sex-matched control did not show any consistent diagnostic features. Monitoring of the proband substantiated previous reports of (i) the autosomal recessive nature of the disease, (ii) mares affected with HERDA being able to foal without damage to the skin or reproductive tract, (iii) HERDA foals appearing phenotypically normal throughout the first year of life, and (iv) demonstrated that histological interpretation of skin specimens from grossly normal skin may be insufficient to differentiate HERDA-affected horses from controls.

A retrospective study of cutaneous equine sarcoidosis and its potential infectious aetiological agents.

Nine horses from ages 5 to 21 years were diagnosed with cutaneous equine sarcoidosis (ES) over an 18-year period. In addition to skin, the lungs were frequently involved, with other organ systems affected less commonly. A predisposition for thoroughbreds and geldings was noted. Cutaneous lesions and signs included crusts, scales, alopecia and pruritus. These were found at various sites, particularly the legs/thighs/elbows, thorax, neck, face and ventral abdomen. Three horses were euthanized shortly after hospitalization; others survived as long as 12 years. Histopathologic stains, immunohistochemistry and polymerase chain reaction assays on paraffin-embedded cutaneous specimens from eight horses for Mycobacterium spp., Coccidioides immitis, Cryptococcus neoformans, Corynebacterium pseudotuberculosis, and Borrelia burgdorferi were all negative. The aetiology of ES is unlikely microbial and continues to be a diagnosis of exclusion. ES, when limited to the skin, is associated with a good prognosis, with either partial or complete response to glucocorticoid therapy in all the surviving horses.

Evaluation of aerobic bacteriologic culture of epidermal collarette specimens in dogs with superficial pyoderma.

OBJECTIVE: To evaluate a method of aerobic bacteriologic culture of epidermal collarette specimens from dogs with superficial pyoderma and compare results with those for aerobic bacteriologic culture of abdominal skin specimens in healthy dogs. DESIGN: Prospective study. ANIMALS: 22 dogs with epidermal collarettes and 24 healthy dogs. PROCEDURE: Dry sterile cotton swabs were rolled across epidermal collarettes or hairless areas of abdominal skin in healthy dogs and submitted for aerobic bacteriologic culture. Hemolytic colonies of gram-positive-staining cocci were tested for catalase production, and if results were positive, a coagulase test was performed. Colonies with coagulase activity were tested for the ability to ferment mannitol. Antimicrobial susceptibility testing was performed on all Staphylococcus spp that were isolated. RESULTS: S. intermedius was isolated from collarettes in 18 of 22 dogs with superficial pyoderma but not from healthy dogs. Estimated sensitivity and specificity of the culture method were 81.8% and 100%, respectively. There were no significant differences in the ability to culture S. intermedius, the number of S. intermedius isolates without resistance to antimicrobials, and the number of S. intermedius isolates resistant to penicillin G when comparing dogs with superficial pyoderma for the first time and dogs with recurrent pyoderma, dogs that did or did not receive concurrent antimicrobials, and dogs with and without underlying allergic disease. CONCLUSIONS AND CLINICAL RELEVANCE: Bacteriologic culture of epidermal collarette specimens was a simple and reliable method for identification of S. intermedius in dogs with superficial pyoderma, regardless of history of pyoderma or current antimicrobial use.

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.

Hereditary equine regional dermal asthenia ("hyperelastosis cutis") in 50 horses: clinical, histological, immunohistological and ultrastructural findings.

Data on fifty horses with hereditary equine regional dermal asthenia (HERDA; "hyperelastosis cutis") were collected on clinical, histopathological, ultrastructural and immunohistological findings. All horses were Quarter horses or of Quarter horse ancestry. Pedigree evaluation strongly supported an autosomal recessive mode of inheritance. The most common lesions were seromas/haematomas, open wounds, sloughing skin, and loose, easily tented skin that did not return to its initial position. Definitive diagnosis could not be made via histopathology, although the presence of tightly grouped thin and shortened collagen fibres arranged in clusters in the deep dermis was suggestive of the disease. Trichrome, acid orcein-Giemsa and immunohistochemical stains for collagens I and III showed no consistent abnormalities compared to control horses; an increase in elastic fibres was not a consistent finding. Electron microscopy showed no abnormalities in the periodicity of the collagen bundles; neither orientation nor variation of cross-section diameter of the collagen fibrils differentiated control from affected horses. The diagnosis of HERDA relies on clinical presentation, but may be supported by suggestive (although not pathognomonic) histopathological lesions.

Putative drug-related pemphigus foliaceus in four dogs.

Four dogs developed cutaneous lesions following the administration of various antibiotics. Histopathology of the lesions was compatible with pemphigus foliaceus, although apoptotic cells suggestive of erythema multiforme were seen in two cases. In two dogs the lesions resolved after 7.5-8.5 months of immune-suppressive treatment. No recurrence was seen during the follow-up period (3 and 4.5 years). The lesions in the other two dogs resolved within 3 weeks to 3 months following discontinuation of the antibiotic. No recurrence of clinical signs occurred during the follow-up period (1 and 4 years, respectively).

Antihistamines in the management of canine atopic dermatitis: a retrospective study of 171 dogs (1992-1998).

Antihistamines were prescribed for 178 of 271 dogs with a diagnosis of atopic dermatitis at the Veterinary Medical Teaching Hospital of the University of California, Davis from 1992 to 1998. Fifty-four percent of 166 dogs given antihistamines responded favorably to these treatments, with 27% of the responses rated as good and 27% rated as moderate. Diphenhydramine and hydroxyzine were the most commonly used antihistamines and were the most frequently effective. Chlorpheniramine and clemastine were administered less frequently and had much lower positive response rates. Responses to antihistamines as a group were significantly better in dogs having onset of clinical signs at younger ages (odds ratios for 1-year increase in age = 0.72, 95% confidence interval = 0.57 to 0.91, P =.005).

Canine atopic dermatitis: a retrospective study of 266 cases examined at the University of California, Davis, 1992-1998. Part I. Clinical features and allergy testing results.

The medical records of 266 dogs diagnosed as having atopic dermatitis were reviewed. Statistical data were evaluated referable to breed predilections, clinical signs and positive reactions to allergens. Positive reactions were most common to house dust mites (more common with clinical signs in the fall) followed by moulds (more common with clinical signs in the fall and spring). Dogs with positive reactions to moulds, trees or cultivated plants were more likely to have skin and ear yeast infections. Dogs with positive reactions to cultivated plants were more likely to have otitis externa and pedal lesions. Positive reactions to house dust were more common in dogs with early onset of signs and in those tested early in the disease. Dogs had more positive reactions to weeds when allergy tests were performed in the summer and fall. Positive reactions to flea antigen were highly correlated with the clinical diagnosis of flea allergy dermatitis.

Canine atopic dermatitis: a retrospective study of 169 cases examined at the University of California, Davis, 1992-1998. Part II. Response to hyposensitization.

One hundred and sixty-nine dogs were diagnosed with atopic dermatitis, and treated with hyposensitization for at least 1 year based on the results of either intradermal skin tests (IDST) or enzyme-linked immunosorbant serum assays (ELISA). Excellent (i.e. hyposensitization alone controlled clinical signs), good (> 50% improvement), moderate (< 50% improvement) and no (clinical signs were unchanged) responses were seen in 19.5, 32.5, 20.1 and 27.8%, respectively. Age of onset, age when treatment was initiated or the duration of clinical signs had no influence on response to hyposensitization. Dogs having concurrent flea allergy dermatitis were statistically more likely to respond better than dogs with concurrent food allergies. Although not statistically significant, there were trends for Golden Retriever and male dogs to respond better than other breeds and female dogs, respectively. Dogs having more than 21 positive reactions in allergy tests and treated with more than 21 allergens had lower response scores, and a longer time course before achieving beneficial response. Lower response scores were seen in dogs having positive reactions to cultivated plants, grasses, trees or insects. There was no difference in response to hyposensitization whether based on IDST or ELISA results.

Isolation of fungal flora from the hair coats of shelter cats in the Pacific coastal USA.

Two-hundred shelter cats from the Pacific western coastal USA were sampled in four different geographical regions to determine the fungal organisms most commonly found on the hair coat and the prevalence of these organisms. Data on the cats' health, age, hair coat length, gender, and geographical location were collected and analysed. The overall prevalence of dermatophytosis was 5.5% (11 of 200 cats), with Microsporum canis isolated in 90.9% (10 of 11) of the samples from positive cats. This was a lower isolation rate or prevalence of dermatophytes than previous studies conducted on shelter cats in other regions of the USA. Ten of 11 of the cats were lesion free (either subclinical infection or mechanical carriage). Cats in the Los Angeles, California area (P = 0.001) and neutered male cats (P = 0.047) had a higher prevalence of a positive dermatophyte culture. The numbers and types of saprophytes isolated from cats in this study were found to be consistent with previous feline reports in the USA and with an equine study previously conducted in this area.

The histology of normal llama skin.

Skin biopsy specimens of normal llama skin were examined histologically. Adnexal structures similar to those of most other domestic mammals included epitrichial sweat glands, sebaceous glands and arrector pili muscles. Unique features of normal llama skin included a very thick dermis with marked differences between superficial and deep dermis, prominent cutaneous vascular plexuses, unidentified cells with eosinophilic granules within the adventitia of the vascular plexuses, both simple and compound hair follicles, 'metatarsal glands', 'interdigital glands', footpad glands and the absence of eyelid tarsal glands.

Multiple skin tumours in a Doberman Pinscher with colour dilution alopecia.

Abstract An 11-year-old Doberman Pinscher with clinical and histological skin features consistent with colour dilution alopecia had a long history of skin disease. The animal had hundreds of papules affecting the 'blue' haired áreas of the hair coat. The predominant skin lésions included keratinizing infundibular cysts, keratin horns, perifollicular dermatitis, and sebaceous hyperplasia; these lésions were often accompanied by fürunculosis and suppurative panniculitis. Over a 9-month period, 32 lésions were examined histologically, which included two lipomas, one infiltrative lipoma, one squamous papilloma, two mast cell tumours, four cavernous haemangiomas, one haemangiosarcoma, and three melanomas. It is unknown at present whether the colour dilution phenotype confers increased risk for tumours of the skin and or subcutaneous tissues. Résumé- Un doberman de 11 ans avec des manifestations cutanées cliniques et histologiques compatibles avec le díagnostic d'alopécie des couleurs diluées avait une longue histoire de problèmes cutanés. L'animal présentait des centaines de papules affectant les zones de couleur bleue. Les lésions cutanées prédominantes consistaient en kystes infundibulaires kératinisants, cornes cutanées, dermatite périfolliculaire et hyperplasie sébacée; ces lésions s'accompagnaient souvent de füronculose et de panniculite suppurative. Sur une période de 9 mois, 32 lésions ont fait l'objet d'un examen histologique, dont deux lipomes, un lipome infiltrant, un papillome, deux mastocytomes, quatre hémangiomes caverneux, un hémangiosarcome, et trois mélanomes. On ne sait actuellement pas si le phénotype couleur diluée constitue un facteur de risque accru pour les tumeurs de la peau et des tissus sous cutanés. [Madewell, B. R., Ihrke, P. J., Griffey, S. M. Multiple skin tumours in a Doberman Pinscher with colour dilution alopecia. (Tumeurs cutanées multiples chez un doberman présentant une alopécie des couleurs diluées.) Veterinary Dermatology 1997; 8: 59-62.] Resumen Un doberman pinscher de 11 años con caracteristicas clinicas e histológicas compatibles con alopecia de color diluido tenia una larga historia de enfermedad cutanea. El animal presentaba centenares de pápulas afectando las áreas de pelo "azul". Las lesiones prédominantes incluian quistes infundibulares queratinizados, cuernos de queratina, dermatitis perifolicular e hiperplasia sebácea; estas lesiones se acompañaban de fürunculosis y paniculitis supurativa. Durante un periodo de 9 meses, 32 lesiones fueron examinadas histológicamente, incluyendo 2 lipomas, un lipoma infiltrativo, un papiloma escamoso, dos mastocitomas, cuatro hemangiomas cavernosos, un hemangiosarcoma y tres melanomas. Se desconoce aún si el fenotipo de color diluido aumenta el riesgo para la aparición de tumores en tejidos cutáneos y subcutáneos. [Madewell, B. R., Ihrke, P. J., Griffey, S. M. Multiple skin tumours in a Doberman Pinscher with colour dilution alopecia. (Multiples tumores cutáneos en un Doberman Pinscher con alopecia de color diluido.) Veterinary Dermatology 1997; 8: 59-62.] Zusammenfassung- Ein elfjähriger Dobermann mit klinischen und histologischen Befunden, die bei Farbmutantenalopezie auftreten, wies eine lange Vorgeschichte mit Hautkrankheiten auf. Das Tier zeigte Hunderte von Papeln, die die "blau" behaarten Bezirke des Felles betrafen. Die vorherrschenden Hautveränderungen bestanden in keratinisierenden infundibulären Zysten, Keratinhörnern, perifollikulärer Dermatitis und Talgdrüsenhyperplasie; diese Veränderungen wurden oft von Furunkulose und eitriger Pannikulitis begleitet. Über eine Zeitspanne von 9 Monaten wurden 32 Veränderungen histologisch untersucht, wovon zwei in Lipomen bestanden, eine in einem infiltrativen Lipom, eine in einem squamösen Papillom, zwei in Mastzelltumoren, vier in kavernösen Hämangiomen, eine in einem Hämangiosarkom und drei in Melanomen. Es ist zur Zeit nicht bekannt, ob der Phänotyp mit der Farbverdünnung mit einem erhöhten Risiko für Tumoren der Haut und/oder des subkutanen Gewebes einhergeht. [Madewell, B. R., Ihrke, P. J., Griffey, S. M. Multiple skin tumours in a Doberman Pinscher with colour dilution alopecia. (Multiple Hauttumoren bei einem Dobermann mit Farbmutantenalopezie.) Veterinary Dermatology 1997; 8: 59-62.].