P‐13 Dermatophytosis in domestic cats: treatment with lufenuron

Preliminary studies showed that lufenuron inhibits chitin synthesis, a dermatophyte cell wall constituent, and may be effective in the treatment of dermatophytosis. Our purpose was to evaluate the efficacy of lufenuron in the treatment of feline dermatophytosis. Forty‐six cats (Persians and mixed‐breed cats from 1‐month to 4‐years old) naturally infected with Microsporumcanis were included in this study. Fifteen cats were treated isolated in cages in the veterinary hospital and 31 were treated in their home environment (some with access to the outdoors). Dermatophyte skin lesions were seen in 29 animals while 17 other cats were asymptomatic carriers. Wood's lamp, direct microscopic examination of hairs, fungal culture and skin biopsies were used for the diagnosis. Affected cats and all in‐contact animals received lufenuron at a dose of 120 mg/kg every 21 days for four treatments. Of the 29 symptomatic cats treated with lufenuron, 70% recovered within 21 days and 28% within 42 days of initiation of therapy. One cat had only partial recovery and another was euthanized. Negative fungal culture was recorded only after the fourth dose of lufenuron in 98% of affected cats and 100% of asymptomatic carriers. There was no difference in clinical response to lufenuron between the cats treated in their home environment and those treated in the veterinary hospital. Side effects were not observed, thus the drug proved to be safe and effective for the treatment of dermatophytosis. Funding: Novartis.     

P‐36 Juvenile idiopathic nasal scaling in three Bengal cats

Affected cats were three Bengals, one male and two females, whose age at onset of lesions ranged from 13‐ to 20‐weeks old. Nasal planum scaling progressed to thick crusting, consequent exfoliation and exposure of underlying erosions. No signs of pruritus or pain were present but mild respiratory signs were noticed. In all cats, haematology and biochemistry were normal, they were FIV and FeLV negative, PCR for herpesvirus, calicivirus and Chlamydia were negative, and viral isolation for calicivirus and herpesvirus was negative. Wood's lamp examination was negative, as were bacterial and fungal cultures. Cytology showed exfoliating keratinocytes. A skin biopsy taken from one case showed no significant changes. Biopsies from the nasal planum of four dead cats with nondermatological conditions (controls) were collected for comparative studies. Morphometry to record the percentage of the granular layer (GL) and stratum corneum (SC) on the total thickness of the epidermis of the nasal planum was performed. The GL and SC accounted for 10.2 and 21.7% of the epidermal thickness in the affected cat, compared to 18.3 and 20.2%, respectively, in the controls. A significant reduction (P < 0.02) of the SC thickness was detected in the affected cat compared to controls. No treatment was instituted as all cats underwent complete (two cats) or nearly complete (one cat) resolution. The reported cases share the same breed, age at onset, type of lesions and a similar outcome. A reduction of the SC thickness in one of the affected cats was recorded. Therefore, an underlying congenital condition is suspected that manifests with high epidermal cell turnover and normal keratinization. Funding: Self‐funded.     

P‐62 Dermal and subcutaneous extraskeletal osteosarcomas in eight dogs,two cats,and one ferret

Osteosarcoma is a malignant mesenchymal neoplasm characterized by the formation of osteoid tissue. It is the most frequent primary bone tumour in dogs, accounting for nearly 80–85% of all reported long bone appendicular osteosarcomas. Conversely, in cats and other species, osteosarcoma is rare at any site. Extraskeletal osteosarcoma (EOS) is a malignant, osteoid‐producing neoplasm without primary periosteal or bone involvement. These tumours have been described less frequently and occur mainly in the mammary glands of female dogs. Case material was obtained from biopsy records of the Pathology Service at the Veterinary School, Universidad Nacional. The diagnosis of these tumours was based on the absence of clinical, radiological, or pathological evidence of primary bone or glandular involvement. Samples were processed for histopathological examination and stained with H&E. In two cases, immunohistochemistry was performed. Eleven cases were diagnosed with EOS located in two histological locations. The dermal group consisted of three female dogs (two Rottweillers and one Fila Brasileiro), one male German shepherd (mean age of dogs: 5.5 years), two female cats (mixed‐breed and Siamese) of 5 and 11 years of age, respectively, and one 4‐year‐old female ferret. The subcutaneous group consisted of four dogs, two female pit bull terriers and two male dogs (boxer and mixed‐breed), with a mean age of 5 years. The subcutaneous EOS tumours were more aggressive. Three dogs were euthanized due to lung metastasis and the remaining dog was lost to follow‐up. Funding: Self‐funded.     

P‐59 Three cases of opportunistic dermatoses associated with internal diseases in cats

Opportunistic dermatoses can occur in case of immunosuppressive diseases. The first case was a 12‐year‐old domestic short‐haired cat suffering from diabetes with a phaeohyphomycosis due to Scytalidium spp.associated with cutaneous hemangiosarcoma. A painless and ulcerated nodule was observed on a digit with fistulous tracts over the metatarsal joint. Histopathological examination of the nodule revealed a hemangiosarcoma in which brownish fungal colonies were found. Itraconazole (5 mg/kg twice daily), then amputation, allowed 12 months of survival (pulmonary metastases). The second case concerned a 13‐year‐old Siamese cat with cheyletiellosisassociated with spontaneous Cushing's disease and diabetes mellitus. This cat exhibited scales and miliary dermatitis on the trunk associated with polyuria, polydipsia and a pot‐belly. Acetate tape impression showed Cheyletiella blakei mites and eggs. Blood analysis revealed diabetes mellitus and spontaneous hyperadrenocorticism. The owner refused treatment. The third case was a 14‐year‐old domestic short‐haired cat with generalized demodicosis associated with iatrogenic Cushing's disease and diabetes mellitus. Long‐acting glucocorticoids had been used for treatment of plasma cell stomatitis for 5 years. This cat exhibited erythema, scales, self‐induced alopecia, thin skin and moderate pruritus associated with polyuria and polydipsia. Cutaneous lesions principally developed on the abdomen and flanks. Skin scrapings and trichogram showed numerous Demodex cati mites. Routine blood work demonstrated diabetes mellitus and iatrogenic Cushing's disease. Treatment was based on insulin therapy, milbemycin oxime (1 mg/kg once daily) and chlorambucil (0.2 mg/kg once daily). The demodicosis was cured after 4 months, but the cat died of cutaneous and ocular herpesvirus infection 10 months later. Funding: Self‐funded.     

P‐20 Clinical,cytopathological and histopathological evaluation of sporotrichosis in experimentally infected cats

The purpose of this study was to evaluate the clinicopathological aspects of experimental sporotrichosis in cats and compare the sensitivity of cytopathology, histopathology and culture as diagnostic tools in different phases of the infection. Twenty adult, mixed‐breed cats (10 males and 10 females) were inoculated subcutaneously with 10⁶ fungal microorganisms. Clinical examination was performed weekly. Cytopathologic, histopathologic and culture examinations were performed at 15, 30 and 60 days postinoculation. Culture of multiple organs was performed after euthanasia at 30 (10 cats) and 60 (10 cats) days postinoculation. Friedman parametric and nonparametric statistical analysis were applied to the results. The nodular, tumoral and necrotic lesionsprogressed significantly until day 30 postinoculation, and partial spontaneous regression occurred at day 60, particularly in males. An intense inflammatory pyogranulatomous and lymphocytic infiltrate with rare giant cells and sparse fibrosis associated with numerous, pleomorphic, intra‐ and extracellular fungal cells were observed on day 30. These findings gradually decreased by day 60. Despite the inflammatory granuloma associated with feline sporotrichosis, a tendency for dissemination was observed, with fungal isolation in the lymph nodes, spleen and liver at the 30 and 60 days postinoculation. No significant differences were observed between cytopathology, histopathology and fungal culture during the different phases of the disease. Therefore, cytological examination was considered a simple, rapid and inexpensive diagnostic method at all stages of this disease. Funding: Self‐funded.     

P‐87 Alopecia in two guinea pigs due to hypopodes of Acarus farris

Mites are frequent agents of skin diseases in veterinary dermatology, particularly in rodents. The authors report an original case of infestation in two guinea pigs of the same household. Two adult guinea pigs were presented with a 3‐month history of alopecia, matted hair, erythema, scales and mild pruritus. The first guinea pig showed almost complete truncal alopecia with mild scaling, whereas the other one had only recently developed mild alopecia of the abdomen and mild pruritus. Numerous live, long‐legged mites were present both in adhesive tape and skin scrapings. Mycology (Wood's lamp and DTM agar culture) was negative. Histopathological examination of a skin biopsy did not reveal any significant inflammatory disease and morphological changes were limited to hair follicles in the telogen phase. Mites were identified as hypopodes of Acarus farris (Acaridae), but no adult stages were present. Hypopodes were also found in the hay. Control was obtained with acaricidal treatment with Phoxim 0.05% once weekly for 4 weeks, and the elimination of contaminated hay. The lesions and the alopecia resolved rapidly. Hypopodes are additional nymphal stages of some mites of the suborder Astigmata. They develop for dispersing or dormancy under disadvantageous conditions. They can be active or inert, and some can be phoretic on the skin surface or intrafollicular. Although nonparasitic, they may cause dermatitis. Acarus farris have been rarely mentioned in the literature as a cause of dermatitis. This condition could be underdiagnosed or misdiagnosed in veterinary dermatology. Funding: Self‐funded.     

P‐45 Treatment of allergic feline asthma with allergen avoidance and specific immunotherapy: 20 cats

Twenty cats presented with respiratory signs identified as asthma lasting for several months or years. The episodes of acute coughing and dyspnea were severe, requiring frequent glucocorticoid therapy. An allergic diagnosis was proposed in order to identify the putative allergens involved and to try specific therapy. Three cats developed diabetes mellitus secondary to glucocorticoid treatments. Two of them could not be tested and were given inhalant therapy with bronchodilators and glucocorticoids several times during the day and night. Intradermal tests were performed in 18 cats using 42 aeroallergens. Three tests were negative, even after a second test. Inhalant therapy was prescribed for three cats. Fifteen cats showed positive intradermal test reactions to house dust mites, storage mites and less frequently, pollens. When intradermal test results were positive for storage mites or cockroach, elimination of dried food was first recommended. This was sufficient for remission of the respiratory signs in three cats. Specific immunotherapy was prescribed for the other 12 cats. At the initiation of immunotherapy, all cats were treated with inhaled medications. After 6–9 months, immunotherapy was effective in controlling clinical signs of asthma without any other symptomatic treatment in eight cats. Four cats still required inhaled salbutamol and beclometasone two to three times weekly, instead of two to three times daily. This study demonstrates the role of allergenic stimuli in feline asthma and the advantage of specific immunotherapy as a long‐term treatment. Funding: Self‐funded.     

P‐56 Evaluation of the association between Giardia infection and pruritic skin disease in dogs

Intestinal parasites have been anecdotally associated with pruritus in dogs. A relationship was proposed when the elimination of a specific parasite resolved the pruritus, and re‐infection with a parasite caused the pruritus to recur. Ascarids, coccidia, hookworms, tapeworms and whipworms have all been incriminated. Recent reports in the human and veterinary literature have suggested that there may be a relationship between Giardia infection and the development of pruritus and other allergic signs. In order to determine if there is an association between infection with Giardia and pruritus in dogs, faecal samples were collected from 71 pruritic dogs and 101 clinically normal dogs. Three faecal samples from each animal were analysed using a zinc‐sulphate concentration technique for the presence of Giardia cysts, and one randomly selected faecal sample from each dog was analysed with an ELISA for Giardia‐specific antigen. Ten of 101 dogs (9.9%) in the clinically normal group tested positive with the ELISA, and Giardia cysts were detected in the faeces of seven of these antigen‐positive dogs. No Giardia cysts were found in the dogs that tested negative with the ELISA. None of the dogs in the pruritic group tested positive for Giardia by either method. The results indicated a negative association between Giardia infection and pruritic skin disease (P = 0.006). Cephalexin was commonly used in the pruritic group, but not in the control group, and may therefore be an explanatory variable. Funding: Ontario Veterinary College Pet Trust.     

P‐10 Comparison of carpet and toothbrush methods for the detection of asymptomatic carriage of dermatophytes in cats

Diagnosis of Microsporum canis infection is a challenge in cats with suspected asymptomatic carriage. The aim of this study was to compare the carpet method and the toothbrush method of sample collection for dermatophyte culture. The study was conducted on apparently healthy cats in a chronically infected cattery. Sampling was performed with both a sterilized piece of carpet and a toothbrush applied to the entire body surface. Samples were inoculated on Sabouraud's media (with chloramphenicol and cycloheximide). Multiple (6) applications with the toothbrush were necessary to obtain a similar surface area of inoculation. Cultures were incubated at 27°C, then examined from day 5 to 21 for the presence and number of colonies of M. canis and other fungi. Some samples were inoculated twice (initially negative or with a low number of M.canis). A total of 112 cultures were performed (14 duplicates) from 44 cats. On day 21, infection was detected in 23 cats (54.7%): 20 (87%) with the carpet method and 21 (91%) with the toothbrush method. None of the replicated cultures allowed the detection of new cases but three were subsequently negative. In eight cases, only one to six colonies of M. canis were obtained. Both methods used are easy to perform on cats and have a similar sensitivity of approximately 90%. The carpet method is, however, much less expensive, easier to prepare, mail, store and inoculate. The lack of growth in some duplicate cultures (initial development of one or two colonies) may explain the limits of diagnosis of infection and justify the need for multiple inoculations of agar with the toothbrush method. Funding: Self‐funded.     

P‐84 Experimental study of orange phototoxicity in sheep

We have evaluated the possible phototoxicity of an orange‐based diet on sheep in a controlled environment. The phototoxic effect of psoralens, potent phototoxic furocoumarins, contained in oranges could be manifested either as a perioral contact phototoxicity or as a postingestion phototoxic effect. This research has especial relevance in the region of Valencia, Spain, where sheep are occasionally fed large quantities of these agricultural by‐products and where sunlight is constant year‐round. Ewes were randomly allocated to two groups, one to be fed a maintenance diet (n = 9), and the other to receive, after a brief adaptation period, solely oranges (n = 6). The ewes were placed in an external enclosure and fed this diet for 2 months. At approximately 3‐week intervals, the ewes were subjected to thorough clinical and dermatological examination. Skin biopsies were obtained on two different occasions. All procedures were carried out under the guidelines of the local ethics committee. The sheep on the orange diet showed weight loss and a debilitated condition. However, during the study, no clinical or pathological signs of oral or systemic photodermatitis were observed. Funding: Self‐funded.     

P‐53 Histopathologic evaluation of feline plasmacytic pododermatitis

The purpose of this study was to evaluate the histopathologic changes seen in feline plasmacytic pododermatitis in an attempt to correlate clinical response with any specific histopathologic feature, and to evaluate these specimens for possible infectious organisms. Fourteen skin biopsies from cats with plasmacytic pododermatitis and a clinical follow‐up of 12–36 months were included in the study. Sections were stained with H&E as well as with a polyclonal anti‐Mycobacterium bovis [Bacille Calmette–Guerin (BCG)] antibody cross‐reactive to a broad spectrum of fungi and bacteria. Sections stained with the anti‐BCG antibody were graded as positive or negative. Inflammatory cell types and density, overall pattern, and the presence or involvement of adnexal structures were assessed in sections stained with H&E. All sections were negative for organisms within the actual footpad tissue with the anti‐BCG antibody stains. Two samples revealed a few foci of cocci on the outer surface of the ulcers. Funding: Self‐funded.     

P‐81 A retrospective study of equine sarcoidosis

The purpose of this retrospective study was to evaluate six cases of equine sarcoidosis for initial presenting symptoms, response to therapy and actual outcome. Dermatologists and dermatopathologists from Europe, the United States, Australia and Canada were contacted to obtain these six cases, as this is a rare disease. Signalment, clinical signs, histological findings, clinical management and outcome were determined via a questionnaire and compared to former reports. There was no age or breed predilection, and four of six horses were geldings. Age of onset ranged from 3 months to 17 years. Onset of the disease was insidious or rapid. Interestingly, in five of six cases, scaling began on the trunk (girth and shoulder). Scaling, crusting and alopecia were seen in all six horses. In one horse, clinical signs of systemic disease were reported and included intermittent fever, prescapular lymphadenopathy, depression, poor body condition and nasal discharge. Treatment included phenylbutazone, deworming agents, antibiotics, short‐term low‐dose corticosteroids, and 1–1.5 mg/kg of prednisolone. One horse showed a partial response to trimethoprim and sulfonamide, and five of six went into clinical remission with corticosteroid treatment. Five of six horses were still alive 1 year after diagnosis; one horse was diagnosed <12 months ago. Two horses are in complete remission 4 and 8 years after diagnosis. In both horses, clinical signs recurred after cessation of therapy and went into remission again with reintroduction of treatment. Both of these horses have been in remission for several years without therapy. Funding: Self‐funded.     

P‐30 Use of fipronil for treatment of Lynxacarus radovskyi in outdoor cats in Rio de Janeiro (Brazil)

The aim of this study was to report 20 cases of Lynxacarus radovskyi infestationin 20 cats. Lynxacarus radovskyi was diagnosed by physical examination and microscopic examination of plucked hair where countless adult mites and immature stages were identified. Microscopic examination was repeated every 7 days. The animals were observed daily for the first 7 days, and again on day 15 and day 30 for mites, pruritus and clinical signs. Clinical signs included salt‐and‐pepper appearance to a dull and opaque hair coat, alopecia of the dorsal and lateral areas of the hind limbs, and evidence of self‐mutilation. One case had papules and crusts of the hind limbs. The pruritus was mild in animals with low infestation, but very intense in those with a heavy infestation. Most mites occurred in the lateral area of the hind limbs and sacral area. Twenty of 100 animals had confirmed L. radovskyi infestation. Therefore, we suggest that the transmission occurs through fomites. Treatment consisted of 0.5 mL application of Fipronil^® (Frontline TopSpot) per cat, with resolution in 100% of cases by day 15. Funding: Merial.     

P‐5 Importance of psychogenic factors in canine recurrent pyoderma

Recurrent pyoderma is a relapsing bacterial infection of the skin. Evaluation of the primary predisposing factors is essential, but they are not always easy to determine. We reported that psychogenic factors should be considered as one cause of canine dermatoses featuring pruritic behavior such as grooming and scratching, and predicted that it could be added as a cause of recurrent pyoderma. The purpose of this study was to evaluate the roles of psychogenic factors in canine recurrent pyoderma. This study examined 21 dogs with recurrent pyoderma, which showed relapsing but antibiotic‐responsive skin lesions. Predisposing factors, especially allergy, infection, endocrine disorders, congenital factors and improper treatments, were carefully ruled out with standard diagnostic procedures. Diagnosis of psychogenic factors was based on fulfillment of the following features: (1) distinctive area of broken hairs or asymmetric erythema, (2) incidental pruritic behavior related to emotionally unstable situation or physiological intervention, (3) existence of environmental antecedent triggers or concurrent psychiatric symptoms, and (4) requirement for psychogenic treatment, consisting of behavior modification and psychopharmacological therapy in some. The incidence of psychogenic factors and the efficacy of the treatment in recurrent pyoderma were evaluated. In these 21 dogs, 10 cases (47.6%) were compatible with the presence of psychogenic factors, and seven cases (33.3%) were improved with behavioral treatment. Psychogenic factors should be considered in the aetiology of so‐called idiopathic canine recurrent pyoderma. Further investigation is needed to understand the relationship between skin barrier dysfunction and psychogenic factors. Funding: Self‐funded.     

P‐65 Canine cutaneous histiocytoma: morphology and morphometry

Canine cutaneous histiocytoma is a common tumor of young dogs. Nodules are single or multiple, alopecic and well demarcated. We studied 15 young dogs with cutaneous histiocytoma. Cutaneous nodules were cytologically and histologically investigated using routine techniques. The subject for morphometry was the nuclear area of histiocytes. The figures were statistically interpreted (Student's t‐test). Cytologically, histiocytes represented the largest population, being large‐sized cells. The nucleus:cytoplasm ratio was large with oval or bean‐shaped nuclei and a fine arrangement of chromatin. The cytoplasm was discrete and basophilic, or abundant and foamy. Five regressive stages were histologically described. Stage 1 was represented by dermal and hypodermal histiocyte proliferation, covered by an intact, uninfiltrated and atrophic epidermis. Epidermal ulcers and necrotizing foci with neutrophilic, lymphocytic and plasma cell infiltrations occurred in Stages 2, 3 and 4. Stage 5 looked like a chronic dermatitis. In Stage 1, the nuclear area was the smallest (4615 ± 62 pixels) with a small coefficient of variation (14.28%), proving a homogeneous population. Stage 2 histiocytes had a larger and more heterogeneous nuclear area (6116 ± 130 pixels) with a 21.12% coefficient of variation. In Stage 3, the average nuclear area (6431 ± 115 pixels) was larger than that for Stage 2 and had a 19.18% coefficient of variation. There were no significant differences between the nuclear areas of histiocytes from Stages 2 and 3; however, significant differences occurred between Stages 1 and 2, and between Stages 1 and 3. Funding: Self‐funded.     

Chiari‐like malformation in two cats

Two male, neutered, domestic, shorthaired cats were evaluated for progressive paresis and ataxia. Neurological examinations suggested a spinal cord lesion in each case. Complete blood examination and cerebrospinal fluid analysis were unremarkable in both cats. MRI revealed malformation of the occipital bone with herniation of the cerebellar vermis through the foramen magnum but without syringomyelia. Chiari‐like malformation was suspected in both patients. MRI repeated one year later in both cats because of progression of clinical signs yielded the same findings as the initial scans. Foramen magnum decompression in one cat was associated with resolution of clinical signs.     

Histoplasmosis infection in two cats from California

Systemic mycotic infections are typically localized to specific geographic regions of the country, because the organisms involved have certain environmental requirements for growth. Suspicion of infection relies on travel to or residence in recognized endemic regions. This report describes infection with histoplasmosis in two indoor cats from central California, an area not considered to be endemic for the disease. Systemic mycotic infections should be considered as differential diagnoses in any cat with compatible clinical signs, regardless of travel history or residence, especially if the cat is presented within a recognized endemic region.     

P‐77 Skin fungal flora in horses: is Malassezia an important component

The aim of this study was to evaluate the fungi present on the skin surface in healthy horses with a particular interest in Malassezia on predisposed skin areas. Twenty‐five mares were included, each sampled on nine skin areas including those most likely contaminated by Malassezia: nostrils, lips, ear pinnae, base of the mane, pasterns, pectoral areas, lateral thorax, udder and perianal areas. Two sterile carpets were applied to the skin, and then used for inoculation of agar (Sabouraud's plus cycloheximide and chloramphenicol), both with and without lipids for isolation of different species of Malassezia. This method is currently successful in isolating Malassezia in dogs. Cultures were incubated at 32°C, observed on day 5 for Malassezia, and then maintained at 27°C for complementary morphological identifications. From 223 cultures on standard medium, only seven remained sterile. The most common fungi were filamentous (number of positive samples): Scopulariopsis (156), Penicillium (79), Acremonium (67), Aspergillus (53), Paecilomyces spp. (38), and Stachybotrys (33). Interestingly, Microsporum gypseum was also isolated (14 samples from seven areas) from 10 horses. Yeast or yeast‐like fungi were Geotrichum (52), Trichosporon (21), and an additional 33 samples being positive for yeast other than Malassezia. Results from the other 223 cultures on lipid‐rich agar were similar. Most of the fungi were isolated from the nine areas selected, but Malassezia was never isolated from 446 cultures. Funding: Self‐funded.