Facial alopecia, scaling and erosions in a Jack Russell terrier Author: Ross BondEditor: David Lloyd © European Society of Veterinary Dermatology

History | Signs | Differentials | Tests | Therapy | Notes Click to reveal the text on this screen Click the forward arrow to jump to the next screen History - 1 History 10 year-old entire male Jack Russell terrier Good general health Progressive facial skin disease of 4 months duration No response to ampicillin and prednisolone

History | Signs | Differentials | Tests | Therapy | Notes History - 2 History Dog lives in rural environment Lesion began as focal area of erythema and scaling caudal to nasal planum Progressed caudally over face despite therapy

History | Signs | Differentials | Tests | Therapy | Notes Clinical signs - 1 Signs Severe skin disease; lesion well-demarcated Smooth-silvery skin at healing areas rostrally Alopecia, scaling, erosions Nasal planum unaffected

History | Signs | Differentials | Tests | Therapy | Notes How would you approach this case? Signs What are the next steps you would take? Make a list of your principle differential diagnoses List any samples you would collect List any tests you would perform to assist in making a definitive diagnosis

History | Signs | Differentials | Tests | Therapy | Notes Tests - 1 Differentials Principle differential diagnoses Dermatophytosis Demodecosis Deep pyoderma Pemphigus foliaceus

History | Signs | Differentials | Tests | Therapy | Notes Tests - 2 Tests Diagnostic tests Skin scrapings Woods light examination Fungal and bacterial cultures (Skin biopsy)

History | Signs | Differentials | Tests | Therapy | Notes Results - 1 Tests No evidence of parasites & fungal elements on microscopy No fluorescence on Woods light examination Fungal growth evident on mycobiotic agar within 7 days of incubation

History | Signs | Differentials | Tests | Therapy | Notes Results - 2 Tests White colonies with granular texture Dark tan / brown reverse pigment On microscopy, numerous microconidia and thin-walled cigar-shaped macroconidia Trichophyton mentagrophytes (granular form) Fungal culture: Sabourauds dextrose agar, 5 days

History | Signs | Differentials | Tests | Therapy | Notes What is your diagnosis? Tests Do the investigations permit a definitive diagnosis? Are there any additional investigations which you think may need to be done?

History | Signs | Differentials | Tests | Therapy | Notes Diagnosis Tests Dermatophytosis caused by T. mentagrophytes Historical and clinical features strongly suggestive, supported by culture results Skin biopsies confirmed hair shaft and follicle invasion by fungal elements

History | Signs | Differentials | Tests | Therapy | Notes How would you deal with this case? What is your prognosis? How will you advise the owner? What treatment would you consider? Tests

History | Signs | Differentials | Tests | Therapy | Notes Prognosis Tests Prognosis is good However, lengthy antifungal therapy is often needed with Trichophyton infections in dogs

History | Signs | Differentials | Tests | Therapy | Notes Therapy Griseofulvin orally at 50 mg/kg (divided twice daily) Enilconazole (Imaverol) emulsion applied every 4th day Good clinical response after 8 weeks of therapy, but repeat cultures still positive Cultures negative and complete clinical response after 12 weeks of treatment, which was withdrawn at this time No relapse over a 6 month follow-up period

History | Signs | Differentials | Tests | Therapy | Notes Comment -1 Notes Owners lesions were present in this case, illustrating the zoonotic potential of canine dermatophytosis Jack Russell terriers are predisposed to sylvatic dermatophytosis in the U.K. The peripherally expanding, well-demarcated lesions on the face were suggestive of dermatophytosis

History | Signs | Differentials | Tests | Therapy | Notes Comment -2 Notes Lesions of dermatophytosis vary in appearance and severity Severely inflamed Trichophyton lesions on the face are misdiagnosed as pemphigus foliaceus Absence of focal crusted lesions (footprints of vesicopustules) and nasal planum involvement made PF much less likely in this case

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