Epidemiology and clinico- therapeutic studies on dermatomycosis in dogs

Abstract

The present study was mainly focused on epidemiological, diagnostic and clinico-therapeutic aspects of dermatomycosis in dogs. A total of 94 animals showed positive results for the presence of arthrospores on direct microscopic examination, out of the total 11016 animals brought to University Veterinary Hospitals Kokkalai and Mannuthy from April 2003 to March 2004, were included in the infected group. No age, sex, breed predilection and seasonal variation for dermatophyte infection were observed. Clinical signs of the infected group are non-specific and quite variable, hence the diagnosis mainly relied on the examination of skin scrapings by direct microscopy and cultural method. Direct microscopic examination is considered to be an ideal method of diagnosis for detecting dermatophytes, since cultural method requires minimum of three weeks time and delays the treatment, even though, it is conclusive.

Isolates of Microsporum spp and Trichophyton spp were identified by cultural method using Sabouraud’s dextrose agar with chloramphenicol and cycloheximide supplement. Haematological abnormalities recorded were low haemoglobin content and leucopaenia and serum biochemistry revealed increased levels of total protein, albumin, globulin and A/G ratio in infected group compared to that of control group. No significant variations were observed on serum minerals such as copper, iron and zinc contents in infected group compared to control group. But mean values of copper and iron in infected and control groups were lower than the respective normal range in canine, where as zinc levels in both the groups were within the normal range. Three different therapeutic trials were conducted in three different experimental groups. Group 1 animals treated with ketoconazole at the dose rate of 5 mg per kg bodyweight daily orally for two weeks, showed a dramatic clinical response. Clinical examination of dogs at the end of treatment, revealed complete remission of lesions and signs of regrowth of hairs in almost all affected areas in all the animals. Terbinafine at the dose rate of 4 mg per kg body weight once daily orally given in-group 2 animals was proved to be very effective in treatment of dermatophyte infected dogs. Combination of intramuscular injection of “Biocan M” vaccine adsorbed with aluminium hydroxide and topical application of ketoconazole shampoo in-group 3 animals was not found to be effective. Hence the results of present study confirms the importance of the diagnosis of dermatophyte infections by direct microscopy, applicability of the cultural method of isolation of dermatophytes and proved the efficacy of ketoconazole and terbinafine as the good choice of drugs for the effective treatment of dermatomycosis.