Survey of dermatophytes on clinically normal cats in the southeast of England

To report the incidence of dermatophytes on the hair coat of asymptomatic cats in the southeast of England. Asymptomatic cats are often blamed for transmission of dermatophytes between animals and humans. This study may help to clarify whether cats are responsible for the increase in fungal infections among the human population.

A total of 169 clinically healthy cats without any dermatological signs were sampled using the Mackenzie brush technique and cultured for dermatophytes. Thirty cats were from a closed colony and 139 were feral or from domestic households in the southeast of England.

The incidence of Microsporum canis and Trichophyton mentagrophytes in household and feral cats was 2.16 per cent for each dermatophyte. This survey shows little difference in the isolation rates of M. canis between the southeast and southwest of England, which was reported on in 1994.

Given the low number of dermatophytes isolated, asymptomatic cats are unlikely to be responsible for the increasing incidence of human infection. Asymptomatic carriers with T. mentagrophytes in the hair coat have not been previously reported and may need to be considered when treating humans with trichophytosis.