Eight young cats, aged between 2 and 3 months were experimentally infected with Microsporum canis by applying a suspension of aleurioconidia, for two consecutive days on gently irritated and clipped areas of skin. In for cats the infection region was represented by the thoraco-abdominal region, while in the other for cats by the head (frontal region). Cutaneous lesions were followed for 16 weeks. For the evaluation of lesion severity, we followed a mark-based system in order to determine a lesional score.
The technique and inoculation area used, successfully induced the infection with Microsporum canis in all cats. The duration of clinical evolution was about 90 days. In one cat infected on the thorax, clinical healing occurred in 38 days while in two cats infected on the head, healing occurred in 102 and 118 days, respectively. On the basis of the lesional score we have established that clinical evolution was stadial with differences regarding the duration of each phase and the severity of lesions. Thus, incubation period was 1-2 weeks in both regions; progression period was 2 weeks on the thorax and 4 weeks on the head; stagnation period was 7 weeks on the thorax and 4 weeks on the head and regression lasted for 3-5 weeks in both infected regions. The severity of the lesions (expressed as marks) on the head was higher than on the thorax. The lesional structure was also different on the two areas. On the thorax erythema and scaling were most frequent, while on the head crusts and lichenification. Satellite lesions appeared in all cats infected on the head and in only one cat infected on the thorax.
As far as we know, this is the first experimental model for the Microsporum canis infection in cats using the head as infection area.