Among the options for treating ringworm in shelter cats, the drug itraconazole with concurrent twice-weekly lime-sulfur dips is most highly recommended in a protocol developed by Sandra Newbury, DVM and Karen A. Moriello, DVM, DACVD. In a recent study co-authored by Drs. Moriello and Newbury, the use of oral terbinafine was also identified as a well-tolerated, effective treatment.

Terbinafine needs to be given for a minimum of 21 days; cats treated for only 14 days initially improved but relapsed later. The study involved 85 shelter cats with naturally occurring M. canis dermatophytosis, and during the trial, the cats also received twice-weekly lyme-sulphur dips.

Moriello, K., Coyner, K., Trimmer, A., Newbury, S. and Kunder, D. (2013), Treatment of shelter cats with oral terbinafine and concurrent lime sulphur rinses. Veterinary Dermatology, 24: 618–e150. doi: 10.1111/vde.12069