Persistent cryptosporidiosis and lymphocytic duodenitis were documente
d in an 18-month old Domestic Shorthair cat. Systemic immunosuppressio
n or other concurrent diseases were not documented, Clinical signs of
disease, Cryptosporidium parvum oocyst shedding, and lymphocytic duode
nitis resolved following the administration of clindamycin hydrochlori
de and tylosin.