Effects of imidocarb dipropionate in cats with chronic haemobartonellosis

The objective of this study was to evaluate the safety and efficacy of imidocarb dipropionate administered to cats for clearing chronic Haemobartonella felis infections. Imidocarb dipropionate was administered twice at 5.0 mg/kg by intramuscular injection 14 days apart to eight cats with chronic, subclinical haemobartonellosis. Clinical signs and laboratory parameters were monitored throughout the study. Polymerase chain reaction (PCR) for the detection of Mycoplasma haemofelis (large form of H. felis) and Mycoplasma haemominutum (small form of H. felis) was performed to assess for parasitologic cure. Four of the eight cats treated with imidocarb dipropionate became transiently PCR-negative after treatment; untreated control cats (n = 2) were persistently PCR-positive. Two persistently PCR-negative cats were given one dose of methylprednisolone acetate; one was PCR-positive 10 days later. There was no evidence of significant toxicity associated with this imidocarb treatment protocol.