A Case of a 5-Week-Old Puppy with Babesiosis Treated with Atovaquone-Proguanil Hydrochloride

Abstract

A 5-week-old beagle puppy was presented to Kagoshima University Veterinary Teaching Hospital with anemia, thrombocytopenia, and splenomegaly. We elected to treat the puppy with atovaquone-proguanil hydrochloride based on a positive result for Babesia gibsoni (B. gibsoni ) in PCR testing. After receiving 20 mg/kg BID atovaquone for 10 days, the anemia was ameliorated and the puppy experienced no adverse reactions. This case involved a breed of hound, the puppy's dam had not completed her tick prevention treatment, and another dog cohabitant with the dam had also developed babesiosis. Accordingly, vertical transmission was suspected as the route of infection, even though B. gibsoni was undetectable in the dam (a probable false-negative result in PCR testing). Here, we present the first report on atovaquone treatment for a puppy with acute B. gibsoni infection in Japan.