Efficacy of Malarone(®) in dogs naturally infected with Babesia gibsoni

The efficacy of Malarone(®) alone and in combination with doxycycline (DOXY) against Babesia gibsoni infections was examined in 8 dogs. In all dogs except one treated with Malarone(®), parasitemia decreased, and anemia improved soon after initiation of treatment. However, 3 of 4 dogs treated with Malarone(®) relapsed, and relapse was inhibited in 2 of 4 dogs treated with Malarone(®) and DOXY. All relapsed dogs responded well to the second treatment, but 1 dog relapsed again and did not respond to the third treatment. Malarone(®) may be useful for acute stage of B. gibsoni infections, and at least second repeating treatment might be effective.