• Nine species have been identified in dogs, but Babesia gibsoni and Babesia canis are currently the most common in the United States.
• Babesia gibsoni and B. canis can both be transmitted through ticks and, rarely, blood transfusions; however, B. gibsoni can also be transmitted dog-to-dog via bites.
• Babesia gibsoni is prevalent in pit bull populations, whereas B. canis is commonly identified in greyhounds.
• Piroplasms of Babesia species can be found within erythrocytes.
• Because of the increased weight of parasitized erythrocytes, they are often pushed to the feathered edge of the smear.
• Babesia gibsoni inclusions appear as small, pleomorphic ring-shaped organisms (Figure 3).
• Babesia canis inclusions are much larger than those of B. gibsoni. They are teardrop-shaped and often found in pairs (Figures 4A & 4B).
3. Babesia gibsoni on a blood smear. It can look similar to Cytauxzoon species (Figures 5A-5C), but B. gibsoni is exclusively seen in dogs, whereas Cytauxzoon species is exclusively seen in cats (Wright’s stain; 50x).
4A & 4B. Babesia canis on a blood smear. It is common to find multiple piroplasms within one red blood cell (Wright’s stain; 100x).
Clinical and laboratory signs
• Moderate to severe hemolytic anemia
• Cyclic fever
• Hyperglobulinemia (seen as an elevated total protein concentration on a refractometer)
• Therapy is aimed at treating specific Babesia species, so correct identification is imperative.
• Babesia gibsoni infection is treated with atovaquone (13.5 mg/kg orally three times a day) given with a fatty meal, plus azithromycin (10
mg/kg orally once a day) for 10 days.
• Babesia canis infection is treated with imidocarb (6.6 mg/kg given subcutaneously or intramuscularly, repeated in two weeks). Premedicating
with glycopyrrolate is suggested.
• Do not give prednisone until treatment of the parasitic infection is concluded.