Protozoal and Protozoa-Like Infections

This chapter focuses on important protozoal diseases in dogs and cats with emphasis on etiology, pathophysiology, clinical manifestations, diagnosis, treatment, and prevention. It discusses several infections such as toxoplasmosis, neosporosis, American trypanosomiasis, African trypanosomiasis, leishmaniosis, hepatozoonosis, feline cytauxzoonosis, babesiosis, and giardiasis. Exposure to Toxoplasma gondii in cat populations is widespread and positive serology may be detected in up to 74% of cats in domestic feline populations worldwide. Dogs have also been reported to have high exposure to T. gondii with seroprevalence rates ranging from 30% to 64% in different countries and populations. Clindamycin is the current treatment of choice in dogs and cats with clinical toxoplasmosis. The clinical manifestations of canine neosporosis are due to inflammation and necrosis caused by cellular destruction induced by tachyzoites. While Trypanosoma brucei and T. conglonese cause African trypanosomiasis, T. cruzi causes American trypanosomiasis.