Clinicopathological changes and effect of imidocarb therapy in dogs experimentally infected with Babesia canis

Abstract

In this study one spleen-intact dog (A) and two splenectomised dogs (BSE, CSE) were infected with Babesia canis. All animals developed an acute disease characterised by fever, haemoglobinuria and anaemia, the latter being more severe in the splenectomised dogs. Fever and parasitised red blood cells were detected for three days after imidocarb treatment in the splenectomised animals. Haematological abnormalities included regenerative anaemia, thrombocytopenia and leukopenia (due to neutropenia and lymphopenia) in the acute phase, soon followed by leukocytosis, neutrophilia and left shift a few days later. Acute hepatopathy was detected in all dogs with elevated ALT activity, which was more seriously altered in the splenectomised dogs. Diffuse changes in liver structure and hepatomegaly were seen by ultrasonography. Liver biopsy and histology revealed acute, non-purulent hepatitis in the splenectomised dogs. Both splenectomised dogs were successfully cured after collection of 400 ml highly parasitised blood, proving that large-amount antigen production is possible with rescuing the experimental animals. Whole blood transfusion, imidocarb and supportive care with infusions, antipyretics, glucocorticoids and diuretics were applied. The spleen-intact dog clinically recovered after receiving supportive treatment, with no imidocarb therapy. Microbial infections developed in both splenectomised animals (BSE: haemobartonellosis, CSE: osteomyelitis caused by Escherichia coli), probably as a consequence of immunosuppression after splenectomy and glucocorticoid therapy.