Abstract
ABSTRACT A retrospective review of hematological reports of nine dogs detected with Hepatozoon canis infection by microscopic examination of blood smears in a laboratory in the municipality of Dourados, Mato Grosso do Sul, Brazil was conducted. This study aimed to evaluate the hematological profile of these infected dogs, in addition to the occurrence of coinfections with other agents that infect blood cells, since studies concerning canine hepatozoonosis in Brazil are scarce and there are some divergences regarding H. canis infection that still require a resolution. The nine cases of H. canis infection were identified among all dogs examined at the studied laboratory in 2009 and 2010, with an occurrence of 7/1,192 (0.59%; 95% CI 0.15 - 1.02%) positive dogs in the first year and 2/1,313 (0.15%; 95% CI 0.02 - 0.55%) cases in 2010. The analysis of the hematological reports showed an occurrence of coinfection between H. canis and other agents in two (2/9; 22.22%; 95% CI 2.81 - 60.00%) dogs, one with E. canis and another with Babesia spp. (1/9; 11.11%; 95% CI 0.28 - 48.24%). Only the blood test of one dog had no alterations, based on reference values. Anemia was the most frequent hematological alteration (6/9; 66.67%; 95% CI 29.93 - 92.51%). Although the occurrence of H. canis infection was low, significative hematological alterations were observed in most infected dogs. Coinfection with Babesia spp. and E. canis was detected in two dogs and the hematological alterations cannot be attributed exclusively to H. canis in these animals. Longitudinal studies would be of fundamental importance to determine the causality of these alterations. These results highlight the importance of differential diagnosis in dogs when there is clinical suspicion of infection by hemoparasites, since the hematological changes in dogs infected by H. canis are quite variable.
Highlights
Parasites detected in canine blood include protozoa of the genus Hepatozoon (Apicomplexa: Hepatozoidae), which contains hundreds of species, but two are infectious to dogs: H. canis and H. americanum
The nine cases of canine infection by H. canis were detected by direct observation in blood smears among 2,505 (9/2,505; 0.36%; 95% confidence intervals (95% CI) 0.12 – 0.59%) dogs examined from January 2009 to December 2010
In 2009, 7/1,192 (0.59%; 95% CI 0.15 - 1.02%; average = 0.58 cases/month) dogs were positive for H. canis, which represents 7.61% (7/92; 95% CI 2.19 - 13.03%) of dogs diagnosed in this year with infection by at least one of these three agents (Babesia spp., Ehrlichia canis and/or H. canis)
Summary
Parasites detected in canine blood include protozoa of the genus Hepatozoon (Apicomplexa: Hepatozoidae), which contains hundreds of species, but two are infectious to dogs: H. canis and H. americanum. The latter is responsible for canine hepatozoonosis in North America, with characteristics that differ from those that occur in the rest of the world (VincentJohnson et al, 1997; Baneth et al, 2000). Dogs become infected with H. canis by ingesting a tick vector containing the parasite in its body cavity. The infection by the protozoan occurs in regions where its main vector and definitive host is found (Vincent-Johnson et al, 1997), the tick species Rhipicephalus sanguineus, known as the brown dog tick (Nijhof et al, 2005). No single diagnostic method has been used as the sole means of confirming tick-borne diseases (Mylonakis et al, 2004) and it is common to perform blood test when there is suspicion of infection by hemoparasites in dogs, to check and to determine what kind of alterations were induced
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
