Both Babesia canis canis and Babesia canis vogeli are present in Italian dogs with clinical signs compatible with tick-borne diseases. The clinicopathological patterns of these two species show differences, though.

A team at the Universities of Montpellier I and II led by Dr. Laia Solano-Gallego used PCR-restriction fragment length polymorphism (RFLP) to determine the presence of Babesia spp. in blood samples from Italian dogs. Writing in Veterinary parasitology, they furthermore describe the clinicopathological findings of dogs with Babesia infection.

Most cases of canine babesiosis were evaluated by means of clinical history, physical examination, hematological, biochemical, serum electrophoresis, urinalysis and hemostatic tests, the researchers report.

Analysis of data revealed that 45 out of 164 canine blood samples studied were positive to Babesia PCR-RFLP. Babesia canis canis was found in 34 blood samples and Babesia canis vogeli in 11 samples. “The majority of Babesia canis canis infections were detected in Northern Italy. Babesia canis vogeli cases were detected mainly in Central and Southern Italy,” Solano-Gallego’s team reports.

In addition, the researchers selected three positive samples to Babesia canis canis and four positive samples to Babesia canis vogeli for sequencing of a fragment of the 18S rRNA gene for further molecular characterization.

Sequencing showed that the sequence obtained from all seven dogs was 99% homologous to sequences from Babesia canis canis and 100% to sequences from Babesia canis vogeli. Interviewing the dog’s owners yielded the information that 62 percent of dogs infected with Babesia canis canis had recently travelled on a hunting trip to East European countries.

As main acute clinical signs the team reports dehydration, apathy, anorexia and fever. Furthermore, the majority of dogs infected with Babesia canis canis presented at initial clinical examination mild to severe thrombocytopenia, hyperfibrinogenemia, mild to moderate normocytic-normochromic non-regenerative anemia, hemolysis and neutropenia, they add. The urinalysis showed hemoglobinuria in 13 of the 19 dogs suggesting intravascular hemolysis.

Further analysis demonstrated that dogs with Babesia canis canis infection had high levels of C-reactive protein and that hypoalbuminemia was present in 17 of 26 dogs. The 11 cases of Babesia canis vogeli infection did not present a homogenous clinicopathological pattern.

“Babesia canis vogeli infections were observed in young dogs causing hemolytic anemia and in adult/old does that frequently presented predisposing factors such as splenectomy or immunocompromised conditions”, the investigators note and conclude that  “this study demonstrates the presence of Babesia canis canis and Babesia canis vogeli in Italian sick dogs and differences in clinicopathological pattern in these two species of Babesia canis.”

References

• Veterinary Parasitology, Volume 157, Issues 3-4, 7 November 2008, Pages 211-221