Incidence of Canine Babesia gibsoni Infection and Subclinical Infection among Tosa dogs in Aomori Prefecture, Japan

Abstract

ABSTRACT. To identify the incidence of Babesia gibsoni (B. gibsoni) in Aomori Prefecture, northeastern Japan, dogs with acute B. gibsoni infection were investigated at the Animal Teaching Hospital, Kitasato University, between April 2002 and March 2003. Eighteen dogs with acute B. gibsoni infection were recognized; they were all male dogs of the fighting dog breed Tosa. Their platelet counts were below normal and their packed cell volumes (PCVs) were at various levels. We collected blood samples from 141 Tosa dogs from Aomori Prefecture and used polymerase chain reaction assay to investigate the incidence of subclinical B. gibsoni infection. We also looked into the serological abnormalities associated with thrombocytopenia or anemia in subclinical infection. Forty-one of 87 dogs (47.1%) with histories of dog fighting, and one dog of 54 without a history of dog fighting were positive for B. gibsoni; that is, 42 of 141 dogs (29.8%) showed a positive result. The mean platelet counts of dogs with subclinical infection were significantly lower and levels of anti-platelet IgG were significantly higher than levels for dogs without infection. Anti-erythrocyte membrane IgG levels were significantly higher in dogs with subclinical infections, although mean PCVs were not significantly different. Tosa dogs from Aomori Prefecture, Japan, were highly infected with B. gibsoni subclinically and this pathogen might be successfully transmitted during dog fighting. Dogs with subclinical infections were at risk of chronic thrombocytopenia, which may be due to autoimmune mechanisms. KEY WORDS: anti-erythrocyte membrane IgG, anti-platelet IgG, Babesia gibsoni, Tosa dog.

Epidemiological Survey of Babesia gibsoni Infection in Dogs in Eastern Japan

“…However, Haemaphysalis longicornis, a predominant tick species in dogs, is known to transmit B. gibsoni [11]. It is widely distributed throughout Japan, including eastern Japan, the area of this study [17]. Thus, it is also possible that B. gibsoni is transmitted through blood from infected dogs to ticks and may be established among ticks in the eastern part of Japan.…”

“…In Japan, it is distributed mainly in the western part [3,4,7,8] and only a few epidemiological and clinical studies have been reported on canine B. gibsoni infection in eastern Japan. All of the confirmed cases of B. gibsoni infection in the eastern part of Japan were found among Tosa dogs, a fighting breed raised only in Aomori Prefecture [3,10,17]. Transmission of B. gibsoni in this area was thought not to occur via ticks [3], although the vector tick species, Haemaphysalis longicornis, is distributed throughout Japan [19].…”

A Possible Treatment Strategy and Clinical Factors to Estimate the Treatment Response in Bebesia gibsoni Infection

“…B. gibsoni infected dogs are generally seen in the west of Japan and dogs affected by B. canis are mainly observed on Okinawa island. However, the incidence of canine babesiosis, especially B. gibsoni infection, has been recently reported to be increasing, and the areas affected are expanding towards the northeastern part of Japan [15,17,27]. Clinical symptoms of canine babesiosis include anorexia, depression and exercise intolerance as a result of hemolytic anemia.…”

Evaluation of doxycycline sensitivity in vitro against Babesia gibsoni by Real Time-PCR

“…B. gibsoni infected dogs either clinical patient or experimental are required for this method. Our laboratory established a continuous culture of B. gibsoni isolated from Tosa dogs (Matsuu et al, 2004a). There is no precise report emphasizing the efficacy of doxycycline sensitivity alone in vitro against B. gibsoni by RT-PCR.…”