Studies on Canine Dirofilariasis

摘要

The etiologic agent of canine heartworm is a nematode, Dirofilaria immitis. Once the infective larvae enter the normal definitive host, a dog, an intermediate growth phase ensues. Symptoms and signs of infection in the dog can vary according to worm load. Symptomatology normally includes a lack of endurance, anorexia and labored breathing. Specific signs may include a chronic cough, dry hair coat, loss of weight and hematuria. The research reported herein was in the nature of a survey. Specific factors and strain differences in mosquitoes which may influence the development of Dirofilaria immitis in Aedes triseriatus, were compared. The extent to whcih separate geographic strains of D. immitis may influence differences in the prevalence of canine dirofilariasis in regions with similar mosquito faunas had not been investigated previously. Therefore, the hypothesis that variation among divergent strains of D. immitis may influence the development of D. immitis in the mosquito was investigated. The responses of the arthropod host to such factors as age and colony inbreeding on the development of D. immitis were also examined.