Random subjects of the canine population brought to the veterinary clinics on Gran
Canaria Island for routine health care examinations or procedures were included in the
survey. All dogs were 6 months old or older, and many breeds were represented. None
of the dogs in the study received heartworm chemoprophylaxis or chemotherapy. The
dogs were randomly selected by the veterinarians, and the samples were obtained by
cephalic venipuncture and kept refrigerated until assayed in our laboratory. A record
form was completed for each dog, giving pertinent identification, history and demographic
data. Blood was remitted to our laboratory where a haemagglutination test
Vetred Dirofilariaw, Rhoˆne Me´rieux. was used for serologic detection of D. immitis
antigens.