Three hundred ninety five dogs from selected six municipalities were examined for canine dirofilariasis or canine heartworm disease using Modified Knott's test with the following objectives: (1) to determine the prevalence of canine dirofilariasis in selected municipalities of Nueva Vizcaya; and (2) to determine the influence of breed, age, sex, type of rearing, vaccination, deworming and treatment history on the prevalence of canine dirofilariasis.

There was no prevalence of canine dirofilariasis in the six municipalities of Nueva Vizcaya. One hundred percent of the 395 dogs tested were negative for Dirofilaria immitis microfilaria. The influence of breed, age, sex, type of rearing, vaccination, deworming and treatment history was not determined due to the negative prevalence of the disease.

A further study on other municipalities of Nueva Vizcaya is recommended, considering the areas with polluted waters like canal, where mosquito as an intermediate host of canine dirofilariasis thrived.

Thesis (Doctor of Veterinary Medicine)

Includes appendices and bibliographical references.