A preliminary investigation of canine heartworm infection rates in Western North Carolina

Abstract

Dirofilaria immitis, more commonly known as canine heartworm, is a parasitic nematode that leads to heartworm disease in dogs. Adult heartworms occupy the heart and lungs of dogs and prevent these organs from functioning properly. Anecdotal evidence suggested that several counties in Western North Carolina showed a trend of heartworm incidence rates that were lower than the incidence rates of both North Carolina and the United States. This study looked to investigate this anecdotal trend using data from the Companion Animal Parasite Council. Public data confirm that both Madison and Buncombe County have lower rates of heartworm infection than North Carolina as a whole. In order to help explain this trend we conducted a pilot survey using Buncombe County as a model of mosquito species diversity in Western North Carolina. We trapped mosquitoes at three sites in Buncombe County from July 2020 to October 2020. Our mosquito diversity estimate was used to predict expected rates of heartworm prevalence and found a substantial difference between the actual and expected heartworm prevalence in Buncombe County. It is possible that factors other than mosquito diversity contribute to low heartworm prevalence in Buncombe County and in other counties in Western North Carolina.