Canine heartworm disease: a review and pilot study

Canine heartworm disease is a mosquito vectored illness resulting from parasitization by the filariid worm Dirofilaria immitis. While presenting some danger to humans, the filariid has its greatest impact on the canine population. In recent years the disease has become established throughout much of the United States, perhaps as the result of diffusion from a suspected hearth in the southeastern coastal plain. While its distribution is known in general terms, much research remains to be done to assess the pattern of distribution as well as the impact of D. immitis on canine populations and their human owners for many locales. The present study provides a review of the literature on the parasite; on its distribution, particularly in the United States; and on the ecology of canine heartworm disease. A pilot study is presented which emphasizes the problems encountered in establishing a data base for observations on the disease at the local level.