Dog Heartworm

Appearance

There are four genera of mosquitoes that transmit dirofilariasis, Aedes, Culex, Anopheles, and Mansonia. The definitive host is the dog, but it can also infect cats, wolves, coyotes, jackals, foxes, ferrets, bears, seals, sea lions and, under rare circumstances, humans.

Distribution

Although at one time confined to the southern United States, heartworm has now spread to nearly all locations where its mosquito vector is found. In the southeast region of the United States, veterinary clinics saw an average of more than 100 cases of heartworm each in 2016. Transmission of the parasite occurs in all of the United States , and the warmer regions of Canada. The highest infection rates are found within 150 miles of the coast from Texas to New Jersey, and along the Mississippi River and its major tributaries. It has also been found in South America, southern Europe,
Southeast Asia, the Middle East, Australia, Korea, and Japan.

Behavior

''Dirofilaria immitis'' is commonly called "heartworm". Adult heartworms often reside in the pulmonary arterial system as well as the heart, and a major health effect in the infected animal host is a manifestation of damage to its lung vessels and tissues. In cases involving advanced worm infestation, adult heartworms may migrate to the right heart and the pulmonary artery. Heartworm infection may result in serious complications for the infected host if left untreated, eventually leading to death, most often as a result of secondary congestive heart failure.