Heartworm

The title of this illness, unfortunately, does in fact describe a parasitic worm that lives in the heart and arteries of infected animals. Heartworm is an illness transmitted from one animal to another by mosquitoes. Screening for heartworm should be done on an annual basis through blood testing.

Quite disturbingly these parasites travel through the bloodstream, damaging arteries and organs, and typically spreading after six months all the way to the heart and lungs. Symptoms can be weight loss, fatigue, laboured breathing, coughing, vomiting, or no symptoms at all. However, this condition, thankfully, is easily preventable with inexpensive medication, but if left untreated can be fatal.

Heartworm disease, or dirofilariasis, is a serious and potentially fatal disease. It is caused by a blood-borne parasite known as Dirofilaria immitis.

Adult heartworms are found in the heart, pulmonary artery, and adjacent large blood vessels of infected dogs. Rarely, worms may be found in other parts of the circulatory system. Female adult heartworms are 6 - 14 long (15 - 36 cm) and 1/8 wide (3 mm). Males are about half the size of females. One dog may have as many as 300 worms present when diagnosed.

Adult heartworms may live up to five years. During this time, females produce millions of offspring called microfilaria. These microfilariae live mainly in the small vessels of the bloodstream.