DOG HEARTWORM
(Dirofilaria immitis)
Canine heartworm disease is a clinical condition in
dogs
caused by a roundworm, Dirofilaria
immitis, which resides within the dog's heart and lungs. This disease, a serious and possibly
fatal veterinary problem, is
associated with dogs, coyotes and foxes. Canine heartworm is transmitted by the bite of an infected
Western Treehole Mosquito. The adult worm lives in the
right side of the heart and the adjacent large blood vessels and lungs, where it may attain
a length of 6 to 12 inches.
Many other mosquito species feed on dogs, but the Western Treehole
Mosquito is the most common carrier of heartworm. The outward symptoms of the disease are
not noticeable in most cases until reduced blood flow caused by adult worms damages the
heart, lungs, liver and kidneys. Advanced symptoms of heartworm may include: rapid tiring,
shortness of breath, chronic soft dry cough, listlessness and weight loss.
If you live in or travel to areas where treehole mosquitoes
occur, check with your veterinarian regarding treatment and prevention. Drugs are
available to prevent the disease, and it is curable if diagnosed in the early stages.
In California, the time of highest risk for dogs to
contract heartworm is through the spring and summer months; however, unseasonable rain may
extend this period.
DOG HEARTWORM LIFE CYCLE
1. A mosquito carrying heartworm bites a
dog. While the mosquito is feeding she deposits microfilariae 
(very small worms) into the dog's bloodstream.
2. As the microfilariae develop they migrate to the bloodstream, pulmonary arteries, and heart.
3. Mature females release microfilariae into the bloodstream where a female mosquito can pick them up when she feeds on the dog.
For more information on heartworm contact your local veterinarian
The information in this web page is also available in a brochure.
For More Information:
(530) 365-3768