Heartworm Disease in Dogs
What causes heartworm disease in dogs?
Heartworm disease in dogs is a serious and potentially fatal condition. Heartworm is transmitted through the bite of an infected mosquito. An infected dog has parasitic worms (heartworms) living in the major blood vessels of the lungs and heart.
Adult heartworms can live up to five years. During this time, the female produces millions of offspring called microfilaria. These microfilaria live mainly in the small vessels of a dog’s bloodstream. The female worm is 6-14 inches long and 1/8 inch wide. The male is about half the size of the female. One dog may have as many as 300 worms present when diagnosed.
What is the life cycle of the heartworm?
The life cycle begins when a female mosquito bites an infected dog and ingests the microfilariae during a blood meal. The microfilariae develop further for 10-30 days in the mosquito’s gut and then enter its mouth parts. At this stage, they are infective larvae and can complete their maturation after they enter the dog’s body, following the mosquito bite. The larvae migrate into the bloodstream and move to the heart and adjacent blood vessels, maturing to adults, mating and reproducing microfilariae within 6-7 months.
What do heartworms do to the dog?
Adult heartworms cause disease by clogging the heart and major blood vessels leading from the heart. They also interfere with the valve action in the heart. By clogging the main blood vessel, the blood supply to other organs of the body is reduced, particularly blood flow to the lungs, liver and kidneys, causing these organs to malfunction.
The most obvious clinical signs of heartworm disease are a soft, dry cough, shortness of breath, weakness, nervousness, listlessness, loss of stamina, and weight loss.
How do you monitor for heartworm?
At Gruda Veterinary Hospital, we recommend testing for heartworm one a year. If a dog is on prevention all year, we still recommend a heartworm test as a safety net.
How do I prevent my dog from getting heartworm?
We recommend using one of the safe and affordable heartworm preventatives available today:
- Proheart 6 (an injection given once every 6 months)