Ensuring Health

Heartworms disease

Heartworms disease

Heartworms are dangerous internal parasites that live in the right ventricle and pulmonary artery to the heart. Adult worms can grow up to fourteen inches long, and a dog may have several hundred of them in his system. 

Heartworms is transmitted by the bite of a mosquito ( about sixty species are capable of carrying the disease). The cycle works something like this, when a mosquito feeds on an infected dog, it ingests blood which contains an immature form of heartworm called microfilariae. These incubate in the mosquito and, in as little as two weeks, become infective larvae. Then when the mosquito bites another dog, the infective larvae pass into the second dog. There, they migrate through its body tissues and enter the heart where they mature and begin to produce microfilariae, which enter the bloodstream. The complete cycle can take up to six months. 

Signs of heartworm disease include frequent coughing, listlessness, fatigue, lowered tolerance to exercise, laboured breathing, and faintness. Most symptoms, however, are usually not apparent until the disease has reached a serious stage. By this time the damage to the dog’s vital organs may be so severe that he cannot be saved. There fore, early diagnosis is important. 

To determine if your dog has heartworm, your vete4rinarian can examine a blood sample to see if any microfilariae are present. A dog occasionally may have adult heartworms but no microfilariae. In this case, X-ray and other tests necessary to confirm infection. If the dog has heartworm, the veterinarian may be able to treat him if the disease is detected early. 

Fifteen years ago, heartworm disease was prevalent mainly in the eastern and southern coastal areas of the United States, but now it is found throughout North America. No vaccine is available, but veterinarians have developed a method of prevention. It consists of giving small daily doses of diethyicarbamazine, either in liquid or pill form throughout the mosquito season. In areas of constant mosquito infestation, the daily medication must be given year-round. Dogs should be tested and show no signs of heartworm disease before the preventive program is started.