Animals can get heartworm disease if bitten by an infected mosquito, there is no other way to get heartworms. They spend their adult life in the right side of the heart and the large blood vessels connecting the heart to the lungs. Heartworms are found in dogs, cats, ferrets and also live in other mammal species.
Dogs: In dogs an adult heartworm can obstruct the various blood vessels leading from the heart to the lungs. It takes about 7 months, once a dog is bitten by an infected mosquito, for the larvae to mature into adult heartworms. They cause lasting damage to the heart, lungs, arteries and can damage other organs in the body.
Cats: Heartworm disease in cats can be very different from heartworm disease in dogs. Cats are an atypical host for heartworms, and most worms do not survive to the adult stage. Even immature worms cause real damage in the form of a condition known as heartworm associated respiratory disease. The heartworm medication used to treat dogs cannot be used on cats, so prevention is the only means to protect cats from the affects of the disease.
What are signs of a heartworm infection and how is it diagnosed?
Most animals with heartworm infections DO NOT show any signs of the disease. Some pets may show decreased appetite, loss of weight and fatigue. Often, the first sign of the disease is a cough. Animals with severe heartworm disease will show lack of endurance during exercise. Some will accumulate fluid in their abdomen which gives them a swollen belly. In rare situations, the animals may die of sudden heart failure.
Dogs with a large number of heartworms can develop a sudden blockage of blood flow within the heart leading to a life-threatening form of cardiovascular collapse.
Blood testing is preformed to identify the heartworm parasite. Because blood tests are not always accurate, results must be interpreted in relation to the animals history and symptoms. X-rays and ultrasounds are usually preformed to look for typical changes in the heart and lungs and determine the severity of the infection. Additional findings can help support the diagnosis.
What is a good heartworm prevention program?
The best program for prevention of heartworm infection includes using preventives, preforming routine heartworm testing, and reducing exposure to mosquitoes.
Medications used to prevent heartworm infections are called preventatives. The first thing to remember is that preventatives are NOT used to kill the adult worm. Special drugs must be used to kill adult heartworms. Some preventatives can cause severe problems if given to animals with adult heartworms. Follow the recommendations of your veterinarian in regard to testing prior to giving the preventative.
Daily preventatives are available with a prescription through compounding pharmacies. Two major disadvantages are that it can produce severe reactions if given to an animal with a heartworm infection, and that even missing two or three days of administration could result in a lapse of protection.
My animal has heartworms, whats the treatment?
The safest way to treat heartworms includes an extensive pre-treatment workup, including X-rays, blood work, and all the tests needed to establish how serious the infection is. The drug used to treat hearworms is then given by injection. The injection will kill adult heartworms in the blood vessels of the heart. It is extremely important to not let your dog exercise after being treated for heartworm disease. When the worms begin to die, they break up into pieces, which can cause blockage of the pulmonary vessels and cause death. Studies show that most dogs that die after heartworm treatment do so because the owners let them exercise, this is why animals must keep quite for several months afterwards.
Remember, if you leave a heartworm untreated there is a good chance your animal will die from the disease!