Heartworm disease is a very serious and possibly fatal illness caused by parasitic worms that live in the arteries of the lungs and sometimes in the right side of the heart of dogs, cats and other mammalian species, including sea lions, foxes, wolves, ferrets, and (in very rare occasions) humans. Heartworms are classified as nematodes (roundworms) and are filarids, one of many species of roundworms. Dogs and cats of any age or breed can become infected with heartworm disease.
There have been cases of heartworm disease reported in all 50 states of the United States. Animals are infected with heartworm disease only by getting bitten by at least one mosquito that is infected. It takes roughly 7 months after the animal was bitten by the infected mosquito, before the heartworm larvae will mature into adult worms. Then the worms will lodge in the lungs, heart, and surrounding blood vessels and begin multiplying. Adult heartworms can reach up to 12 inches long, and can live for 5-7 years. An infected dog can have up to 250 worms in his system.
When an animal gets infected with heartworm disease, there are not any symptoms initially, but as more worms begin to crowd the lungs and heart of the animal, most infected animals will develop a cough. As time goes by and the illness progresses, the animal will not be able to exercise as much, and will become winded with any exercise. In severe heartworm cases, it is possible to hear abnormal lung sounds, some animals will begin passing out from lack of blood flow to the brain, and many animals will retain fluid. Most animal will die if the heartworms are left untreated.
If your dog has heartworm disease, there is an effective treatment, although it is quite expensive. An injectable arsenic-based drug, called Immiticide can be administered in two to three separate injections that will kill the adult heartworms in the blood vessels of the heart. It is extremely important to keep you dog quiet both during and following the the Immiticide injections, because as the worms die, they break into pieces, which can cause a blockage of the pulmonary vessels leading to death. Most dogs that die following heartworm therapy die because they were exercising, not because of the actual drug therapy.
The safest way to treat a dog that is infected with heartworm disease requires an extensive pre-treatment evaluation, including blood tests, X-rays, and additional tests to determine the severity of the disease. With all of the prep work, treatment for heartworm disease can run as high as $1,000. Just the injections of Immiticide can be administered for around $300, or so.
For dogs, in particular, prevention is the best option when it comes to heartworm disease. There are monthly pills, a six-month injectable product, and monthly topical products that are applied to the dog’s coat and skin. The average annual cost for heartworm prevention is between $35 and $100. This number is obviously considerably smaller than treatment once the dog is infected. Preventative medicine will not provide much help for a dog that is already infected, as the preventative medicine will only kill the heartworm larvae, not the adult worms. If someone cannot afford Immiticide treatment for their dog, using the monthly preventative medicine will limit the number of full grown worms in the infected dog’s system, but will not eliminate the adult worms. The dog really needs to have the full arsenic-based medication if he is going to fully recover. Once the dog recovers, he will need to be put back on the monthly preventative therapy, or he could become infected again.
