Heartworm disease is a serious disease that results in severe lung disease, heart failure, other organ damage, and death in pets, mainly dogs, cats, and ferrets. A parasitic worm called, Dirofilaria immitis, causes this disease. These worms are spread through a mosquito bite. The dog is the definitive host, meaning that the worms mature into adults, mate, and produce offspring while living inside a dog. The mosquito is the intermediate host, meaning that the worms live inside a mosquito for a short transition period in order to become infective (able to cause heartworm disease). The worms are called “heartworms” because the adults live in the heart, lungs, and associated blood vessels of an infected animal.
Inside the host, the heartworm can grow into a parasite up to a foot in length. The parasite can cause injury to the lungs, arteries and the heart. Symptoms include:
• Difficulty breathing
• Exercise intolerance
These symptoms are also associated with other canine diseases so diagnosis can be difficult. Often, a blood test is required to confirm the diagnosis. Treatments are available but prevention and mosquito control are most important. In the United States, heartworm disease is most common along the Atlantic and Gulf coasts from the Gulf of Mexico to New Jersey and along the Mississippi River and its major tributaries, but it has been reported in dogs in all 50 states.
Your best weapon against heartworm is prevention. Heartworm treatment is difficult and expensive — and further complications to your dog’s health can occur. Medications used to prevent heartworm infections are called preventives. Preventives kill the heartworm larvae before they have a chance to grow and mature into adult heartworms. A number of heartworm preventives are available to pet owners today. Some heartworm preventives contain additional ingredients that will control other parasites, such as roundworms or hookworms. A monthly preventive should be given to all pets. Remember that mosquitoes can get indoors, so even though your pet may not go outside, he is still susceptible. Before administering heartworm medication, it’s important to have your dog tested by your veterinarian to make sure she is not already infected. Once your veterinarian has determined your dog is free of heartworm, you can start your dog on below listed medications, as prescribed by your veterinarian. If the test is positive, your veterinarian may discuss your treatment options.