Heartworm diseases in pets are caused by the parasitic worms of the same name. Scientifically, the worm is called as Dirofilaria immitis, which infects the heart and lungs, particularly, their blood vessels resulting in health issues as mild as cough to as severe as heath failure.
Adult heartworms resembles to cooked spaghetti. Males measure about 4 to 6 inches in length and females reach about 10 to 12 inches in length. The number of worms living inside an infected dog is called the worm burden. The average worm burden in dogs is 15 worms, but that number can range from 1 to 250 worms. The average lifespan of an adult heartworm is 5-7 years.
Mosquitoes work as the vector of the heartworm’s larvae or offspring known as microfilariae. They spread the heartworm diseases in dogs, cats and ferrets from their infected counterparts. The larvae stay in the body of the intermediate host for 10 to 14 days and under favorable environment, get transformed into infective larvae. Now, when the mosquitoes bite a healthy dog, the infected larvae get injected into the dog’s or pet’s bloodstream. In the next 6 to 7 months, the larvae mature into adult forms and heartworm diseases symptoms start surfacing.
The symptoms vary based on the severity of infection, which is a combined result of key factors like – the number of worms living inside the dog (worm burden), duration of the infection, and how the dog’s body is responding to the presence of the heartworms. Symptoms are not so obvious in the beginning, but as the worm burden and duration increase they become prominent.
There are four classes, or stages of heartworm disease. The higher is the class, the worse is the disease and the more obvious are the symptoms.
If left untreated for long, the heartworm disease has a tendency to infect lungs, liver and kidneys a well, thereby leading to multi-organ failure, eventually causing death.
Is there a treatment for heartworm disease in dogs? Certainly, the medical science will not disappoint you. The official website of FDA claims arsenic-containing drug melarsomine dihydrochloride (available under the trade names Immiticide and Diroban) kills the adult heartworms, and Multi for Dogs (imidacloprid and moxidectin) can kill their larval forms, i.e. microfilariae.
However, refrain from administering these pet medicines on your own as the treatments often give rise to serious complications, such as life-threatening blood clotting in the blood vessels and lungs. A registered veterinarian after referring to an array of diagnostic reports, including X-ray and bloodwork can provide the right treatment course.
How to Prevent Heartworm in Dogs?
This is one of the most common questions that pet owners often ask. Many FDA-approved drugs are available that can help you keep your pet protected against heartworms. Consult to your dog’s veterinarian to decide the right preventive means. Injections, chewable and non-chewable oral prescribed medicines for dogs are available. Heartworm preventive medicines are also effective against roundworms and hookworms and external parasites such as fleas, ticks, and ear mites.