I’ve known more than a few rescue dogs that have had heartworm. It sounds really disgusting. Are they really worms that invade the dog, find their way to the heart and make their home there? Yes, that is a fact (invasion of the body snatchers!) According to the American Veterinary Medical Association (AVMA), “The dirofilaria immitis is a roundworm that travels from host to host through the blood, transferred by mosquitoes biting multiple victims. The worm itself is a filament-like, slim creature that completes its life cycle in mammals. In dogs, the adult heartworm takes up residence, sometimes for many years, in the right ventricle of the heart.”
Heartworm disease in dogs is treatable. While both cats and dogs are subject to heartworm, the illnesses and treatments are different for each. It is important to know the symptoms, causes and areas at risk and to be prudent in heartworm treatment. Although this disease was once confined largely to warm and wet areas, it has now spread globally.
So how can you tell if this gruesome creature has invaded your dog or cat? The symptoms of heartworm in dogs can be hard to diagnosis. Heartworm is a stealthy invader. Worms tend to accumulate gradually in the body, and clinical signs or other obvious symptoms may not appear for months after initial infection. Common signs of heartworm infection in dogs include the following:
Lethargy
Anorexia
Coughing (especially during physical exertion/exercise)
Reluctance to exercise/play
Rapid breathing
Weight loss
Heartworm symptoms may be undetectable after infection and through the early adulthood of the parasite, especially for sedentary dogs or dogs whose sedentary habits suggest age or fatigue. For active dogs, or dogs with a high rate of infestation, the most visible symptoms include cough, exhaustion after light exercise and cough during exercise. Occasionally, but rarely, heartworms may migrate internally and end up causing seizures in the brain, blindness or lameness.
Signs of heartworm infection in felines often mirror other more common respiratory ailments in cats so it’s important for a veterinarian to be consulted. Heartworm infected cats may exhibit many of the same symptoms that infected dogs display, along with allergy-like symptoms.
Pets should be tested at least once, possibly twice annually for heartworm infection through a simple and inexpensive blood test. The earlier heartworm is detected the better the prognosis for treatment. Canine heartworm sufferers are staged in levels I through IV based on the severity of the infection – it is much easier to treat a stage I infection than an advanced stage IV infection.
Heartworm diagnosis is carried out through a blood test for antigens secreted by female worms. For the blood test, a false negative can result if the worm population is low or if all the worms are males. Dogs that test positive for heartworm should have a heart X-ray to see the extent of the worm population in the heart itself.
Heartworm treatment is a prolonged process because adult heartworms take months to die. Dogs diagnosed with heartworm must be evaluated to make sure they are strong enough to withstand the treatment.
Veterinarians may require dogs to rest for several months after treatment to prevent dead worms from entering the lungs. Surgery to remove the worms is possible but is considered somewhat dangerous.
Lori Fusaro has been voted the best portrait photographer by FoxTV three years in a row and is a proud member of PPA and HeARTspeak. She lives in Culver City with her husband, four cats and dog. Contact: Lori@FusaroPhotography.com, FusaroPhotography.com. Follow her on Twitter: @FusaroPhoto.