By Sherry L. Granader.
Some wise person once said, “An ounce of prevention is worth a pound of cure;” and nothing could be more true when it comes to 
protecting your precious dog or cat from heartworm disease.
The American Heartworm Society (AHS) defines heartworm disease as “a serious and potentially fatal condition caused by parasitic worms living in the arteries of the lungs and occasionally in the right side of the heart of dogs, cats and other species of mammal.”
While the cause of heartworm disease is simple (mosquito bites), the cure is difficult and costly. Dogs are more susceptible (100%) to becoming infected compared to cats where 61% to 90% will actually become infected.
According to Sheldon Rubin, 2007-2010 president of the AHS, all 50 states now have reports of heartworm disease. (Heartworm disease was once unheard of in Oregon, California and Arizona.)
Bad News/Good News
- Heartworm disease actually takes around 7 months to mature into adult heartworms.
- Adult worms can grow up to 12 inches, can live 5-7 years and reproduce as many as 250 worms in the host animal!
- It’s much more complex and difficult to diagnosis heartworm disease in cats than dogs.
- Animals cannot spread heartworm to each other or humans.
Preventing Heartworm in the First Place
Preventing heartworm in your pet is really easy and can be done by:
- Monthly pills;
- Monthly topical applied to the skin; or
- A six-month injectable.
Depending on your dog’s weight, a year’s supply of heartworm prevention will cost $35 – $80 according to pets.webmed.com.
Symptoms of Heartworm
One of the greatest dangers of heartworm is that, initially, there are no symptoms (remember, it takes 7 months for the worms to mature from the initial bite/infection.) By time there are symptoms, like a cough, the worms have already crowded into the heart and lungs. As the disease progresses, dogs can actually pass out from the loss of blood to their brain, begin to retain dangerous fluids, become lethargic and lose weight. If left untreated, most dogs will die.
Again, prevention more than outweighs the cure.
Curing Heartworm Disease
Unfortunately, with the lack of early symptoms, by the time dogs are diagnosed with heartworm disease, it is usually well-developed and will require two to three injections of an arsenic-based product (called Immiticide) to kill the adult worms in the blood vessels of the heart. While the treatment alone can be done for as little as $300 in some areas, the AHS says the safest – and most effective – way to treat heartworms completely includes extensive pre-treatment prep work including X-rays, blood work and tests to properly diagnose the severity and length of treatment.
Another difficult part of the treatment – during the months of treatment and then for several months after the treatment has ended – is keeping your dog quiet and not allowing them to even exercise. As the worms begin to die from the treatment, they break up into pieces that can become lodged in the pulmonary vessels and cause death.
Never use preventative in your pet without first testing for the presence of heartworm disease. Doing so could eventually kill your dog because the adult worms can still wreak havoc on your dog’s heart and lungs, even though the preventative may kill off younger worms.
Treatment of heartworm disease in cats poses a high risk of complications, and there is no approved treatment at this time according to the AHS.
So keep your pets healthy and safe from the potentially deadly heartworm disease by giving them year-round prevention!
Reviewed and approved by Dr. David L. Roberts, DVM
Photo: Courtesy of Courtney Nash via Flickr (CC by 2.0)
