Guarding Your Pet’s Heart from Heartworms
Weeks after Tony found the German Shepherd puppy he named Shep, he noticed that the dog coughed after their runs in the park. Shep was also thin, but Tony thought that was a result of his being out on his own for some time.
Tony would soon find out from the veterinarian that Shep was suffering from heartworm infestation—a parasitic infection with subtle early signs that could be easily overlooked.
What Are Heartworms?
All animals can be susceptible to parasitic worm infections from food, water or insects, and examples of parasitic worms include hookworms, roundworms, pinworms, tapeworms and heartworms. Parasitic worms live off their hosts and can cause enough damage to eventually kill the animal.
Heartworms are spread by mosquitoes and can affect dogs, cats, ferrets and other animals. They are called heartworms because they eventually end up in the heart where they can live for years before killing the animal with heart failure.
When a mosquito that is carrying heartworm larvae bites a dog, it transmits the infection. The larvae then grow and migrate throughout the animal’s body until they mature, which can take up to a year after infection, when they end up in the heart, lungs and related blood vessels of the animal. Female heartworms can grow up to 12 inches. The heartworm’s lifespan can be as long as 7 years in a dog.
What Are the Signs of Heartworms?
Recognizing signs of heartworm infestation may not be easy as the early signs may be subtle or nonexistent. Some signs may be coughing, especially after exercise, weight loss, or coughing up blood. Sometimes the worms migrate to different areas and cause other problems like seizures or blindness. Often signs can be so slight or missed that the condition may not be recognized until it’s too late—when the animal has suffered heart failure.
That’s why veterinarians recommend that the best defense in heartworm prevention is a good offense—that is, first ruling out heartworm infection with diagnostic tests and then maintaining a routine prevention program.
How Are Heartworms Treated?
Heartworm treatment has evolved over the years, and many dogs can be successfully treated for the infection.
Dogs with mild infection are typically better positioned for a successful recovery. Dogs with more severe infection have greater risk for complications or death. Because there is some risk to the dog with potential side effects of the heartworm treatment as well as health complications from a large die off of heartworms, your dog’s best bet is to have a strong health care routine recommended by your veterinarian that includes routine vaccinations as well as a heartworm prevention program.
Can Cats Get Heartworms?
Years ago, experts thought that dogs were far more susceptible than cats to heartworms, but more recent research shows that though cats have smaller and fewer heartworms than dogs, they can suffer from the damage that heartworms causes them. Heartworms cause damage to internal organs in cats even in the larvae stage. In fact, according to the American Heartworm Society, cats can suffer from a newly recognized syndrome called heartworm associated respiratory disease, which is often misdiagnosed as asthma. Other signs in cats may be vomiting, lethargy, no appetite or weight loss. Like dogs, however, signs may be subtle or lacking and cats can die suddenly before the signs were even recognized.
At this time, there is no treatment for heartworm disease in cats, which is an especially good reason why cats should be on a prevention program. Medical treatment of cats with heartworms is usually for supportive therapy, which addresses the actual damage done by the heartworms (for example, prednisone or bronchodilators for lung disease resulting from heartworm infection). Sometimes surgery may be required for manual removal of heartworms that are obstructing blood flow in major vessels.
How Do I Protect My Pet from Heartworms?
Heartworm prevention medicines are available for dogs and cats and may be in tablet, chewable, topical or injection preparations; some are given monthly. Some examples are Heartguard, Interceptor and Revolution. Some preparations have additional benefits of killing other types of parasitic worms. Check with your veterinarian as to which formula is best for you and your pet. He or she will recommend a diagnostic blood test to first rule out heartworm infection. Then you can begin your pet’s heartworm prevention program.
As for Shep, he was successfully treated for heartworms, and Tony makes sure that Shep is on a full preventative health program that includes a monthly heartworm medication.