Heartworms, Pets & People
Heartworms and Your Pet
Heartworms are known to occur throughout the U.S., and though they have been preventable for decades, they are still common in dogs and cats. Transmitted by mosquitoes, they are among the most damaging canine and feline parasites. Heartworms are transmitted by feeding mosquitoes and, once mature, take residence in the heart and large vessels of the lungs.
Heartworms can be a very serious problem for both dogs and cats, especially those in mosquito infested areas. Because heartworms live in the bloodstream, lungs and heart, they can kill or seriously debilitate pets that are infected with them.
See Your Veterinarian
Your veterinarian can conduct a simple blood test to determine if your pet has heartworms or heartworm disease. Diagnosis in cats can be more challenging. A year-round preventive program is recommended by authorities and is most effective to keep pets free of heartworms.
Common questions about heartworms
Should I be concerned about heartworms in my pet?
Yes. Heartworms are transmitted by the bite of mosquitoes from an infected pet. They must go through the mosquito, not directly from dog to dog. Heartworms can kill or seriously debilitate pets that are infected with them. That’s because heartworms live in the bloodstream, lungs and heart of infected pets.
How will heartworms affect my dog?
The heartworm larvae deposited by the feeding mosquito eventually migrate to the chambers of the heart or into the vessels of the lungs. Once in the heart, the worms can affect blood flow throughout the body. Heartworms may be up to a foot long and your pet may have anywhere from one to several dozen in their heart and adjacent blood vessels.
Heartworm infection can affect many different organs of the dog. While the heart and lungs may suffer most, other organs such as the kidneys and liver may be impacted. A veterinarian may suspect that an animal has been infected if an active animal tires easily or shows shortness of breath or coughing; however, one or more tests conducted by your veterinarian may be necessary to determine whether or not your dog has heartworms. There may be no signs at all. This makes testing and prevention all the more important to do before signs begin.
Can my cat be affected by heartworms?
Yes. However, feline heartworm disease can differ significantly from its canine counterpart, and may require the use of several diagnostic tests or procedures to confirm a diagnosis. Cats with clinical heartworm disease usually present with respiratory signs such as coughing and/or difficulty breathing, or even intermittent vomiting not associated with eating. Other signs include weight loss and/or diarrhea without accompanying respiratory signs. The respiratory signs are difficult to differentiate from those observed with feline asthma.
How do I prevent my pets from getting heartworms?
All dogs and cats are at risk, even those animals that primarily live indoors. However, heartworms are preventable.
Ask your veterinarian about heartworm prevention. Preventive treatment should begin at six or eight weeks of age in puppies and after tests have been conducted in older dogs to determine if your dog has already been infected. If your dog does have heartworms, your veterinarian can advise you about treatment options. In dogs over six months of age, a blood test is recommended before starting medication.
Tips to protect your family and your pet.
Wash your hands well after contact with an animal.
- Do not allow children to put dirt in their mouths.
- Pick up dog and cat waste from your yard daily, especially in areas where both children and animals play.
- Cover home sandboxes to protect them from fecal contamination.
- Have your pet tested regularly (one or two times a year) for parasites by a veterinarian and administer year-roundpreventive medications to control internal parasites that present a risk to your pet and your family.
Why should I control parasites for my pet year-round?
Isolated cases of human infection have been reported, but heartworm is generally not considered a risk to human health. However, due to the large number of internal and external parasites and the high risk of pet infection, controlling parasites year-round is the most reliable way to ensure the highest level of health for your pet and well-being of your family. Year-round prevention is the most effective way to control cat and dog parasites and the diseases they can carry.
The Companion Animal Parasite Council
The Companion Animal Parasite Council (CAPC) is an independent council of veterinarians and other heath care professionals established to create guidelines for the optimal control of internal and external parasites that threaten the health of pets and people. It brings together broad expertise in pararsitology, internal medicine, human health care, public health, veterinary law, private practice and association leadership.