Winter Heartworm Prevention

Cold Weather Does Not Protect Pets from Parasite

Heartworm disease is a serious and potentially fatal condition in dogs and cats and is transmitted by mosquitoes.

Because we tend to notice mosquitoes during warmer months, we associate heartworm disease as a summertime threat.

Pet owners, take notice: Heartworm disease can affect our pets at any time, even during winter months, which is why it is important to continue preventive treatment year-round.

What is Heartworm Disease?

Heartworms are caused by bites from infected mosquitoes that carry microscopic baby heartworms into the bloodstream. After your pet is bitten by an infected mosquito, it takes up to six months for worms to grow to adulthood inside your pet’s lungs.

Adult worms are about the size of a piece of spaghetti and by living in the blood vessels in the lungs and heart, cause difficulty with blood flow and damage to both organs. The disease manifests somewhat differently in cats and dogs, but the key is that prevention works for both.

Heartworm Exposure

Limiting your dog or cat's exposure to mosquitoes, even if your pet is on preventive treatment, will help reduce the chance of infection.

Mosquitoes are particularly drawn to water, although this is not the only way your pet could be exposed. Swampy water, ponds, pools and water collected in bird baths or other containers can attract mosquitoes.

If mosquitoes are especially bad in your area, bring your pets inside at dusk when mosquitoes tend to be out and consider using a topical, vet recommended spot on product on dogs (not available for cats) that will help repel mosquitoes along with fleas and other pests.

Heartworm Disease Symptoms

The most common clinical sign of heartworm disease usually is no sign at all until the disease is well advanced.

Progressive signs may include chronic coughing, unwillingness to exercise, tiring easily and lethargy, difficulty breathing and an enlarged abdomen in dogs, and coughing and asthma-like symptoms in cats.

By the time your dog or cat shows signs of heartworm disease, damage to the lungs has already occurred. There is a treatment available for dogs, although the treatment itself poses some risks. There is no treatment for the disease in cats and they must be managed medically to maintain quality of life.

Testing for Heartworms

Veterinarians recommend an annual test that detects the presence of heartworms so that your pet can be treated before showing clinical signs of the disease.

The antigen test will detect the presence of protein molecules from adult heartworms in the bloodstream. A second test looks at a small amount of blood under a microscope to check for the presence of immature heartworms. There is a third blood test that checks for the body’s immune response to the heartworm and this test is sometimes used in cats.

If your dog tests positive for heartworms, aggressive treatment will be required prior to taking a monthly preventive.

Preventing Heartworm Disease

Fortunately, a monthly pill or topical solution, prescribed by your veterinarian, can be given to dogs and cats to prevent heartworm disease.

Mosquitoes can live in your house for an extended period of time, and you can never be sure exactly when mosquitoes die off in the cold and come back in the spring. If your dog or cat is bitten by a mosquito during spring or summer months, the heartworms will continue to grow well into winter months, hence the need to continue preventive treatment.

Stay one step ahead of this potential threat: Protect your pets from heartworm disease by limiting exposure and providing preventive treatment year-round, even during those chilly winter months.