7 Myths About Heartworm Disease

Heartworm disease is a preventable, but serious and potentially fatal disease caused by a blood blood-borne parasite called Dirofilaria immitis.  It primarily affects dogs, cats and ferrets, although it can affect a variety of wild animals such as foxes, wolves, coyotes and more.  It takes just one bite from a mosquito infected with heartworm larvae to jeopardize your pet’s health and welfare.

Unfortunately, there are a lot of myths and misunderstandings that are widespread about heartworms.  Don’t fall for these common myths about heartworm disease.  It is important to your dog’s health to keep your dogs on heartworm prevention all year around and have the annual blood test to be sure the heartworm prevention is working:

Myth #1: Heartworm Disease is Rarely Fatal

Not True!  Heartworm disease is a devastating (preventable) and potentially fatal disease, impacting a pet’s heart, lungs, and pulmonary blood vessels.   

In dogs, symptoms of heartworm disease are:

• Coughing
• Fatigue/Lethargy
• Difficulty breathing
• Weight loss, lack of appetite

In cats, symptoms of heartworm disease are

• Lung disease
• Respiratory distress
• Chronic coughing
• Vomiting 

Myth #2: Only outdoor pets get heartworm

Outdoor dogs are more likely to be bitten by mosquitoes, but remember that mosquitoes come into our homes through open doors and windows.  Also remember that just because you do not notice mosquitoes inside your home, it does not mean they are not present.  All pets are exposed whether they are inside or outside.

Myth #3: Mosquitoes are only active in warm months

Freezes do kill adult outdoor mosquitoes, but their eggs are tough and are able to ride out extreme temperatures.  Mosquito eggs can lie dormant for up to two years before hatching when ideal conditions present themselves.  Midwest winters fluctuate, and can present weather days with snow one week and be 80 degrees the next.  Protecting your pets through fluctuating weather is important.

Myth #4: Heartworm Disease Only Occurs in Wetter Climates 

Heartworm disease has been reported in all 50 states.  Mosquitoes are highly adaptable and will find other places to breed, even during a drought. They will search out watered lawns, gardens, birdbaths, standing water or underground storm systems during times of drought.  Other areas with standing water, including ponds, lakes, and swimming pools, can provide optimal breeding conditions for mosquitoes.

Myth #5: Only Dogs Get Heartworm Disease

Dogs are the companion animal most at risk for heartworms, but cats and ferrets are vulnerable, too. Ask your veterinarian whether they recommend heartworm prevention for your pet.  Like dogs, cats can develop heartworms, but it’s more common for heartworms in cats to die before they reach full maturity. 

Myth #6: An Annual Heartworm Test Is Not Necessary If an Animal Is on Preventives

An annual blood test is the safest, and recommended way, to give you the peace of mind your pet’s preventatives are working.  

 Myth #7:  It’s Ok to Miss a Dose of Heartworm Protection

We all can forget to take our medication, but missing just one dose of your pet’s monthly heartworm medication can leave your dog unprotected.  Also, be vigilant that your dog does not spit out their heartworm pills when you are not looking or rub off their topical medication.  Skipping a month can lead to infection.  If a monthly dose is missed, a dog should be tested for heartworm six months later.

We would be happy to answer any questions you might have about how to best protect your pet from heartworm disease!