Many pet owners are surprised to learn that heartworm disease in dogs is not spread from pet to pet. Instead, heartworms are transmitted by mosquitoes. In fact, it only takes a single infected mosquito bite to put a dog at risk.
Because mosquitoes are so common in Oklahoma, heartworm disease remains one of the most important preventable diseases veterinarians see. Unfortunately, many pet owners underestimate the risk, especially if their dog spends most of its time indoors.
How Do Dogs Get Heartworms?
Heartworms are spread through the bite of an infected mosquito. When a mosquito feeds on an infected animal, it picks up immature heartworm larvae. Those larvae develop inside the mosquito and can then be transmitted to another dog during a future bite.
Once inside a dog’s body, the larvae migrate through tissues and eventually mature into adult heartworms that live in the heart, lungs, and surrounding blood vessels. Adult heartworms can grow to more than a foot in length and may live for several years.
Why Are Indoor Dogs Still at Risk?
One of the most common misconceptions about heartworm disease is that indoor pets don’t need protection.
The reality is that mosquitoes regularly find their way into homes through open doors, garages, windows, and other small openings. If you’ve ever had a mosquito buzzing around your house, your pet has been exposed to the same risk.
Because it takes only one infected mosquito bite to transmit heartworms, even dogs that spend most of their time indoors can become infected.
Signs of Heartworm Disease
Heartworm disease often develops slowly, and many infected dogs show few signs during the early stages. As the disease progresses, symptoms may include:
- Coughing
- Decreased energy
- Exercise intolerance
- Difficulty breathing
- Weight loss
- Reduced appetite
In severe cases, heartworm disease can cause heart failure, lung damage, and life-threatening complications.
Prevention Is Far Easier Than Treatment
The good news is that heartworm disease is highly preventable.
Monthly preventatives and long-acting prevention options are designed to stop heartworms before they can mature and cause damage. Consistent, year-round protection is the safest way to keep pets protected, especially in areas where mosquitoes remain active for much of the year.
Many owners are surprised to learn that treating heartworm disease is significantly more difficult, expensive, and risky than preventing it. Treatment requires multiple steps, strict activity restriction, and months of careful management. Even after successful treatment, some damage to the heart and lungs may be permanent.
Why Annual Heartworm Testing Matters
Even pets receiving prevention should be tested regularly. Annual heartworm testing helps ensure that prevention programs are working as intended and allows veterinarians to identify infections before significant disease develops.
Early detection can make a tremendous difference in treatment options and long-term outcomes.
Protect Your Pet Year-Round
Heartworm disease in dogs is serious, but it is also one of the most preventable conditions we see. Because mosquitoes can be found both indoors and outdoors, every dog is potentially at risk.
If your pet is not currently on heartworm prevention or is due for annual testing, the Family Animal Medicine team can help. A simple conversation today can help protect your dog from a disease that starts with something as small as a mosquito bite.