heartworm disease diagram.

If there is one pet problem that every owner should be aware of, the team at Leon Valley Veterinary Hospital thinks heartworm disease should definitely be in the top five. This deadly disease is very preventable, which makes education all the more important. Do you know how to prevent heartworm disease? If not, keep reading to find out.

What is Heartworm Disease, Anyway?

Heartworm disease refers to the infection of an animal (usually a dog, but cats are not exempt) with the parasite Dirofilaria immitis. These are actual parasitic worms that make their home in the heart, lungs, and associated blood vessels of their host. As you can imagine, this can have some pretty devastating results. 

Heartworms are transmitted in their larval state by mosquitos traveling from one animal to the next. Canids are the natural host and heartworm reservoirs can be present in wild animal populations such as coyote and fox.

A dog infected with heartworm may not have symptoms initially, but as the heartworms grow (up to a foot in length!) trouble can ensue. Symptoms of dog heartworm may include:

  • Reluctance to engage in activity
  • Coughing
  • Tiring easily
  • Decreased appetite
  • Weight loss

The longer heartworms have been present, the more likely there are to be symptoms. Eventually, congestive heart failure can occur. 

In cats, things are a little less clear cut. Because cats are not a natural host for heartworms, they tend to experience infection a little differently. Some infected cats may have a cough or asthma-like symptoms, while heartworm in cats might also look like sudden collapse. 

How to Prevent Heartworm Disease

Heartworm disease can be a very heartbreaking diagnosis (literally and figuratively). While we can treat it in dogs, the road to recovery is difficult and costly. In cats, we do not have any safe treatment options.

There is a silver lining, however. Heartworm disease is very preventable! 

It is important to understand the heartworm life cycle to understand how to prevent heartworm disease in dogs and cats. In the host, adult heartworms mate and have babies, called microfilaria. After about a week or two, these baby heartworms mature into larvae. Larvae are the infective form of the heartworm.

When a mosquito takes a blood meal from a host with infective larva in its bloodstream, they carry these larvae to the next host where they enter the bloodstream of the new animal through the mosquito bite. It takes about 6 months for these larvae to mature into adult heartworms. During the time this is happening, we are unable to detect infection.

Heartworm prevention works by killing the infective heartworm larvae. This means that each time you administer prevention to your pet, you are taking care of any disease that they have been exposed to in the previous month before a damaging adult infection occurs. 

Consistently and appropriately administered heartworm prevention is upwards of 98% effective. You can protect your pet by:

  • Using a recommended heartworm prevention regularly (talk to us about the best choice for your pet)
  • Eliminating mosquitoes in the environment as much as possible
  • Allowing us to screen for heartworm disease regularly as part of your pet’s wellness care

We might have a few mosquitoes in Texas, but that doesn’t mean that your pet needs to be at risk. Heartworm prevention is safe and effective and part of a good pet care plan.