Vet Blog

10 Things You Need to Know about Heartworms and Your Dog

April 30, 2019

April is heartworm awareness month.

Despite being a common parasite that affects around 1 in every 200 dogs each year, many owners still don't know a great deal about the disease and the effects that it can have on their furbaby.

To help improve your knowledge and enable you to feel prepared should your furbaby become affected, here are the 10 things that you most need to know about heartworms and your dog.

1. Heartworms Are Spread by Mosquitos

Many people think that all internal parasites are spread through eating raw or rotten food. Not the case with heartworms which are transmitted by the humble, if annoying, mosquito. When a mosquito takes blood from an animal carrying the disease, they act as an intermediate host, incubating the larvae and then transferring them when they next take a meal. These larvae are known as microfilaria. Currently, it is estimated that around 30 species of mosquito can act as intermediate hosts for heartworms.

2. All Dogs Need Protecting against Heartworms Regardless of What State They Live in

Heartworms may be more common in the warmer states, but evidence of the disease has been found in all 50 U.S. states. This means that there are no geographical boundaries for mosquitos and nowhere can be classified as 'no risk' of heartworms. For this reason, vets advocate prevention for all dogs regardless of where they live.

3. It Takes Six Months for Heartworms to Mature into Adults

Once your pet has been infected with microfilaria it takes around six months for them to mature into adults. During this time, they are traveling through your dog's bloodstream to her lungs, her heart, and the large blood vessels around them. This is where the worms will live as adults.

4. Heartworms Can Be Huge, and Females Are Bigger than Males!

The thought of any sort of worm can be enough to gross some people out. However, heartworms aren't just like regular worms. They may only be around 5mm thick, but males can grow up to 6 inches long while females have been found to reach more than a foot in length! Once fully grown, heartworms closely resemble noodles or cooked spaghetti. It is not unheard of for a dog to have as many as 250 worms living in its body (known as a worm burden).

5. The Symptoms of Heartworms Can Be Difficult to Recognize

Dogs are exceptionally talented at hiding vulnerabilities, such as illness or weakness. This combined with the fact that it takes around 6 months from being bitten for symptoms to manifest means that it may be hard to realize that your canine pal has been infected with this parasite. When symptoms do show, they are fairly subtle and will include:

  • Unwillingness to exercise
  • Coughing or fainting after exercise
  • Persistent dry cough at all times
  • Difficulty breathing
  • Lethargy / lack of interest in doing anything
  • Poor appetite
  • Weight loss
  • Dull coat quality

6. Left Untreated, Heartworms Can Cause Caval Syndrome

Caval Syndrome is the name given to a scenario whereby a dog's worm burden is so large that their blood flow is physically blocked by a large mass of worms and cannot travel to the heart. This is an emergency scenario that requires surgical removal of the worms from your pet's body. Unfortunately, this is highly risky surgery and a large number of dogs still do not survive. Those that do will have permanent damage to their major organs including the heart, lungs, liver, and kidneys.

7. Dogs Can Be Treated for Heartworms, but Not without Considerable Risk and Cost

While it is very fortunate that dogs with heartworms can be treated, the process does carry a number of different risks. These include a risk of blood clots as well as reaction to the death of the heartworms themselves. For this reason, your canine will be very closely monitored throughout the course of the treatment. As you might expect, the cost of heartworm treatment is also expensive - around 15 times more costly than preventing the parasite in the first place.

8. Prevention Is Better than Treatment

It goes without saying that it is far better to prevent your pet from having heartworms than having to treat it. There are lots of different preventatives available, including topical 'spot-on' style applications, oral tablets, and even an injection. Since all heartworm preventatives have to be prescribed by a licensed professional, your vet will advise you which is best for your canine companion.

9. Preventatives Must Be Given on Time Every Time

Each preventative is only effective for the period of time stated on the manufacturer's guidelines that are supplied with it. In most cases, this is 30 days. In the case of injectable preventatives, it is six months. It is essential that you stick to this schedule and administer each dose on time. Failing to do so could leave your dog at risk of the disease.

10. Your Veterinarian Is Your Best Support for Anything to Do with Heartworms

If you have any questions about heartworms, their prevention, or treatment, your veterinarian is the best person to speak to and will give you the latest advice. If you would like more information, our friendly and experienced staff at Safe Harbor Animal Hospital would be happy to help. Please contact us at our animal hospital in Pensacola, FL by calling us today at (850) 476-5571.

We know that sometimes with pets, the unexpected happens. That's why, in addition to well pet visits, we also provide same-day urgent care/sick patient visits. Call us to verify availability today!