How Do Dogs Get Heartworms?

Many dog owners take their veterinarian’s word as law. When our vet tells us how to best care for our pets, we certainly listen!

Something vets always recommend is heartworm medication. But have you ever wondered how dogs get heartworms?

Most cat and dog owners have heard of heartworms, but few know how they infect our pets and how serious heartworms can be.

Today, we’ll be looking at what heartworms are and how to keep our dogs safe.

What Are Heartworms?

Heartworms are a parasitic worm that can infest your dog. They don’t stop there though. Heartworm has been found in dogs, cats, and even ferrets.

Heartworm is a serious threat to our furry friends too. If an animal gets infected and it is left untreated, the parasite can cause damage to the animal’s heart, lungs, and large blood vessels. This is why the parasite is called “heartworm.” the mature adult parasites live in the dog’s heart and surrounding area. Each adult worm can grow to be twelve inches long, and one dog can be carrying hundreds of worms at a time. Simply the worm’s presence can cause your dog some real damage.

How Dogs Get Heartworms

The main culprit here are mosquitoes. A mosquito will bite an infected dog and take in the worm’s offspring called microfilariae. These offspring were born in the infected dog’s bloodstream, but they then grow into larvae in the mosquito over a period of about 10-14 days.

Once the microfilariae grow into their larval state, they are ready to infect another dog. The mosquito will bite another unsuspecting dog and the larvae will infect the dog.

The larvae will find the host very cozy and take their time maturing, usually about six to seven months. At that point, the adult heartworms have matured to adulthood and begin mating. Female heartworms will release microfilariae into the infected dog’s bloodstream, and the cycle will begin again.

One heartworm can live between five and seven years, so this cycle can take place many times if an infected dog is not treated. There some good news though.

Because of the way of how dogs get heartworms, if one of your dogs gets infected, they cannot pass it on to any of your other pets. Heartworms need that two-week period where the mature inside a mosquito. You never have to worry about you or your pets getting infected through contact with an infected dog.

What Are Heartworm Symptoms

To help note the severity of a dog’s infection, there is a classification for how severe their symptoms are. The classifications are as follows:

• Class 1 – Your dog may have a small cough or show no symptoms
• Class 2 – Your dog may cough more often or become easy to tire
• Class 3 – Your dog will develop a lingering cough and may become less coordinated. A dog will usually be very tired after light activity and have trouble breathing.
• Class 4 – This classification means the dog is laden with worms. There can be so many worms in the dog’s heart that blood has difficulty pumping. The only option at this point is emergency surgery to physically remove the worms. Even with surgery, most dogs pass away when their infection reaches this classification.

It’s important to remember that symptoms may not be completely obvious. Once a dog begins to show symptoms, they may be in real danger. If you suspect your dog is developing a heartworm infestation, be certain to take them to the vet as soon as possible. If left untreated, a heartworm infestation can damage your dog’s heart, lungs, liver, kidneys and will eventually lead to death.

How to Get Rid of Heartworms

If you suspect your dog has heartworms, take them to the vet immediately. Their first step will certainly be a blood test to confirm the presence of heartworms. Once heartworm has been confirmed, your doctor will begin to administer medication to rid your dog’s body of heartworms.

The only cure for heartworm is rather invasive though. Your vet will likely use a drug called melarsomine dihydrochloride. This drug contains arsenic which is poisonous to pretty much everything. The FDA does approve this medication for the removal of heartworms in dogs, but it’s important to remember that it is also toxic to the dog.

Injections of this medication can also cause blood clots in the dog’s lungs. They will also need multiple vet visits for follow up shots and blood work.

In all, while there is a cure, sometimes an ounce of prevention is worth a pound of cure. This is certainly the case for heartworms.

How to Prevent Heartworms

If you’ve ever had a dog before, you know that veterinarians will usually provide you with yearly heartworm medication. These are FDA-approved medications that assist in prevention. Each dose is taken monthly.

According to the FDA, “Both chewable and non-chewable oral tablets are available.  One product is injected under the skin every 6 months, and only a veterinarian can give the injection.  Some heartworm preventives contain other ingredients that are effective against certain intestinal worms (such as roundworms and hookworms) and other parasites (such as fleas, ticks, and ear mites).”

Puppies are just as susceptible as adults to getting heartworms. Therefore, preventative treatment should begin right away. Dosage for dogs is based on the weight of the dog. At yearly well-puppy exams, your dog should receive their year’s dosage heartworm medication.

Currently, there is no vaccine for heartworm. However, research is being done to see if this is possible. Therefore, for now, chewable heartworm medication is the only way to absolutely prevent it.

Getting Consistent Medical Support

The biggest takeaway from this is to get consistent medical support for your dog. If you can not afford heartworm medications, there are often ways to receive inexpensive or free vet treatments. Check your local ASPCA and vets for information on support.

We hope you feel more confident that you can prevent heartworm in your dog!