Vet Blog

Heartworm Basics

April 18, 2019

As caring and committed pet parents, we are dedicated to keeping our animals safe from the multitude of different diseases that can affect them.

One of the parasites that pose the biggest risks to pets, and in particular dogs, is heartworms.

April is heartworm awareness month here in the U.S. To help you be as informed as possible, here is everything that you need to know about heartworms, including how to keep your precious furbaby safe from this potentially deadly condition.

What Are Heartworms?

Heartworms are a blood-borne parasitic infection that occurs all over the world. While dogs are the natural host of this parasite, it can also affect domestic cats and ferrets. Wild animals including foxes and coyotes can also suffer from heartworms.

Heartworms are transmitted through the bite of an infected mosquito. Currently, there are around 30 species of mosquito that can transmit heartworms. If the mosquito that bites your pet is carrying heartworm disease, it will transfer some microscopic heartworm larvae known as microfilaria, into your pet's bloodstream. Here it will migrate through her body until it reaches the heart and lungs and associated blood vessels where it will grow and mature. Adult heartworms can reach up to 12 inches in length. Once mature, heartworms can reproduce. This enables the number of worms inside an infected pet to continue to grow. Severely infested pets have been found to have as many as 200 foot-long worms in their body.

Why Are Heartworms So Dangerous?

Heartworms have a reputation as one of the deadliest types of parasitic infection and with good reason. Unless treated, the number of worms inside your pet's body will continue to grow, clogging up the blood vessels and causing permanent, irreparable damage to her main organs and overall health. Animals who do not receive treatment for heartworms will almost certainly suffer from heart failure and pass away. Prompt diagnosis and treatment of heartworm disease are essential if your dog is to make a full recovery.

It is important to note that heartworm disease is very different in cats than in dogs. Since cats do not make good hosts for heartworms, the microfilaria often does not survive to adulthood. If a cat is found to have adult worms, typically they will only have two or three-foot-long worms in their body. However, immature heartworms can still cause damage to your pet's respiratory system in a condition known as heartworm-associated respiratory disease or HARD. Since the medication used to treat heartworms in dogs cannot be used in cats, prevention is the only true way of keeping your feline friend safe from the condition.

Can Animals Pass Heartworms Between One Another?

The only good news is that heartworms can only be transmitted by mosquito bites. This means that if you have one dog with heartworms, you don't need to worry about her passing it to your other pets.

What Are the Symptoms of Heartworms?

Animals are very good at masking illness which can make it tricky to diagnose illness, particularly when symptoms of a condition are subtle. Nevertheless, symptoms of heartworms include the following:

  • Breathing problems
  • A soft cough
  • Lethargy
  • Unwillingness to exercise
  • Weight loss
  • Poor coat quality

What Is the Treatment for Heartworms?

Fortunately, heartworms can be treated effectively, and modern medications mean that treatments have a success rate of around 95%. The most common treatment is an injectable drug that kills the adult heartworms that are present in the heart and adjacent blood vessels. However, it is important that your veterinarian doesn't kill all the heartworms at once as this could cause your pet to go into shock. Therefore, the injections are divided into multiple doses given approximately 30 days apart. This allows your pet's body to safely eliminate all the dead worms from the first dose before moving on to the second. In addition to this, many vets in Cleveland, TN will also advocate the use of an antibiotic which will help to prevent any infection from the bacteria that are contained within the heartworms.

Depending on how badly your dog has been affected, it may also be necessary for your vet to provide other treatments to aid his recovery. This could include intravenous fluids, heart medications, beta-blockers, or a special diet.

Heartworm Prevention

Of course, it would be much better to prevent your animal from ever having to fight a heartworm infestation. This is possible thanks to successful preventative medications. There are a range of different products available and your veterinary team will be happy to help you find the one that is most suitable for your pet. As with all preventatives, these should be administered on a strict schedule so that there is no point where your furbaby is left vulnerable to the disease.

In addition to preventatives, many veterinarians also recommend yearly screening for heartworms. This is usually included in or recommended during an annual wellness exam. This gives owners additional peace of mind that their precious pet is completely safe and free from this potentially deadly disease.

If you have more questions about heartworms, or if you are concerned about your pet and would like to schedule an exam with our veterinarians in Cleveland, TN, call us at (423) 479-4760 to get in touch with our experienced team at Appalachian Animal Clinic today.