What Pet Owners Need to Know About Heartworm

Heartworm is a parasitic roundworm. Sometimes also known as dog heartworm, discussion is caused by parasites transmitted through mosquito bites, and is a serious condition that requires immediate attention. Usually, heartworms reside in the heart of an animal, but they can also be found in tissue and organs like the brain, kidneys, and lungs. Given that such a parasite can harm your pet’s health immensely, it is important to familiarize yourself with heartworm as a pet parent. 

Here Are A Few Things Pet Owners Need to Know About Heartworms

What is Heartworm? 

Heartworm is an infectious parasitic disease, transmitted from the bite of a mosquito which is carrying the parasite. The "worm" in such mosquitos starts as microfilariae, which is their early stage of development. Once fully mature, these microfilariae then develop into larvae which are spread when the mosquito bites another animal like your dog/cat.

 Since heartworm is a vector-borne disease (spreads through the bite of a host vector), it can spread to several different animals like dogs, cats, ferrets, foxes, and raccoons. This mode of transmission also means that indoor-only pets are not safe either, as the disease-carrying mosquitos can easily enter a home. 

Heartworm in Dogs 

Heartworm is a serious condition in dogs, with thousands of dogs testing positive for it yearly. The parasitic larvae can mature and reproduce within a dog, and their lifespan of 5-7 years means they can live inside your dog for a long time.

Heartworms are a serious issue and must be addressed immediately. However, it is difficult to do so, as infected dogs may not exhibit any symptoms for some time. This is why annual testing for heartworms and other parasites, as testing can help identify these pests promptly and allow preventive treatment to begin quickly. 

Heartworms can be tested for through a blood test. You can inquire about parasite treatment on a vet visit. During a blood test, your vet will check for antigens which are produced by adult heartworms, as well as any microfilariae that may be present in their system. 

Heartworm has a few stages in dogs: 

Stage 1 – Mild symptoms like a light cough may be visible.  
Stage 2 – Mild to moderate symptoms like quick exhaustion are visible. 
Stage 3 – Symptoms gradually become more severe, with persistent coughing and signs of heart trouble. 
Stage 4 – The large number of worms in the dog’s heart block blood flow; also known as caval syndrome, it can only be treated through a risky medical procedure, with fatalities remaining high despite it at this stage.

The first three stages can be treated; they require lengthy administration of oral steroids and antiparasitic injections. Some medicines deal with the presence of microfilariae as well. During the treatment period, activity must be curbed significantly, and steroid administration must continue for multiple weeks. 

The treatment process & medication involved also may have some visible side effects as well. Given that treatment is complex, expensive, and comes with side effects, it is best to implement preventive action to avoid the happenstance of an infection. 

Heartworm in Cats 

Like dogs, cats can also be infected by heartworms; however, they affect them differently. Unlike dogs, cats are not the perfect host for heartworms. In cats, heartworms do not grow to be as the ones in dogs, and they don’t live for as long either. Such heartworms in cats also die before maturing fully more often in cats. This may sound positive, but cats are also smaller in size compared to dogs, meaning such parasites can still be dangerous. 

Cats show generalized symptoms during heartworm infections like vomiting, loss of appetite, and weight loss. Cats who show symptoms will eventually become symptomatic, which happens when the heartworms have matured over 2-4 months and entered the heart. They will also show symptoms like respiratory issues. The inflammation caused by heartworm-associated respiratory disease can be fatal due to the lung damage it causes. 

In cats, heartworms are much harder to detect through blood tests. So, unlike dogs, cats require X-rays and heart ultrasounds to detect the presence of heartworms. Symptoms can be controlled somewhat with treatment, but since there is no perfect cure and surgery is hit-or-miss, prevention is still a far better alternative than a cure. 

Preventing Heartworm 

Since treating heartworm is expensive, difficult, and often dangerous, preventing it is the easier course of action. Dogs should be tested for heartworm annually, and all pets should be given preventive medication against heartworms monthly. Such medication comes in a few forms, with oral tablets, lotions, or injections. Do note that these are preventive measures and will not alleviate an existing infection. 

To conclude, heartworm is a dangerous parasite that spreads through mosquito bites. Due to its nature and potential to cause serious bodily harm, it is important to implement preventive measures and medication. Their dangerous nature is one of the reasons some countries require internal and external parasite treatments before any international pet transportation. However, with caution and preventive measures, you should have no trouble keeping your pet free from heartworm. Make sure to visit your vet and obtain a preventive treatment as you do so.