My Dog Has Heartworms and I Can’t Afford the Treatment. What Should I Do?

Heartworms can be a death sentence for dogs. Heartworm preventatives sometimes lapse, and it’s not uncommon for adopted shelter pets to arrive at their new homes with a case of heartworms. The cost of heartworm treatment can be prohibitive, leaving some pet parents to wonder whether there’s an alternative. In this article, we’ll take a look at heartworms, and explain different types of heartworm treatments, including the slow kill method, which is usually the least costly.

What are Heartworms?

Heartworms are parasites that infect mammals including dogs, cats, foxes, coyotes, wolves, ferrets, and even sea lions. In some rare cases, heartworms have been found in humans, too. These nasty parasites are transmitted via mosquitos. They can grow to a length of about a foot long.

Adult heartworms produce offspring called microfilaria. These are circulated throughout the affected animal’s bloodstream. In the larval stage of life, these microfilaria are sucked up by mosquitos and transmitted to the next animal the mosquito bites. As they grow and multiply, heartworms cause lasting damage to the affected animal’s heart and lungs, along with other organs.

Dog Heartworm Symptoms

You won’t notice any symptoms during the early stages of a dog heartworm infestation – in fact, it takes about 6 months between the time of a heartworm infection and the time a dog tests positive for heartworms.

Even if your dog tests negative for heartworms and goes immediately onto a heartworm preventative, it’s possible to have a positive heartworm test at a later date. That’s why many veterinarians and rescue organizations recommend a follow-up heartworm test when a dog with an unknown health history has been adopted and placed on heartworm preventative.

Over time, as the worms grow larger and multiply, affected dogs usually develop a cough that’s caused by worms massed inside the heart and lungs.

Dogs with heartworm tend to tire quickly, often becoming winded in a short amount of time. Many infected dogs lose weight, as well.

As a dog’s heartworm disease progresses, the vet is able to hear audible changes in the lung sounds. Dogs with severe heartworm infestation are likely to retain fluid, which leads to a swollen abdomen. Some dogs pass out when the brain’s blood flow is restricted.

If a sudden blood flow blockage occurs, a dog with severe heartworm infection may also suffer from a form of cardiovascular collapse known as caval syndrome. Symptoms include pale gums, dark brown or bloody urine, and labored breathing. Surgery is the only option at this point.

Dogs with advanced heartworm disease have a poor prognosis for recovery, and damage caused by heartworms may cause poor quality of life even after treatment.

Dog Heartworm Disease Progression

When a dog tests positive for heartworms, most veterinarians conduct additional tests to determine how much damage ahs been done to the heart and lungs. Further testing can reveal whether the liver and kidneys have been damaged. There are several stages of heartworm infection as outlined below.

Stage 1 Heartworm Infection (Mild)

Mild heartworm infections are usually found in young, healthy dogs. Dogs with stage 1 heartworm infection have no symptoms, and X-rays show minimal changes.

Stage 2 Heartworm Infection (Moderate)

In stage 2 heartworm infection, it’s easy for vets to see evidence of disease on X-rays. These dogs have minor symptoms such as coughing or occasional shortness of breath.

Stage 3 Heartworm Infection (Severe)

Dogs with stage 3 heartworm infections usually exhibit a number of symptoms including coughing, shortness of breath or difficulty breathing, and weight loss. X-rays show clear evidence of damage to the heart and lungs, and many also show damage to the liver and kidneys.

Stage 4 Heartworm Infection (Critical)

Dogs with stage 4 or stage 5 heartworm infections often suffer from shock. These dogs are too weak to survive heartworm treatment. In critical heartworm infections, surgery is the only hope for survival.

Heartworm Treatment for Dogs

All heartworm treatments begin with restricting exercise. Physical activity can increase the rate of damage to your dog’s heart and lungs, so he will need to spend most of his time confined in a crate or a very small pen. In severe cases, your veterinarian many need to address other health issues such as underlying infections before moving on with heartworm treatment. This may take months to complete.

Fast-Kill Heartworm Treatment

There are three main methods of treating heartworm. The fast-kill method uses melarsomine dihydrochloride, which is also known as Diroban or Immiticide. This treatment begins with two injections spaced 24 hours apart.

As its name suggests, the fast-kill heartworm treatment starts killing heartworms immediately after administration. The worms decompose inside the dog’s bloodstream and are filtered via the dog’s lungs. This can lead to severe coughing, and in some cases, dogs die from blocked blood vessels or arteries. Physical exertion that leads to an increased heart rate and increase the chance of embolism. Dogs treated with the fast-kill heartworm treatment must be confined for four to six weeks to reduce the risk of elevated heart rate.

This treatment only kills mature heartworms. Most veterinarians recommend following up with Heartgard (ivermectin) or Advantage Multi (imidacloprid + moxidectin) for at least six months to a year, followed by an ongoing heartworm preventative regimen.

Staged Kill Heartworm Treatment

Also known as split-dose or three-dose heartworm treatment, the staged kill method consists of one injection followed by a wait of a month or longer, and then followed by two injections spaced 24 hours apart. The first injection can kill up to 50 percent of the heartworms. The remaining worms die when the last two injections are administered.

While this method is safer, it is also more expensive, and it means a longer confinement period for the dog. As with the fast-kill method, this treatment only kills the mature heartworms, so it’s important to follow up with Heartgard (ivermectin) or Advantage Multi (imidacloprid + moxidectin) for at least six months to a year, and then proceed with an ongoing heartworm preventative regimen.

Slow Kill Heartworm Treatment

The Slow Kill Heartworm treatment is gentler than other methods, but it can take up to two years to work, meaning that your dog is more susceptible to organ damage. This method simply involves consistent monthly treatment with Heartgard (ivermectin) or Advantage Multi (imidacloprid + moxidectin). This is a newer method for eliminating heartworms, and it is the most reliable heartworm treatment without paying a big vet bill.

This treatment may be recommended for dogs that can’t withstand the physical demands that fast-kill and staged-kill methods place on the body, and many veterinarians recommend it in cases where clients’ dogs have heartworm and other treatments are deemed unaffordable.

Heartworm Surgery

Surgical heartworm removal requires specialized instrumentation and training, so it’s not available everywhere. This method is very expensive, and it only removes adult heartworms, so additional treatment is required afterward.

Paratox and other Alternatives to Conventional Heartworm Treatment

There are other methods for killing heartworms, however there is no such thing as a safe DIY remedy. In all cases, the worms must decompose in the bloodstream, the dog must be confined, and he or she is still at risk of death by pulmonary embolism or organ failure. If you are interested in an alternative to conventional heartworm treatment, it is important to seek assistance from a holistic veterinarian.


In some severe cases, veterinarians recommend euthanasia for dogs with heartworms. This is only recommended when the prognosis is very poor, and when the dog is suffering. Euthanasia is a humane procedure that involves a simple injection of pharmaceutical agents that stop the pet’s heart quickly. In most cases, a sedative is administered beforehand, so the pet is sleeping peacefully before becoming unconscious. In most cases, the heart stops within 30 seconds of the injection. It is never easy to say goodbye to a beloved pet. Know that your veterinarian will only recommend euthanasia for heartworms when all other options have been exhausted.

The Importance of Heartworm Testing

Veterinarians recommend testing dogs for heartworm on an annual basis, even when pets are on an active heartworm preventative regimen. Without a test, it’s impossible to determine that heartworms are present until physical symptoms start to manifest. By the time symptoms are present, treatment is more difficult, and more expensive.

How to Prevent Heartworms

The best dog heartworm advice is this: In every case, it’s always easier to prevent heartworms than it is to subject your dog to treatment. Heartworm preventatives cost just a few dollars per month, and annual testing is affordable as well. You can choose between monthly pills or chews, or you can administer a topical heartworm preventative each month. In case you’re concerned about missing a monthly treatment, you can have your veterinarian administer an injection that lasts six months. There are a few herbal preventatives on the market, but these haven’t been proven to work as reliably as conventional heartworm preventatives.

If your dog has heartworms and you can’t afford the cost of treatment all at once, you may consider asking your veterinarian for a payment plan. Some vets offer this type of assistance, and others aren’t able to. There are also a number of organizations that offer help paying vet bills.