Heartworm disease is a serious and potentially fatal condition caused by parasitic worms living in the heart, lungs and associated blood vessels of affected pets. It mainly affects dogs, cats and ferrets. Mosquitoes spread heartworm larvae to animals through bites. After infection, it takes about 6-7 months for adult worms to develop inside the animal and start reproducing. By the time clinical signs appear, the disease is usually quite advanced. The average cost of heartworm treatment ranges from $500 to $1000 or more, depending on the size of the dog, the stage of the disease, and the treatment protocol recommended by the veterinarian.
What are heartworms and how do pets get infected?
Heartworms are parasitic roundworms called Dirofilaria immitis that live in the heart and adjacent blood vessels of infected pets. They can reach lengths of up to 12 inches in dogs. Mosquitoes become infected with immature heartworms when taking a blood meal from an infected animal. Inside the mosquito, the larvae develop into the infective stage over 10-14 days. Then when the mosquito bites another pet, it injects the heartworm larvae into the animal’s skin. The larvae migrate through the body over several months, eventually reaching the heart and blood vessels. Here they mature into adult worms, mate and produce offspring.
Dogs are natural hosts for heartworms, so the parasites may survive and reproduce for years in their bodies. Cats are more resistant hosts, so worms often do not survive to maturity. But infected cats can still develop serious clinical signs. Ferrets are also susceptible to heartworm disease. The infection cannot be transmitted directly from animal to animal. Mosquitoes are required to spread the parasitic larvae.
What are the clinical signs of heartworm infection?
In the early stages, infected pets may show no obvious signs of disease as the juvenile worms migrate through the body. By the time the worms become adults and start reproducing, affected pets may demonstrate:
- A soft, dry cough
- Shortness of breath or tiring easily after mild activity
- Reduced appetite and weight loss
- Lethargy and generally appearing unwell
- Fluid buildup in the abdomen or lungs
In severe cases, symptoms may worsen to:
- Pale or blue gums
- Fainting or collapse
- Blood in urine or feces
- Sudden death
Cats with heartworm disease may show nonspecific respiratory signs like coughing, wheezing or difficulty breathing. They are also prone to vomiting, lethargy and weight loss.
How is heartworm infection diagnosed?
Diagnosing heartworm disease involves both looking for clinical signs and performing diagnostic tests. The veterinarian will take a thorough history and do a complete physical exam of your pet. They will listen to the heart and lungs for any abnormal sounds. Your veterinarian may also recommend:
- Blood tests to check for the presence of adult heartworm proteins or antibodies produced by the pet’s immune system in response to the parasite
- An echocardiogram (ultrasound of the heart) to examine the heart structure and look for signs of heart damage
- Chest X-rays to check for enlarged vessels or lung disease
- Complete blood counts to evaluate infection levels
These tests help confirm heartworm infection and determine the severity of disease in order to plan appropriate treatment.
What is included in heartworm treatment?
Heartworm treatment has two main steps:
- Killing the adult worms living in the heart and blood vessels
- Removing the dead worms from the pet’s body
Treatment may take several months to complete. It is tailored to your specific pet and overseen very closely by your veterinarian.
Medications to kill heartworms
There are currently three prescription medications approved by the FDA for eliminating adult heartworms:
- Melarsomine dihydrochloride
- Moxidectin
- Ivermectin
These drugs are administered by injection or orally. The regimen depends on the severity of disease and may include a combination of medications over 1-3 months. Several treatments may be needed to fully kill all the worms.
Blood thinners and anti-inflammatories
As the worms start dying, they break up and are carried through your pet’s blood vessels. This causes significant inflammation and potential blockages. To manage this, blood thinners like aspirin and anti-inflammatory drugs are given. Strict rest is enforced during this time to minimize the risk of complications.
Surgical removal of dead worms
Approximately 4-6 weeks after the last heartworm injection, your vet will re-check your pet’s blood for the presence of worms. Once they are satisfied the medication was effective, it’s time to remove the worm carcasses lodged in the veins. This requires a surgical procedure called a worm extraction or thromboembolism removal. General anesthesia is administered so the vet can insert a probe into the veins to extract the dead worms.
Hospitalization and monitoring
Your pet will need to be hospitalized at the veterinary clinic for most of the heartworm treatment. This ensures they can be continually monitored during the risky medication phase and recover properly after surgery. Blood work and other tests are run regularly to check for adverse reactions and confirm the worms are being eliminated. Your pet will be on IV fluids and may require pain medication as well as other supportive care.
What factors determine the cost of heartworm treatment?
Heartworm treatment is expensive because it’s a lengthy, high-risk process involving multiple steps of care. The total cost depends on several key factors:
Size of the dog
Larger dogs require higher dosages of medication and anesthesia, impacting the price. Generally, heartworm treatment costs:
- Under $1000 for small dogs under 25 lbs
- $1000-$1500 for medium dogs 25-100 lbs
- Over $1500 for large dogs over 100 lbs
Stage of disease
Dogs in the early stages of heartworm disease without significant heart or lung damage can undergo “slow kill” treatment with monthly heartworm prevention medication and antibiotics for around $500-600.
Dogs with moderate to severe infections need full adulticide treatment, which starts at $800-1000 or more. The more worms present and the more organs affected, the higher the risk of complications.
Diagnostic testing
Confirming heartworm infection with blood tests, x-rays and ultrasound costs $200-$300 on average. However, skipping these steps is not advised since treatment complications increase if the disease extent is unknown.
Hospital stay
The inpatient hospital stay for heartworm treatment often costs $40-$75 per night. This covers nursing care, monitoring and medications. Expect at least 2 weeks of hospitalization for most cases.
Surgical extraction
Removing dead worms following medical treatment runs approximately $200-$300 but may cost more with complications.
Medications
The drugs to kill adult heartworms are very expensive, especially for larger dogs. A single injection can range from $100-$500 depending on the dose. Pain relievers, antibiotics and other medications may be required too.
Location and veterinary fees
As with most veterinary care, location significantly impacts the total bill. Treatment at a specialty center is more expensive than a regular vet clinic. Fees also vary between veterinarians. Get cost estimates upfront.
| Dog Weight | Stage of Disease | Cost Range |
|---|---|---|
| Small dog (<25 lbs) | Mild infection | $800 – $1200 |
| Medium dog (25-100 lbs) | Moderate infection | $1000 – $1500 |
| Large dog (>100 lbs) | Severe infection | $1500 – $4000+ |
How to make heartworm treatment more affordable
Heartworm treatment is very expensive, often totaling over $1000. Here are some tips to make it a little more affordable for your budget:
- Have pet insurance – Many policies cover heartworm disease treatment, saving you thousands in medical bills.
- Apply for financing – Some veterinary clinics offer payment plans so you can pay for treatment in installments.
- Use a pet credit card – This allows you to pay the bill over time potentially with lower interest rates.
- Ask your vet about discounts for bundled packages – You may save some money by combining diagnostics and hospitalization.
- Inquire about financial assistance programs – Organizations like the Humane Society sometimes have funds available for sick pets.
- Consider lower-cost slow kill treatment if recommended – This is only appropriate for mild cases but can save a little money.
- Shop around – Compare quotes between veterinarians to find the best price, but don’t sacrifice quality of care.
While heartworm treatment is very expensive, skipping it can be fatal for your pet. Work with your vet to explore payment arrangements so you don’t have to delay this essential treatment.
Recovery and post-treatment outlook
With appropriate treatment, around 95% of dogs with heartworm disease can make a full recovery and live a normal lifespan. However, the severity of damage prior to treatment impacts future health and activity levels. After completing treatment:
- Exercise will be restricted for 1-2 months to allow heart and lung healing.
- Antibiotics may be prescribed for several weeks to prevent infection in damaged pulmonary vessels.
- Additional medications may be needed long-term if heart failure develops.
- Annual testing will be performed to check for new infections.
- Strict adherence to monthly heartworm prevention is essential.
In severe cases, even with treatment, some permanent damage may remain requiring long-term medication. But in most dogs, the prognosis is very good and heartworms can be successfully eliminated.
Prevention of heartworm infection
While treatment can be challenging and expensive, preventing heartworms is simple:
- Give your dog monthly oral or topical medication prescribed by your veterinarian. Options include ivermectin, milbemycin oxime, moxidectin, and selamectin.
- Many products combine heartworm preventives with flea/tick control for convenience.
- Cost is around $5-$15 per dose depending on the dog’s weight.
- Protection from a single dose lasts for 1 month. It must be continued year-round and never skipped.
- Have your dog tested annually to ensure the medication is working.
- Keep your dog away from standing water to reduce mosquito exposure when possible.
Following these steps will greatly minimize the risk of your dog developing a potentially fatal heartworm infestation. The few dollars spent upfront on prevention can avoid thousands in treatment down the road. Discuss the best heartworm prevention plan for your pet with your veterinarian.
Conclusion
Heartworm disease is a serious parasitic infection that can be life-threatening if left untreated. On average, treating a dog for heartworms costs $500-$1000 or more depending on the pet’s size, the extent of infection, diagnostics and hospitalization required, surgical care, medications prescribed, and additional factors like the veterinary fees. While the treatment is very expensive, it is lifesaving when performed properly under close veterinary supervision. The good news is heartworm infection is also very preventable with affordable monthly medication. Talk to your vet about the best prevention and treatment options for your canine companion. With appropriate care, most dogs recover well and continue to live happy, active lives after successful heartworm treatment.