How to Test for Heartworm at Home

What is Heartworm Disease?

Heartworm disease is a significant parasitic infection caused by Dirofilaria immitis, a nematode transmitted primarily by mosquitoes. Once inside the host, these parasites migrate to the pulmonary arteries and, in severe cases, to the heart, where they mature and reproduce. This condition is not only prevalent among dogs and cats but can also infect up to 30 other species of animals. The lifecycle of heartworms involves complex stages, beginning with the transmission of microscopic larvae through a mosquito bite and culminating in adult worms residing within the host’s circulatory system. The presence of these worms can cause serious health complications, potentially leading to fatal outcomes if left untreated.

Heartworm in Dogs & Cats

The impact of heartworm on dogs and cats is profound and varies based on the species. In dogs, which are natural hosts, the parasites thrive, causing severe cardiopulmonary issues that can escalate to life-threatening conditions if not addressed. The presence of adult worms in the pulmonary arteries and heart can lead to respiratory distress, liver dysfunction, and eventual heart failure.

Cats are atypical hosts, which means the heartworms usually do not survive to adulthood in a cat’s body. However, even immature worms can cause significant health problems such as heartworm-associated respiratory disease (HARD). Although less common, heartworm disease in cats can be serious, potentially leading to sudden death without any previous signs of illness.

Early detection and treatment are crucial in preventing the disease from causing irreversible damage to the organs. It’s important to note that the risks and outcomes of heartworm infection differ between dogs and cats, making regular testing and preventive care essential for both species.

Dogs & Cats Heartworm Symptoms 

In Dogs:

Heartworm disease severity in dogs depends on the worm burden, duration of infection, the dog’s response, and activity level. Less active dogs with a low worm burden may show minimal or no symptoms, while those with a higher burden or longer infection often display more significant signs.

The disease progresses through four stages:

• Stage 1: Mild or no symptoms, occasional coughing.
• Stage 2: Mild to moderate symptoms, including coughing and fatigue after moderate activity.
• Stage 3: Severe symptoms like persistent coughing, fatigue after mild activity, and signs of heart failure, often with visible changes in the heart and lungs on X-rays.
• Stage 4 (Caval syndrome): A critical stage where worms obstruct blood flow to the heart, requiring high-risk surgery, with a generally poor prognosis.

*Untreated heartworm disease can lead to severe organ damage and death, even if not all cases progress to the final stage.

In Cats:

Cats, on the other hand, may show more subtle symptoms or none at all until it’s too late. When symptoms do appear, they may include coughing, vomiting, and respiratory distress. Given the serious nature of heartworm disease in both dogs and cats, recognizing the signs early can make a significant difference in treatment outcomes.

Given these varied symptoms, it is crucial for pet owners to monitor their animals closely and seek veterinary advice if any of these signs emerge.

Heartworm Testing for Dogs & Cats

1. Testing Methods

Dogs Testing: Common tests include blood tests for microfilariae (the larvae) and antigen tests that detect proteins from adult female heartworms. A rapid-result test called a “SNAP” test can provide quick results from a small blood sample, typically within 5-10 minutes.

Cats Testing: Testing in cats is more complex. Veterinarians often use a combination of blood tests and imaging (like X-rays or ultrasounds) to detect heartworms, as cats rarely produce microfilariae.

2. Home Testing Options

For dogs, at-home testing can be an effective way to screen for heartworm. The Canine Heartworm Ag Rapid Test is a user-friendly option that allows you to test a dog’s blood for heartworm infection at home. This test provides results in about 5 minutes and requires only a small sample of blood.

Test Procedure:

• Collect a fresh blood sample from your dog.
• Place one drop of the blood into the test cassette, followed by three drops of buffer.
• Wait 5-10 minutes to read the results.

Interpretation of Results

• Positive Result: Indicates the presence of heartworm proteins or larvae.
• Negative Result: No detectable heartworm infection.
• Invalid Result: Results must be read within 15 minutes; otherwise, they are considered invalid.

3.Veterinary Clinic Options

For more comprehensive diagnostic needs, especially in cases where multiple infections are suspected, Shenzhen Gangzhu Medical Technology Company offers PCR test items. The kits, such as the Feline & Canine Heartworm Real-Time PCR Detection Kit, provide highly accurate detection of heartworm DNA. Gangzhu also produces multi-panel kits, like the Feline & Canine Zoonosis Panel (6 items), which screens for heartworm alongside other zoonotic pathogens, and the Canine Blood Parasites Panel (4 items), which includes tests for heartworm and additional blood parasites. These kits are particularly useful for veterinarians or pet owners looking for a thorough diagnostic approach.

Heartworm Medicine for Dogs/Cats

Prevention is the best treatment for heartworm disease in both dogs and cats.

For dogs, the FDA has approved several treatments, including Melarsomine Dihydrochloride (Immiticide and Diroban) for killing adult heartworms and Advantage Multi for Dogs (Imidacloprid and Moxidectin) for eliminating microfilariae from the blood. However, these treatments can be toxic and costly, often requiring multiple veterinary visits, tests, and injections.

Various FDA-approved products are available, most requiring a prescription for prevention. These are generally administered monthly, either as a topical liquid or oral tablet, with some products also protecting against other parasites like fleas, ticks, and intestinal worms. One product is available as an injection given every 6 or 12 months by a veterinarian.

For cats, there is no FDA-approved treatment for heartworm disease, although symptoms can be managed with medication. Surgery to remove adult heartworms is possible but risky, with potential complications such as shock and death. Therefore, prevention is also crucial for cats, with several FDA-approved products available that require a veterinarian’s prescription. These are administered monthly and may also protect against other parasites. Consulting with a veterinarian is essential to determine the best preventive measure for your pet.

Final Conclusion

Heartworm disease poses a serious threat to the health and well-being of both dogs and cats. However, with regular testing, such as that offered by rapid test kits and advanced PCR detection system, early diagnosis is achievable. Preventive measures, including consistent use of heartworm medication, are essential to protect pets from this potentially deadly parasite. By remaining vigilant and adhering to recommended testing and preventive schedules, pet owners can ensure their animals remain healthy and free from the dangers of heartworm disease.