What should I do if my dog tests positive for heartworm?

If your dog tests positive for heartworm, it is essential to take immediate action to address this serious and potentially life-threatening condition. Heartworm disease is caused by the parasitic worm Dirofilaria immitis, which is transmitted through mosquito bites. The worms mature and live in the heart, lungs, and associated blood vessels, causing severe damage over time. Below is a detailed guide on what to do if your dog tests positive for heartworm, including treatment options, risks, and long-term care.

1. Confirm the Diagnosis
The first step is to ensure the diagnosis is accurate. A positive result from a heartworm antigen test should be followed by additional testing, such as a microfilaria test or imaging (e.g., X-rays or ultrasound), to confirm the presence of adult worms and assess the extent of the infection. Your veterinarian will guide you through this process.

2. Stabilize Your Dog
If your dog is showing severe symptoms, such as coughing, difficulty breathing, or lethargy, your veterinarian may recommend stabilizing your dog before starting treatment. This could involve medications to reduce inflammation, improve heart function, or address secondary infections. In advanced cases, hospitalization may be necessary.

3. Begin Heartworm Treatment
The standard treatment for heartworm disease involves a series of injections of melarsomine, an arsenic-based drug that kills adult heartworms. The treatment protocol typically includes:
a. Pre-treatment evaluation to ensure your dog is healthy enough for the injections.
b. Administration of an adulticide (melarsomine) in two or three doses, spaced several weeks apart.
c. Strict exercise restriction during and after treatment to minimize complications, as physical activity can increase the risk of blood clots from dying worms.

4. Address Microfilariae
In addition to treating adult worms, your dog may need medication to eliminate microfilariae (immature heartworms) in the bloodstream. This is usually done after the adult worms have been treated to prevent further complications.

5. Manage Side Effects and Risks
Heartworm treatment carries risks, including allergic reactions to dying worms, blood clots, and organ damage. Your veterinarian will monitor your dog closely and may prescribe medications like prednisone or antihistamines to reduce inflammation and allergic reactions. Be vigilant for signs of complications, such as coughing, vomiting, or lethargy, and contact your vet immediately if these occur.

6. Prevent Reinfection
After treatment, it is crucial to start your dog on a monthly heartworm preventive medication to avoid reinfection. These medications are highly effective and come in various forms, such as chewable tablets, topical solutions, or injections. Your veterinarian will recommend the best option for your dog.

7. Long-Term Care and Monitoring
Even after successful treatment, your dog may require ongoing care to manage any lasting damage to the heart and lungs. Regular check-ups, including blood tests and imaging, will help monitor your dog's recovery. Your vet may also recommend a heart-healthy diet and supplements to support cardiovascular health.

8. When to Seek Professional Help
If your dog shows severe symptoms, such as collapse, pale gums, or extreme difficulty breathing, seek emergency veterinary care immediately. These could indicate a life-threatening complication, such as caval syndrome, which requires surgical intervention.

9. Prevention Tips
Preventing heartworm disease is far easier and safer than treating it. Ensure your dog is on a year-round heartworm preventive medication, even in colder months when mosquitoes are less active. Regular testing is also essential, as early detection can make treatment more manageable.

10. Additional Considerations
Heartworm treatment can be expensive and emotionally taxing, so it is important to discuss the financial and emotional aspects with your veterinarian. Some clinics offer payment plans or financial assistance programs to help manage costs. Additionally, consider the emotional toll on your dog and yourself, and seek support if needed.

In summary, a positive heartworm test requires prompt and careful action. Work closely with your veterinarian to develop a treatment plan, manage risks, and ensure your dog's long-term health. Prevention remains the best strategy, so prioritize regular testing and preventive medications to protect your dog from this dangerous disease.