Heartworm Prevention: Protecting Your Pet Year-Round
Heartworm disease is fatal but entirely preventable. Understand the importance of consistent prevention for dogs and cats.
Heartworm disease is one of the most serious but preventable diseases in pets. Transmitted by mosquitoes, heartworms live in the heart and lungs, causing heart failure, lung damage, and death. Prevention is simple, safe, and far less expensive than treatment. RVC provides heartworm testing and prevention products. Call +853 6677 6611.
Key Points
- Heartworm disease is transmitted by mosquitoes and is fatal if untreated
- All dogs should be on year-round heartworm prevention
- Cats are also at risk, though they are not the natural host
- Monthly oral or topical preventatives are highly effective
- Annual heartworm testing is recommended even for pets on prevention
- Treatment for heartworm disease is dangerous, expensive, and takes months
How Heartworm Disease Works
When a mosquito bites an infected animal, it picks up microscopic heartworm larvae. When that mosquito bites your pet, the larvae enter the bloodstream. Over 6 months, they mature into adult worms (up to 12 inches long) that live in the heart, lungs, and associated blood vessels. Adult worms produce offspring (microfilariae) that circulate in the blood, continuing the cycle when another mosquito bites.
Prevention Products
Monthly preventatives (ivermectin, milbemycin, moxidectin, selamectin) kill larvae before they mature. Options include: chewable tablets (Heartgard, Interceptor), topical solutions (Revolution, Advantage Multi), and injections (ProHeart 6 or 12 — provides 6 or 12 months of protection). All are highly effective when given on schedule. Some products also protect against fleas, ticks, and intestinal parasites.
Testing Requirements
Dogs should be tested for heartworm annually before starting or continuing prevention. Testing detects adult heartworms — if your dog has adult worms and you give prevention, it can cause a dangerous reaction. In Macau, heartworm is endemic year-round due to the warm climate. Cats are harder to test — diagnosis often requires X-rays, echocardiogram, or antibody tests.
Treatment vs Prevention Cost
Prevention costs approximately $50-150 per year depending on product. Treatment for heartworm disease costs $500-1500+ and involves: strict cage rest for months, multiple injections of an arsenic-based drug (melarsomine), pain management, and monitoring for complications. Some dogs don't survive treatment. Prevention is clearly the better choice — it's safer, cheaper, and keeps your pet healthy.
When to See a Vet Immediately
- Dog is not on heartworm prevention
- Coughing, exercise intolerance, or weight loss in a dog at risk for heartworm
- Annual wellness visit for heartworm testing
- Moving to or traveling to a heartworm-endemic area
- Missed doses of heartworm prevention
- Any concern about heartworm risk
How RVC Can Help
RVC provides heartworm testing and carries a full range of prevention products. Protect your pet year-round — call +853 6677 6611.
This article is for educational purposes only and does not replace professional veterinary advice. If your pet is showing any symptoms, please contact Royal Veterinary Center immediately at +853 6677 6611.