Heartworm Prevention Guide
This page is educational reference material for preparing questions. A licensed veterinarian examines the animal, makes the diagnosis, and sets the treatment.
Heartworm disease prevention for dogs and cats. Monthly preventatives compared, testing schedules, and treatment if infected.
Key Information
What You Need to Know
Practical Recommendations
Expert Tips
- Avoid feeding immediately before or after intense exercise to reduce bloat risk in pets prone to gastric issues.
Understanding the Research
Budgeting for Pet Care
Related Guides
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Key Questions
Think of this as the knowledge layer that most pet owners skip and later wish they had started with. Because each pet is its own animal, treat any general guideline as a starting point and refine from there.
Where can I learn more?
The American Heartworm Society guidelines are the reference for the antigen test before a dog starts prevention and for yearly testing after that. They also cover why cats are harder to test and still use prevention. The American Heartworm Society guidelines cover year-round prevention. If you miss a dose, call the clinic before you give the next one; do not double it.
How often should I take my pet to the vet?
The American Heartworm Society expects a heartworm antigen test before a dog starts prevention and then once a year. That test sits on the exam schedule: puppies every 3 to 4 weeks until about 16 weeks, adult dogs at least annually. Many dogs from about 7 years, giant breeds earlier, are examined about every six months for other problems, while the antigen test itself stays yearly unless doses were missed. Cats are harder to test and still use prevention; kittens are seen every 3 to 4 weeks until about 16 weeks, adult cats about yearly, and many cats from about 10 every six months. Coughing or collapse in a dog who skipped pills should be seen immediately.
How can I save money on pet care?
A year of prevention plus the annual heartworm antigen test the American Heartworm Society expects is the planned spending. Treatment of a heartworm infection is a series of injections and strict rest, a much larger event than that year of prevention. Do not skip a dose to stretch a box, and do not split one dog's product with another animal. If you miss a dose, call the clinic before you restart, and do not double the next pill.