Updated September 25, 2026. Fact-checked against veterinary sources; review by a licensed veterinarian is in progress. See our editorial policy.
Quick answer: No natural remedy has been proven to reliably treat or prevent intestinal worms, heartworm, fleas, or ticks in dogs. Popular options like garlic, diatomaceous earth, pumpkin seeds, apple cider vinegar, and essential oils either don’t work well enough or can be harmful. Missing effective prevention can lead to serious disease, especially heartworm. Veterinary parasite preventives are well studied, safe for most dogs, and far more reliable.
Common remedies and the evidence
- Garlic: doesn’t reliably repel fleas and can damage red blood cells in dogs
- Diatomaceous earth: not proven to treat worms, and can irritate lungs if inhaled
- Pumpkin seeds: no reliable evidence against dog worms
- Apple cider vinegar: no evidence against fleas or worms
- Essential oil sprays and collars: inconsistent protection, and some oils (like tea tree and pennyroyal) are toxic, especially around cats
- “Natural” heartworm prevention: none proven. Heartworm disease is serious and costly to treat
What works
- Year-round heartworm prevention, most of which also treats common intestinal worms
- Veterinary flea and tick preventives
- Regular fecal tests
- Picking up dog waste promptly
- Tick checks after outdoor time
Why it matters for people too
Some dog parasites, like roundworms and hookworms, can infect people, especially children.
Sources
- Companion Animal Parasite Council (CAPC): General guidelines for dogs
- American Heartworm Society: Canine heartworm guidelines
- Merck Veterinary Manual: Gastrointestinal parasites of small animals
- Pet Poison Helpline: Essential oils
This article is for general education and is not a substitute for care from your own veterinarian. Learn about The Pet Vet and our editorial policy.