Are Snails Poisonous to Dogs?

The toxic compounds in snails:

• Lungworm larvae carried by snails/slugs (Crenosoma vulpis / fox lungworm, and Angiostrongylus vasorum / French heartworm where present) — snails are intermediate hosts; dogs become infected by eating snails or even ingesting their slime trail
• Metaldehyde — the active ingredient in most slug and snail baits commonly found near snails; highly toxic to dogs in very small amounts ('shake and bake' poisoning)
• General gastrointestinal upset and bacterial/parasite contamination from eating wild snails

If your dog ate snails, watch for:

• •Lungworm (Crenosoma vulpis / Angiostrongylus vasorum): coughing, wheezing, increased breathing rate, respiratory distress, exercise intolerance; severe Angiostrongylus cases cause bleeding/clotting disorders, anemia, and can be fatal
• •Metaldehyde slug-bait poisoning: drooling, vomiting, panting, anxiety, wobbly gait (ataxia), severe muscle tremors, seizures, dangerously high body temperature; untreated cases progress to respiratory failure and death, with possible liver failure 2-3 days later
• •Vomiting, diarrhea and general GI upset from ingesting wild snails

My dog ate a snail in the garden — should I worry?

Yes, take it seriously. Snails are intermediate hosts for lungworm parasites (such as Crenosoma vulpis and, in some regions, the potentially fatal Angiostrongylus vasorum). A single snail can transmit infective larvae, and dogs can even pick up lungworm from snail slime trails. Contact your vet — lungworm symptoms (coughing, breathing trouble) can take weeks to appear, and many vets recommend a preventive deworming plan.

Are snails themselves poisonous, or is it the slug bait that's the danger?

Both are real risks. Wild snails biologically carry lungworm larvae and can cause GI upset. Separately, most commercial snail and slug baits contain metaldehyde, which is highly toxic to dogs in tiny amounts — the baits are sweetened to attract slugs, which also tempts dogs. If there is any chance your dog ate snail bait, this is an emergency: call your vet or Pet Poison Helpline (855-764-7661) / ASPCA (888-426-4435) immediately.

How do I keep my dog safe from snails and lungworm?

Discourage your dog from eating or playing with snails and slugs, remove snails from areas your dog uses, pick up and rinse outdoor water bowls and toys that snails may have crawled over, never use metaldehyde slug bait where pets have access (choose pet-safe iron-phosphate alternatives), and ask your vet about a routine parasite/lungworm preventive — especially in regions where Angiostrongylus vasorum is established.

• VCA Animal Hospitals — Lungworm Infections in Dogs
• VCA Animal Hospitals — Metaldehyde Toxicity (Slug Bait Poisoning)

Last updated 2026-06-25