Verdict: No, dangerous
Snails are dangerous for dogs to eat due to the risk of transmitting various parasites, most notably the rat lungworm (Angiostrongylus cantonensis). These parasites can cause severe and potentially fatal neurological disease or other organ damage. If your dog has eaten a snail and shows any signs of illness, seek immediate veterinary attention.
Ingestion of snails infected with parasites can lead to parasitic migration within the dog's body, causing inflammation, neurological damage, or other organ system dysfunction depending on the specific parasite.
Angiostrongylus cantonensis (rat lungworm), other parasites (e.g., flukes, tapeworms)