Metaldehyde, commonly found in snail and slug bait, can be toxic to both cats and dogs if ingested. Clinical signs of toxicity can appear just minutes after ingestion and death from respiratory failure can occur within a few hours.
Signs and symptoms of toxicity: Signs of toxicity include anxiety, increased heart rate, panting, increased production of saliva, vomiting, diarrhea, depression, continuous seizures, dilated pupils, abnormal increase in breathing, and difficulty walking.
Toxic consumption: There is no established threshold for toxicity. All incidents of exposure should be reported immediately.
Dolder, L. (2003). Metaldehyde toxicosis. Veterinary Medicine (March):213-5.