With Spring upon us, we’re fighting the snails off our veggie gardens. There are a number of slug and snail baits on the market, often in a pellet form made with ingredients that are attractive to dogs and every year we see very unwell dogs who have eaten the “pet safe” brands of bait.
The most dangerous ingredient in some of these baits is Metaldehyde. Many formulations of pellets, liquid, powder, granule and gel contain this toxin as it is very effective in killing snails and slugs. Unfortunately it can also kill dogs and cats. Metaldehyde effects multiple organ systems but most dramatically the central nervous system. It acts in the brain to reduce the concentrations of “GABA”, an inhibitory neurotransmitter, resulting in brain hyperactivity. The effects can occur within 30 minutes or up to 24 hours after ingestion. We typically see vomiting, hyper-salivation, anxiety, restlessness, rapid heart-rate and panting, hypersensitivity to sound and touch, and flickering eyes. Eventually it progresses to muscle rigidity, seizures, and comas. Pets can and do die from toxicity, often from respiratory failure, multi-organ failure, and blood clotting abnormalities. Animals who survive have become blind for up to 3 weeks.
If your pet has eaten a bait containing metaldehyde it is an emergency. There is no antidote, but if treated early, we can induce vomiting and stop your pet absorbing a lethal dose. If your pet is already showing signs, we can give supportive therapy to minimise the effect and risk of death. Patients who survive the first 24 hours generally recover fully, although temporary blindness and delayed liver damage are rare possibilities.
Other leading brands of snail and slug killers contain Methiocarb. Methiocarb is highly toxic if ingested by your dog with less than a teaspoon causing signs of poisoning. Then poison causes an overstimulation of the nervous system and the signs are panting or rapid respiration, excessive drooling, continuous muscle twitching, lack of coordination, anxiety, very rapid heart rate, vomiting and diarrhoea, very high temperature and seizures.
Death will occur within 2-4 hours of ingestion if left untreated. Once again, no specific antidote exists for Methiocarb poisoning but we do have a partial antidote that reverses some of the symptoms and makes the dog a little more comfortable. Approximately 10% of dogs that are poisoned with Methiocarb will go on to suffer from intussusception of the intestine requiring an emergency surgery and removal of the affected bowel.
Some baits are labelled as “pet safe”. These generally contain Iron EDTA or Iron Phosphate, which is a safer alternative to Metaldehyde, but still something to keep pets away from. The iron products are not technically a poison, but if animals eat enough, which is often only a teaspoon to a few tablespoons, they are toxic and potentially lethal. Iron toxicity from these baits initially causes an acute corrosion of the lining of the bowel causing severe abdominal pain, vomiting and diarrhoea and then damaging the liver which can be irreversible and fatal. If your pet has eaten an Iron based bait, it should still be treated as an emergency.