Metaldehyde (Slug and Snail Bait) Poisoning

What is metaldehyde?

Metaldehyde is a chemical commonly found in slug and snail baits. Rarely, metaldehyde can also be found in solid fuels used for camp stoves. Slug and snail baits come in granular, liquid, spray, dust, pellet, meal, gel, and paste forms. Baits are designed to be placed around walkways and gardens. To attract slugs, they often contain bran or molasses, making them tasty to other animals.

What is metaldehyde poisoning?

Poisoning occurs when pets eat metaldehyde-containing slug or snail bait off the ground or from the storage container. Dogs, cats, birds, and other wildlife can all be affected by metaldehyde. Metaldehyde may cause signs of poisoning even when the animal ingests very small amounts.

What are the signs of metaldehyde poisoning?

The signs of metaldehyde poisoning are called “shake and bake,” because animals may have severe tremors or seizures (shake) and an alarmingly elevated body temperature (bake). Signs of poisoning are generally seen within a few minutes, and up to three hours after ingestion.

Early signs may include drooling, vomiting, panting, and anxiety, which can progress to include depression, a wobbly gait, or the characteristic muscle tremors, seizures, and hyperthermia. The high body temperature may cause damage to internal organs. Severe cases can result in the animal becoming comatose. 

If you suspect your pet has ingested metaldehyde, immediately call your veterinarian or Pet Poison Helpline, a 24/7 animal poison center, at 1-800-213-6680. There is no time to delay, as death can occur very quickly. If left untreated, or if the pet has a poor response to treatment, respiratory failure and death can occur. Sadly, some pets that survive these initial signs develop liver failure two to three days after ingestion.

How is metaldehyde poisoning diagnosed?

Diagnosis is based on development of the expected signs and a known or suspected history of exposure to slug or snail bait. Metaldehyde levels in the blood, urine, stomach contents, or liver can be measured at a specialized laboratory.

Blood work may be performed to rule out other possible causes of the pet’s signs and to monitor for complications that require further treatment. Abdominal radiographs (X-rays) sometimes show bait in the stomach or intestines.

How is metaldehyde poisoning treated?

If a pet has ingested metaldehyde, diagnostics and treatments include decontamination, bloodwork monitoring, intravenous fluid therapy, liver support, and medications to control clinical signs. There is no antidote for metaldehyde, but supportive care can treat clinical signs and help prevent more serious complications. Treatment may be required for several days.

What is the prognosis for metaldehyde poisoning?

The outcome for metaldehyde poisoning depends on many factors, including the initial health of the pet, amount ingested, and time to treatment. With early treatment, pets are less likely to develop serious signs. Even when signs occur, many pets recover fully within two to three days if appropriate treatment is started early.

How can metaldehyde toxicity be prevented?

Avoid using slug and snail baits that contain metaldehyde in any area that can be accessed by non-target animals. Not only can these baits harm your pets, they can also harm wildlife. Many gardeners use broken shells, lava rock, or other rough materials to deter slugs from the area without using chemicals. Placing copper bands around plants or planting lavender, mint or rosemary may also discourage slugs and snails from entering the garden.

Slug and snail bait products that contain iron phosphate instead of metaldehyde are considered safer for pets. These baits are still potentially toxic due to the iron content, but much larger doses are required to cause poisoning.

If you use metaldehyde, always store the product out of reach of children and pets. Metaldehyde should be stored in closed containers to prevent accidental ingestion by pets. Pets should not have access to areas where metaldehyde has been applied, as some products may remain active in soil for several weeks. Always follow labeled instructions for application.

If your pet consumes metaldehyde, immediately contact a veterinarian or Pet Poison Helpline, at 1-800-213-6680. Prompt treatment provides the best chance for a full recovery.

Pet Poison Helpline, an animal poison center based out of Minneapolis, MN, is available 24/7 for pet owners and veterinary professionals that require assistance treating a potentially poisoned pet. The staff provides treatment advice for poisoning cases of all species, including dogs, cats, birds, small mammals, large animals and exotic species. As the most cost-effective option for animal poison control care, Pet Poison Helpline’s per-incident fee includes follow-up consultations for the duration of the poison case. Pet Poison Helpline is available in North America by calling 800-213-6680. Additional information can be found online at www.petpoisonhelpline.com.