Slug and Snail Bait Poisoning in Dogs

Many commercial preparations for eliminating slugs and snails contains a chemical known as metaldehyde. These pellets, designed to attract destructive mollusks like slugs and snails, then poison them, are also attractive and lethal to many other birds and mammals, both wild and domestic. Metaldehyde is a potent neurotoxin and can be lethal at just one teaspoon per ten pounds of weight. If your dog has sampled any of these capsules, or if you suspect that they have eaten any, contact your veterinarian right away or take your pet directly to their doctor or to the nearest emergency veterinary hospital.

Slug and snail bait is usually made using the chemical metaldehyde, a powerful neurotoxin. Ingestion of this chemical can be lethal in just a few hours and should be considered an emergency.

Symptoms of metaldehyde poisoning from eating slug and snail bait are usually apparent within 1- 4 hours after eating the substance. These symptoms can include:

• Anxiety
• Collapse
• Convulsions
• Diarrhea
• Difficulty breathing
• Disorientation
• Drooling
• Death
• Excessive excitement
• Extreme sensitivity to sound and touch
• Fever
• Heavy panting
• Lack of coordination
• Rapid breathing
• Rapid heart rate
• Respiratory failure
• Seizures
• Tremors
• Twitching
• Unsteady gait
• Vomiting

Types

There are alternatives to the metaldehyde-based slug and snail baits, with varying toxicity potentials. Some of these include: 

Iron phosphate is a mineral that is found naturally in small amounts in the soil, however, the bait also has specific additives that cause the slug or snail that feeds on it to stop feeding altogether, seek hiding places, and become inactive. Iron phosphate itself is considered non-toxic, but the additives such as EDTA may not be as harmless.

Coffee is sometimes used as bait. 1%-2% caffeine solutions will kill most of the slugs and snails on plants, and even the concentrations found in coffee, around .05%, will repel many.

Diatomaceous Earth appears powdery but is made up of the hard, jagged remains of fossilized algae. It lacerates soft-bodied organisms like snails and slugs, causing them to dehydrate.

Metaldehyde poisoning in dogs is mostly caused by eating slug and snail bait pellets, however, skin and eye irritation can occur from contact, and it is also toxic when inhaled. Metaldehyde is a neurotoxin that affects not only our pets but can be a fatal attraction for wildlife as well. Many varieties of pellet are formulated with ingredients that make them attractive to slugs and snails, like apples and molasses. This makes them an attractant for all sorts of animals, and metaldehyde is toxic for most birds and mammals. In some cases, a predatory animal, such as your dog, may be poisoned by eating another animal that had consumed the slug bait earlier.

Identification of the pellets is usually enough information to suggest a preliminary determination if the consumption of the molluscicide was witnessed. If your dog ate a substance that you think may be a slug and snail bait pellet and is exhibiting symptoms, but you are not sure of the chemical, it may be wise take a sample of it with you to the veterinary clinic, to ensure a speedier identification for treatment. If the ingestion of the product was unobserved, you would be asked questions about any opportunistic eating that is suspected as well as any prescriptions or supplements that your dog is taking. 

The symptoms generally indicate the involvement of a neurotoxin and standard blood chemistry tests, such as a biochemistry profile and a complete blood count (CBC), will be done in an attempt to confirm or reveal which toxins are responsible for the reaction and to check for any drug interactions that may affect the treatment plan. Pieces of the pellets are often found in the vomit and stools of dogs that have eaten any of these pesticides.

If you have caught your pet consuming any amount of slug and snail bait, he should be taken to the veterinarian’s office for decontamination and supportive therapies as soon as possible. Vomiting will be induced if the bait was eaten in the last few hours, and activated charcoal will be administered to the canine in an attempt to soak up as much of the metaldehyde as possible. Gastric irrigation is typically done under general anesthesia and will be used to remove as much of the toxic compound from the patient’s stomach as possible and to prevent the toxin from spreading from the digestive system into the bloodstream. 

There is no antidote to poisoning from metaldehyde as is found in the majority of slug and snail bait formulations, so treatment is generally supportive beyond decontamination, including IV fluids for dehydration as well as mixtures of sugars and electrolytes to make adjustments for any imbalances that develop. Anti-seizure medications may also be dispensed to reduce or halt the seizures and tremors characteristic of metaldehyde poisonings. If the tremors or convulsions continue after traditional anti-seizure medications are administered, your veterinarian may choose to anesthetize your pet until the toxin has been cleared from their system.

Symptoms of neurotoxicity from ingesting slug and snail bait can last several hours and pets that are recovering from anesthesia, as is required for gastric irrigation, may have coordination difficulties when they return home. They are often disoriented and confused, and isolation from other pets and from children may be advised until both the sedatives and the toxic compounds have fully cleared your companion’s system. Extra bathroom breaks should be planned while your dog is recuperating, and a calm and quiet environment will help improve recovery times. In some circumstances, your veterinarian may also recommend regular monitoring of blood chemistry levels for your canine, particularly regarding the functionality or impairment of the liver and kidney.