Metaldehyde (Slug and Snail Bait) Poisoning – Metaldehyde poisoning is a severe and sometimes fatal toxicity caused by taking products containing metaldehyde, a chemical used in slug and snail baits. While pest control with these products is very effective, the danger to pets, wildlife, and occasionally children from accidental ingestion is serious.
What is Metaldehyde?
Metaldehyde is a crystalline compound typically in the form of some type of pellet, granule, or liquid in slug and snail repellents. Metaldehyde is extremely toxic to mammals and works by disrupting the central nervous system. The fact that metaldehyde is appetizing to pets, especially dogs, is a significant risk, as it is often mixed with food-based bait like bran or molasses mixed with an appetizing substance to attract the slug/snail.
Metaldehyde has been used since the 1940s and is still frequently used in the agricultural and gardening world, but since many products are toxic, it has recently come under the spotlight with regulations in many countries.
How Does Metaldehyde Poisoning Occur
Approximately 80% of cases of metaldehyde poisoning result from oral ingestion. This may be from bait products or from swallowing a slug/snail that has metaldehyde in its system or on it. Dogs are more often than not the culprit, inhaling, ingesting, and that is where the problem starts. Cats will not ingest bait as much as dogs, but there have been cases. Here are some other potential sources of exposure, including –
- Treated bait is spilled in gardens or garages
- Slug pellets are stored incorrectly.
Contamination occurs when some residue on your hands is transferred to pet food or human snacks.
Symptoms Associated with Metaldehyde Poisoning
Typically, symptoms will occur from 30 minutes to 3 hours post-exposure and can progress quickly. Early intervention is important with this type of poisoning for survival. Some of the clinical signs to watch for include –
Neurological Symptoms
- Muscle tremors
- Seizures
- Hyperactivity/agitation
- Incoordination (ataxia)
Gastrointestinal Symptoms
- Vomiting
- Diarrhea
- Excessive salivation
- Decreased appetite
Systemic Symptoms
- Elevated body temperature (hyperthermia)
- Increased heart rate (tachycardia)
- Uncontrolled respiratory distress
- Coma (in severe cases)
The severity of symptoms depends on the amount of metaldehyde ingested and the speed with which treatment is started. One note about animals, especially dogs, you will see the severity suddenly escalate from any of the associated symptoms above.
Diagnosis of Metaldehyde Poisoning
Veterinarians often make the diagnosis of metaldehyde poisoning based on clinical signs alone and a history of potential exposure. If ingestion is suspected, bringing in the bait packet or a sample of vomit can help confirm the diagnosis. There are no specific blood tests available for metaldehyde, but the laboratory work may present as –
- Metabolic acidosis
- Abnormal liver enzymes
- Dehydration/electrolyte derangement
Treatment Considerations
Your prompt veterinary referral is important in the event of metaldehyde poisoning. There is no antidote for metaldehyde, which means that treatment involves providing supportive and symptomatic care. The following will be considered as part of your treatment plan –
- Inducing vomiting (if ingestion was recent and not contraindicated)
- Activated charcoal to reduce repeated absorption
- IV fluids for hydration and organ support
- Muscle relaxants (example: diazepam or methocarbamol) to decrease tremors and seizures
- Cooling methods for pets that become hyperthermic
- Seizure medications are used when the animal continues to seize.
Hospitalization for critical care is typically required for 24 – 72 hours based on the level of toxicity.
Prognosis
The prognosis of metaldehyde toxicity largely depends on –
- Amount ingested
- Time to treatment
- Overall health of the animal (underlying illness)
Pets treated quickly and aggressively have a reasonable chance of survival, although death in untreated or delayed cases is often due to respiratory failure, hyperthermia, or multi-organ failure.
Prevention Plan
For Pet Owners –
- Store snail/slug bait in a locked cabinet / on locked shelves out of reach
- Do not use metaldehyde-based products; use ones made with iron phosphate instead (pet safe)
- Dogs and cats should be supervised when in the area of any treated area
- Any spilled pellets should be cleaned immediately
For Gardeners –
- Use other non-poisonous forms of pest control (copper tape, beer traps, nematodes)
- Educate neighbors and communities about the potential dangers associated with chemicals used to treat gardens/yards of pets and children.
- Install physical barriers to keep animals out of treated areas.
For Parents –
- Teach children about the potential dangers of using chemical products in the garden or yard.
- Keep products in their containers with child-proof caps
- Never transfer metaldehyde from its original container to food storage containers or unknown, unlabeled jars
Environmental Considerations
Metaldehyde can be a potential environmental hazard, particularly to aquatic environments. If metaldehyde is released into the environment, it can make its way into rivers and streams through rainwater runoff and potentially affect aquatic organisms. As a result of these types of environmental concerns, some regulatory agencies in the EU and UK have recalled or restricted specific metaldehyde formulations.
Conclusion
Metaldehyde poisoning can be serious for pets, wildlife, and children, and is completely preventable. Knowing the signs and symptoms, acting quickly, and using safer pest control methods are important things we can all do to protect those that we love. When gardeners and homeowners are using chemical pest control methods, they should always assess the potential risks and benefits.
However, if we always use non-toxic alternatives and limit the exposure of our friends and family to pests and chemicals, we can have a healthy garden and lifestyle for our companions and not put them or the environment at risk.
FAQs
Is Metaldehyde poisoning fatal to pets?
Yes, if veterinary care is not received in time, metaldehyde poisoning can be fatal. However, many pets make a complete recovery with prompt medical attention and supportive care. The time of exposure to ingestion is a critical determinant of the outcome.
How much metaldehyde is dangerous for dogs or cats?
While there are no specific values, the amount ingested can generally be toxic to smaller animals. Even dogs, with doses > 0.5 grams/kilogram of usage, can produce metaldehyde poisoning. Since pet-safe limits depend on individual pet health factors, and since every pet’s health and sensitivity vary, any suspicion that your pet consumed metaldehyde means you should seek emergency care.
Are there safer choices instead of Metaldehyde?
Yes. Iron phosphate-based slug bait is efficacious and safer for pets, children, and wildlife. Other options include copper barriers, diatomaceous earth, and organic methods of gardening.
What should I do if my pet has eaten slug bait?
- Act quickly
- Remove any bait that remains in the pet’s mouth.
- Don’t try to use any home remedy.s
- Call your veterinarian or the animal poison control center
- Take the pet to the emergency vet clinic immediately.
