Mole and Gopher Bait Poisoning

What are mole and gopher baits?

Moles and gophers tunnel underground and can cause significant damage to gardens and lawns. Mole and gopher baits are poisonous products intended to attract and kill these pests. The poisonous baits are designed to be used underground and are often flavored to attract unwanted pests. They come as pellets, granules, stakes, and “worms” (baits in the shape of earthworms to mimic their natural food source). Mole and gopher baits can be found in farm supply stores, garden centers, residential hardware stores, or online.

How does mole and gopher bait poisoning occur?

Because mole and gopher baits are often flavored to attract pests, cats and dogs can be attracted to them and may ingest them if given the chance. Although these baits are intended to be placed underground, dogs and cats may dig up the bait or find the bait packaging in a garage or shed.

The active ingredients in these baits can cause significant illness in your pet if they ingest enough. The most common active ingredients used in mole and gopher baits are zinc phosphide and bromethalin.

• When zinc phosphide enters the moist environment of the gastrointestinal tract, phosphine gas is generated. This gas is poisonous and can be fatal.
• If a toxic dose of bromethalin is ingested, it can cause brain swelling and subsequent neurological signs. Bromethalin is also found in mice and rat baits, but the concentration is much higher in mole and gopher baits.

What are the clinical signs of mole and gopher bait poisoning?

Clinical signs of zinc phosphide poisoning usually appear quickly, although they may sometimes be delayed up to 24 hours. Signs in your pet may include:

• Vomiting
• Diarrhea
• Bloating
• Lethargy
• Depression
• Tremors
• Agitation
• Seizures

Clinical signs of bromethalin poisoning can develop any time within seven days of ingestion. Signs depend on the dose ingested, and may include:

• Vomiting
• Weakness
• Paralysis
• Walking off-balance
• Tremors
• Seizures

How is mole and gopher bait poisoning diagnosed?

Mole and gopher bait poisoning is often diagnosed from a witnessed exposure, or evidence of a suspected exposure, such as spilled or chewed packaging. Diagnosis can also be based on clinical signs or a notable foul odor. If you suspect your pet ingested mole and gopher bait, immediately contact your veterinarian or Pet Poison Helpline, a 24/7 animal poison center, at 1-800-213-6680.

How is mole and gopher bait poisoning treated?

Treatment for your pet may include decontamination, bloodwork monitoring, fluids, gastrointestinal support, and medication to control tremors and seizures. Never attempt to induce vomiting without the guidance of your veterinarian or a toxicology expert at Pet Poison Helpline. Particular caution should be used if vomiting is induced, as this bait may generate phosphine gas in the gastrointestinal tract, which is toxic to humans.

There is no antidote for bromethalin or zinc phosphide poisoning, so decontamination within an appropriate time is key to a good outcome. If clinical signs develop, they can be managed with medication.

What is the prognosis for mole and gopher bait poisoning?

The prognosis for mole and gopher bait poisoning is largely dependent on the active ingredients, time of decontamination, and severity of the pet’s condition. With bromethalin poisoning, there is a more guarded (uncertain) prognosis, dependent on controlling brain swelling. If the exposure or clinical signs are not treated quickly, prognosis may be poor.

How can I prevent mole and gopher bait poisoning?

Be careful to keep all bait packaging securely stored and out of reach of children and pets. If bait is placed around your home, consider whether your pet will be able to gain access to the area. Be sure to read the entire product label before use, to identify warnings and instructions for safe and proper handling and placement. Keep the packaging or make a note of the active ingredient in your product.

If you think your pet may have been poisoned, seek veterinary care immediately or call Pet Poison Helpline, a 24/7 animal poison center, at 1-800-213-6680 for advice. Timely treatment could save your pet’s life.

Pet Poison Helpline, an animal poison control 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.