Elmer and Harvey’s Bout with Bromethalin

One morning in February 2026, John woke to find that his two dogs, Elmer and Harvey, had gotten into a package of bromethalin rodenticide sometime during the night. Two pounds of bait was missing.

What is Bromethalin?

Bromethalin is a neurotoxin commonly found in rat, mouse and mole killers. It comes in several different forms including blocks, pellets and worm- and grub-shaped baits. Ingestion of enough bromethalin can lead to fluid accumulation in tissues of the nervous system resulting in weakness, tremors, seizures, paralysis and potentially death. At lower doses, bromethalin could cause less severe symptoms like ataxia, hind-limb weakness and lethargy that may eventually resolve over weeks to months.

How ASPCA Poison Control Helps

Once John realized what had happened, he contacted his primary care veterinarian and was instructed to induce vomiting in Elmer and Harvey (this should only be done under the direction of a veterinary professional). Both dogs produced a large amount of bait in their vomit. Now knowing that both dogs were involved in this mishap, John also gave ASPCA Poison Control a call.

ASPCA Poison Control Veterinary Technician Ian spoke with John regarding the type and amount of rodenticide that Elmer and Harvey ingested. It was determined that both dogs could have easily ingested enough rodenticide to cause severe, and potentially fatal, symptoms. John was instructed to seek emergency veterinary care for both dogs. ASPCA Poison Control veterinarians were also going to work with his local emergency veterinarian to ensure Elmer and Harvey received the lifesaving care they needed.

Upon presentation to the Emergency Veterinary Care Center, the veterinary staff contacted ASPCA Poison Control and spoke with ASPCA Poison Control Veterinarian, Dr. Bachleda, for guidance on Elmer and Harvey’s treatment. At high enough doses, bromethalin can cause severe irreversible damage to the nervous system and there is no antidote. Once clinical signs begin, the prognosis is grave if signs are severe. Because of this, prompt decontamination to prevent clinical signs is imperative.

Activated charcoal is currently the only well-established intervention to effectively delay the onset of clinical signs and reduce the severity of toxicity in dogs. Bromethalin and its toxic metabolites are recycled between the liver and intestines, so repeated doses of activated charcoal effectively traps the toxin in the GI tract where it can be eliminated from the body without being absorbed into the bloodstream.

Activated charcoal should only be given by trained veterinary professionals as it can easily be inhaled into the lungs, resulting in severe pneumonia if administered forcibly or if the pet were to vomit shortly after administration. Repeated doses of activated charcoal also come with risk of severe electrolyte disturbances due to dehydration, which can also be fatal if not managed professionally.

One Hospital Stay Later

After their bromethalin ingestion, Elmer and Harvey spent 48 hours in the emergency veterinary hospital under very close supervision while they received multiple doses of activated charcoal, IV fluids and electrolyte monitoring. Thankfully, neither dog developed any signs of toxicosis and returned home happy and healthy.

Every year, ASPCA Animal Poison Control fields thousands of calls and works on cases just like Elmer and Harvey’s, helping pet parents get immediate, expert care when their pets get into something potentially toxic.

If you think your pet could have ingested something toxic, contact ASPCA Poison Control at (888) 426-4435 or your local veterinarian immediately.