Owners beware: Poisoning from this rodenticide is tough to treat

Pet owners using rodenticides should be aware that cats and dogs are susceptible to the products’ poison, and veterinarians fear an increase in bromethalin toxicity in pets because of a ban on brodifacoum. Bromethalin is the active ingredient in Assault, Fastrac, Gladiator, Rampage, Talpirid and Vengeance, and it causes brain and spinal cord swelling characterized by weakness, incoordination, seizures, paralysis and death. There is no definitive diagnostic test and no antidote, note veterinarians Lee Pickett and Jennifer Coates. Supportive treatments are available but they are intensive, and animals that survive are often left with neurological deficits. PetMD.com/Fully Vetted blog (3/12), BerksPets.com (Reading, Pa.) (3/11)

The EPA provides a list of rodenticides that meet their safety standards and are approved for homeowner use on their website. Two, diaphacinone and chlorophacinone, are short-acting anti-coagulants similar to warfarin, which we touched upon yesterday. Any pet poisonings that are caused by these products should be comparatively simple to diagnose and treat, as long as pets are seen by a veterinarian in a timely manner.
The third active ingredient on the EPA list, bromethalin, is more concerning. Bromethalin is a neurotoxin. It causes fluid to build up within the brain. The swelling puts pressure on nerves, which inhibits their ability to transmit impulses. The symptoms that develop depend on the dose of the poison that an animal ingests. At relatively low exposures, symptoms include unsteadiness, weakness that starts in the hind end and can progress forward, muscle tremors, depression, and vomiting. When a dog gets into a large amount of bromethalin, the symptoms are more severe. Pets typically develop some combination of the following:


  • muscle tremors
  • seizures
  • hyperexcitability
  • unsteadiness
  • paddling of the limbs
  • high body temperature
  • a loss of voice
  • stiffness in the front legs


Testing for bromethalin exposure is not readily available so diagnosis is dependent on a history of exposure (if that is known) and a pet’s clinical signs.
With hindsight, I think I may have treated one dog for bromethalin poisoning, though I didn’t know it at the time. This dog belonged to an owner who was in town for a horse show. My patient was brought into the clinic with a weird panoply of symptoms, some of which fit with those mentioned above. We suspected that he had gotten into something at the horse show, but could never determine exactly what that might have been. My guess is that someone may have put out a bromethalin-containing rodenticide around the barns.
Decontamination (e.g., inducing vomiting and giving activated charcoal) is very helpful within a few hours of ingestion, but once symptoms develop treatment for bromethalin poisoning revolves around trying to decrease swelling within the brain, dealing with symptoms as they arise, and patient support. Since I didn’t have a definitive diagnosis for my patient, I was limited to symptomatic and supportive therapies. It was touch and go for awhile, but he was much improved after a few days of hospitalization, and a follow-up phone call to his home in California revealed that he had made a complete recovery.
He was lucky, if he had eaten more of the poison or had been brought in even a day later, I probably wouldn’t have been able to save him.
I hope bromethalin poisonings do not increase as a result of the ban on brodifacoum. Sending pets home with vitamin K after exposure to brodifacoum is far less stressful than hospitalizing them for severe neurologic dysfunction without a way to reach definitive diagnosis and no antidote in sight.

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22 Responses to “Owners beware: Poisoning from this rodenticide is tough to treat”

  1. avery says:

    My dog just ingested bromethalin and I’m 48 hours in. Do you know how long it took for a recovery?

  2. Karen says:

    My jack ate some today and going they treaent of charcoal now. Did your dog survive? Any treatments you are aware of ?

  3. JG says:

    My 65 lb husky ate a large quantity of it that he found in the backyard of a house we just moved into. He showed all the symptoms listed above within a few hours and we had to have the vet euthanize him less than 15 hours later. Our Chihuahua also got into but luckily only ate a little. He presented with back leg tremors, fever, and some signs of neurological dysfunction. After 24 hours of induced vomiting, and then IV fluids he was released from the hospital. It took about a week but he luckily made a full recovery.

  4. John says:

    How concerned should I be about secondary poisoning with bromethalin (eg dog eats a dead rat)? Is there an option that offers the least risk of secondary poisoning?

  5. Roger says:

    Last Thursday evening our Norwich Terrier was fidgety. My wife took him to the vet Friday morning who suspected poisoning. My wife confirmed that a neighbor had placed bromethalin around their motor home. The vet administered charcoal and an anti seizure medication via IV. The vet called later in the afternoon and said he was not able to control the seizures and recommended putting the dog down and said if we really wanted to try to save the dog he would need to be moved to a more well equipped facility – Cornell or Univ of Penn. My wife started the four hour trip to U of P. I was in DC on business and started the drive up to meet her. The dog was admitted to emergency with tremors and seizures and symptoms so far advanced that the vet offered little hope. Again there is not a lot of survival data to go on. Our concern was binding the poison in the dogs system to reduce further damage to the nervous system. We decided on a course of IV lipids to bind the bromethalin. The vet said that they could treat the symptoms with an anti-convulsant (Keppra) and boluses of mannitol to eliminate excess water from the brain. If this sounds like a lot to go through – it is. And we did not know if this course of therapy was going to work. With so much unknown we decided to give it a try. Saturday morning my wife ans son made the trip to Penn to see the dog. In speaking with the vet, the dog had shown insignificant improvement and it really wasn’t appropriate to bring the dog home (without putting it down) despite the poor prognosis. I guess the key point to mention is that the dog had not shown any worsening of condition either. The vet felt that we would need to make a decision if nothing more than to spare the family the continued stress. So we decided to give the dog one more night in the ICU. The next morning we left the house early fully prepared to have to put the dog down and bring him home. On our way to U of P we received the message from the vet saying the dog, while not having regained normal neurological function, had shown marked improvement. In fact more so than any other adult dog they have seen with that type of toxicity. When we arrived, while the dog was not able to really move around physically, he was responsive. Monday he was further improved but needed to be taken off the mannitol – luckily no issues – and he was moved to an oral dose of Keppra. He tolerated the oral Keppra well and came home on Tuesday. Hopefully this will be of use to someone with a pet that they cherish. I cant fathom how poisons without antidotes could be put on the market.

    • marjorie says:

      Thank you very much for the information. I am living in fear that someone is going to poison my babies (dogs) . I am glad your baby survived.

      • Jessica says:

        We are in the midst of this right now. 80 lb boxer and 7 lb Chihuahua both ate tomcat rat poison. We got them to the vet right away and vomiting was induced and Rhett administered charcoal. Daisy (boxer) started having tremorsand was given valium, they transported her to an ER for the night. Wrecker (Chihuahua)is so far not having symptoms but they are observing him. We are told that prognosis is not good for Daisy and Wrecker is still not out of the woods.
        Did your dog make it with no long term affects?

        • Andrea says:

          How is your boxer? My 1 year 1 month old is in the midst of fighting.. never had seizures. Did not get to diagnose fast enough to induce vomiting or give active charcoal. 🙁 I need hope, haven’t given up. Hope your dogs are doing well. God bless

          • April says:

            How is your baby now? What symptoms and how long until you discovered it? I know 1 of my 2 dogs ate some around 9 am and we didn’t discover it until 7 pm. They didn’t offer to pump her stomach or do an enema. (The stomach Part I get. The enema they never mentioned and I just read online was an option). They did get charcoal. And now I’m supposed to give it every 8 yrs and watch for symptoms. I’m freakin gout. Would love to hear some positive outcomes! Thanks. God bless y’all. My pets are 2 havanese. Hannah and Harley-Grace.

  6. Christine says:

    How is your dog doing now? This sounds like what our dog is going through! (Still at hospital, day 2 after bromatheline ingestion but is improving). No seizures since last night. Feeling hopeful but worried about after effects!

  7. Gil Rosas says:

    Was there any side effects as of current to your pet from ingesting the bro bromethalin

  8. Kim says:

    My 3 yo pit bull at 42lbs ate approx 30 cakes of tom cat, almost a full bag 5 days ago. I didn’t know anything was wrong Nutella 24 hrs after he ate it. He currently is with the vet.. He cannot stand or control his blaster.. He has eaten nothing in 5 days. He has shown no improvement in 5 days. My vet is currently giving him IV fluids. I hope and pray for some good news today . His name is Dapper and I will post more when I have more. A poison with no anitodote is 3 rd world stupid

    • Niko says:

      Wow, that’s a huge dose of bromethalin. Your poor pup, I hope he makes it. I came upon this website, looking to see if there were any long term effects of bromethalin poisoning. Our two older dogs got into some a couple years ago. We didn’t know they had ingested it until one of them pooped it out (Tom Cat brand). They both went to the vet and got the Vitamin K/charcoal treatment. About two months later, they found some more Tom Cat elsewhere and again we went to the vet. One of the dogs was diagnosed with chronic pancreatitis about a year and a half ago, and the other dog has now developed really high ALP (liver enzyme) values.

  9. Niko says:

    I found this article interesting. It is dated 2014. Our dogs were treated with the Vitamin K/charcoal regimen in the two incidents we had. Vitamin K was used for anti-coagulant type rodenticides so I was surprised the vets also used it as an “antidote” for bromethalin. I’m quite sure neither of them used anything like Lipid Rescue. If your pet ingests bromethalin you might want to mention this treatment to your vet. “Antidote for bromethalin poisoning” https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3866846/

  10. Carla hall says:

    I am currently go through this with my 5lb. Chihuahua khloe she is only 11 months old. Didn’t know at the time of ingestion but noticed her not feeling well Tuesday night. We took her to vet Wednesday and it was bromethalin poisoning. She has had no seizures yet but is weak she still has an apitite but her water intake has completely stopped. The vet put her on steroids to help with the brain swelling and tramadol for pain. I’m giving her water through a syringe but when I do she starts screaming I don’t know what to do at this point. I love her deeply and can’t fathom being without her.

  11. Sandi Russell says:

    Hi. Four days ago my 6 pound yorkie developed a slight wobble. A few hours later he was injesting grass at a heavy rate and eating very quickly. Through the course of the day his tail dropped as well as his ears and he became unable to lift his leg to pee. That night he became unable to stand or move. He was rushed to the vet who thought he may have had a stroke. Luckily I was cleaning under my bed and remembered the ” pet proof” tomcat plastic maze style bait under my bed! I soon discovered that the mouse was tracking powder from the block to the entrance of the bait trap where my yorkie could easily lick it!!! I called my vet!! My Cody spent three days in doggie ICU with no appetite. Right side paresis, and tremors. He is home now but I am strongly considering a law suit against this ” pet proof” poison company. My vet said he sees at least 6 cases of this per year!

  12. Jeanne says:

    I’m suffering with you all! My six-year-old, 13 lb. mutt ingested poison a week ago, but we did not know, and it took three days, and an MRI to realize it was neuro damage after ingestion of TomCat cubes. She is brain damaged, but alive. They have her on steroids… but I want to add any naturopathic remedy that may give her a fighting chance. I saw mention of Vitamin K?! Help!

    • Stormy says:

      Our vet and Tomcat poison control said Vitamin K won’t help. That was the treatment for D-con poisoning that helped the blood to clot.

  13. Scruffysmom says:

    Help!!! My 13 lbs. Yorkie dog ingested a little bit of a tomcat cube containing brothalim… my car broke down and there is no way to reach a vet!!! How do treat her.. I tried making her vomit but she wont!!! She has no symptoms as of yet. I’m hoping I caught her in time. How long does it take for symptoms to show. It’s been 18 hrs. Since she ingested it!

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