How To Protect Pets From Rodenticides

By: Whitney Hall, DVM

TVMA Member
McAllen, TX.

Published May 2017

A rodenticide is a chemical designed to kill mice, rats and other rodents as a pest control measure. Rodenticides work by disrupting or stopping normal bodily functions like clotting and maintaining fluid or mineral balance. These normal responses are similar in all mammals, so rodenticides can cause the same toxicities in other species, including dogs, cats, pocket pets and even children.

Because rodenticides are used frequently in open areas where people are trying to eliminate or reduce the pest (wild rodent) population, pets can accidentally ingest them. Additionally, there are documented cases of intentional pet poisoning using rodenticides.

If you think your pet has ingested a rodenticide or is showing any of the clinical signs discussed below, you should consult with your veterinarian or an emergency clinic immediately and have the packaging or a list of chemicals available.

Early Treatment Improves Results

Pets have a much better chance of responding to treatment if it is started early. Removal of the rodenticide from the intestinal tract is the first step if your pet recently ingested a rodenticide and has not yet shown clinical signs. Your veterinarian may recommend inducing vomiting, gastric lavage, administration of activated charcoal and/or enemas. (It is not recommended to attempt these procedures at home without consulting a veterinarian.)

Diagnostic Tests and Treatment Options

If your pet is showing clinical signs of rodenticide toxicity (indicating that the rodenticide absorbed into the bloodstream and is affecting other organs), it is more difficult to treat. Your veterinarian will likely recommend treatment to control any clinical signs, hospitalization and blood tests to monitor for clinical signs and response to treatment. Testing for a specific rodenticide in your pet’s body requires specialized testing at a reference laboratory, which usually takes too long to be helpful but can be performed for confirmation of ingestion.

Rodenticides Can Lead to Excessive Bleeding

Anticoagulant rodenticides including warfarin and other prescription blood thinners impede clot formation. When clots aren’t formed, significant bleeding can occur. It may take two to three days or longer for bleeding to occur after the ingestion of an anticoagulant rodenticide. Clinical signs can be different depending on where the bleeding occurs and may include difficulty breathing, nose bleed, skin or eye bruising, blood in urine or feces, pale gums or weakness. Specific treatment for this type of rodenticide ingestion is administering Vitamin K1 so the body resumes forming clots until the rodenticide exits the body. This treatment can be started before clinical signs emerge if your veterinarian thinks your pet may be at risk for bleeding. Some pets also may require transfusion of blood products if they experience severe bleeding.

Extra Fluid Causes Neurological Problems

Bromethalin is a different class of rodenticide that causes extra fluid (edema) to accumulate in the brain and spinal cord, changing how the brain and nerves communicate with the body. Clinical signs may develop within hours after ingestion or three to four days later and can include weakness, loss of balance (ataxia), changes in behavior, seizures or coma. There is no specific treatment for Bromethalin toxicity, but a veterinarian will likely recommend sedatives, anti-seizure medication and/or muscle relaxants.

High Levels of Vitamin D Reduce Function of Major Organs

Other rodenticides contain high levels of Vitamin D. Although this vitamin is necessary for normal body function, high levels cause mineralization of soft tissues including muscles, kidneys, heart and lungs, leading to organ failure. Clinical signs are usually seen within one to two days of ingestion. While there is no specific treatment for Vitamin D toxicity, veterinarians usually recommend IV fluids and medications to decrease levels of calcium in the body.

Other rodenticides on the market include Strychnine (gopher and mole baits), sodium monofluoroacetate (livestock collars) and zinc phosphate.

Alternative Methods of Rodent Control

Several alternative methods of rodent control are available. Before purchasing and using toxic chemicals around your pets, consider the following options.

  • Keep your house (garage, shed, barn, etc.) clean, free of garbage and in good repair.
  • Use live traps that work without any chemicals. These traps have to be checked regularly, and any rodents that are caught have to be released or disposed of according to local regulations.
  • Use snap traps that work without chemicals but quickly kill the rodents. These also must be checked regularly, and the rodents must be disposed of properly.

If you still use rodenticides, take steps to prevent your pets from accessing these toxins.

  • Follow all safety instructions on the package.
  • Place the rodenticide in a pet-proof (and child-proof) container in an area that pets and children cannot access and you check regularly.
  • If you see your pet in areas that contain rodenticides, immediately restrict access to these areas or move the rodenticides.
  • Replacement bait pellets or blocks should also be kept in a pet-proof location, preferably behind multiple barriers such as a metal box and a closed closet door.
  • Record the active ingredients of all chemicals used in and around the house so you can report them to your veterinarian if you suspect your pet has ingested anything. Talk with your pest control service as well to record any chemicals they may use.

Talk with your neighbors about these options as well, especially if you have pets that roam outside. Proper use of rodent control measures is important to the health of your pet. Talk with your veterinarian about more ways to keep your pet safe from rodenticides and other toxins.

Whitney Hall, DVM, is a graduate of Texas A&M College of Veterinary Medicine who lives in McAllen, Texas. Dr. Hall practices at Veterinary Wellness Center.