Zinc Phosphide Poisoning in Cats

By PetMD Editorial on Apr. 6, 2009

Rat Poison Toxicity

Many people use commercial poisons to kill rodents, roaches and other common house hold pests. In order to be appealing to the pests they are aimed at, some poisons are made to taste good, making them appealing to dogs and cats as well.

Poisoning by pesticides and rodenticides is one of the most common household dangers to your cat. In this case, zinc phosphide poisoning will be explored as a potential culprit for your cat's health condition. Zinc phosphide is an ingredient used in some rat poisons, and is also commonly used by pest control professionals. One of the ways in which zinc phosphide effects the body is by causing a release of gases in the stomach, so that an animal that has ingested poison containing zinc phosphide will have breath smelling of garlic or rotten fish. Treatment is symptomatic (based on symptoms), and side effects of zinc phosphide poisoning can linger for several days after treatment.


  • Garlic or rotten fish odor in breath (with no recent history of eating either of these foods)
  • Rapid and/or difficult breathing
  • Blood in vomit
  • Depression
  • Weakness
  • Convulsions/seizures


  • Ingestion of Poisons
  • Rodent Poison
  • Cockroach poison
  • Pest poison
  • Any poison containing zinc phosphide
  • Ingestion of animal that has ingested poison (e.g., rodents)

If you suspect that your cat has come into contact with rat or mouse poison, and you are seeing some of the symptoms listed above, you will need to have your cat seen by a doctor before its health becomes critical. Keep in mind that if your cat goes out of doors at all there is the possibility that it will come into contact with rodent poison. The poison might be in a neighbor's yard, in a trash bag, in an alleyway, or the poison might have been ingested by a rat or mouse that your cat has caught and ingested parts from. Even if you do not live in an area where rats or mice are a concern, rodent poison may be used for other common suburban pests, like raccoons, opossums, or squirrels.


Your veterinarian will perform a thorough physical exam on your cat, taking into account the background history of symptoms and possible incidents that might have precipitated this condition. You will need to give a thorough history of your cat's health and recent activities. A complete blood profile will be conducted, including a chemical blood profile and a urinalysis.


If you are positive that your cat has ingested zinc phosphide through rat poison, you will need to encourage vomiting to expel the poison. For immediate first aid, try to induce vomiting with a simple hydrogen peroxide solution of one teaspoon per five pounds of body weight – with no more than three teaspoons given at once. This method should only be used if the toxin has been ingested in the previous two hours, and should only be given three times, spaced apart at ten minute intervals. If your cat has not vomited after the third dose, do not use it, or anything further, to try to induce vomiting. Induced vomiting can be dangerous with some toxins, and some poisons will do more harm coming back through the esophagus than they did going down. Do not use anything stronger than hydrogen peroxide without your veterinarian's assent, and do not induce vomiting unless you are absolutely sure of what your cat has ingested. If your cat has already vomited, do not try to force more vomiting.

A final word, do not induce vomiting if your cat is unconscious, is having trouble breathing, or is exhibiting signs of serious distress or shock. Whether your cat vomits or not, after the initial care you must rush it to a veterinary facility immediately.

There is no specific antidote for zinc phosphide poisoning. The most likely course your veterinarian will take is to do a lavage (an internal washing) of your cat's stomach with a five percent sodium bicarbonate solution, which will raise the gastric pH level and delay gas formation due to the swallowed zinc phosphide poison.

Living and Management

The health and survival of your cat depends on the amount of zinc phosphide poison ingested, and the time that elapses before treatment begins. Your cat may continue to suffer from symptoms of poisoning, like weakness and depression, for several days after treatment.


The best prevention is to keep all poisons (especially rodent poisons) out of your cat's reach. Carelessly placed poisons are a potentially fatal hazard that can be easily avoided.

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