Arsenic Poisoning in Cats

By PetMD Editorial on Jun. 8, 2009

Arsenic Intoxication in Cats


Arsenic is a heavy metal mineral that is commonly included in chemical compounds for consumer products, such as herbicides (chemicals to kill unwanted plants), insecticides (chemicals to kill insects), and as wood preservatives. Most cases of toxicity occur in homes where such compounds are placed carelessly with open excess. Cats typically ingest such compounds accidentally. Toxicity can also occur over a long term, such as when cats are exposed to arsenic by eating grass that is regularly treated with herbicides.

Symptoms and Types

In case of acute exposure to arsenic, the following symptoms may be present in an affected cat:

  • Vomiting
  • Diarrhea
  • Abdominal pain
  • Lethargy
  • Fresh bright red blood in feces
  • Lying down with extreme exhaustion
  • Staggering
  • Body may feel unusually cold, especially at the extremities, such as the ears and limbs
  • Loss of consciousness
  • Death
  • In long-term (chronic) exposure symptoms may be subtle, such as poor appetite and weight loss


  • Ingestion of arsenic-containing compounds
  • Overdose of arsenic-containing drugs for treating heartworm parasite


You will need to give a thorough history of your cat’s health, onset of symptoms, and possible incidents that might have precipitated this condition. The background history is very important in the diagnosis of arsenic poisoning and your veterinarian will need to know about any arsenic-containing compounds you have at home. Many owners bring their cats to the veterinarian with complaints of a sudden and unexplained episode of vomiting. However, few owners report seeing their cats ingest arsenic-containing compounds, so this may not be the first cause that is apparent. Your veterinarian will perform a complete blood profile, including a chemical blood profile, a complete blood count, and a urinalysis. A sample of the stomach contents may also be necessary. Arsenic in the blood stream or stomach contents will confirm the diagnosis. In cases of chronic arsenic poisoning the level of arsenic in the body can be evaluated from a hair sample, as arsenic is deposited in the hair over a course of time.

If possible, you should collect a sample of the vomit or diarrhea to take to the veterinarian. This will help to speed the diagnostic process so that your cat can be treated before further damage is done.


Acute (sudden) arsenic poisoning is an emergency and time remains the crucial factor for a successful outcome. Vomiting plays a protective role in arsenic poisoning as it expels a large portion of the ingested poisonous material. However, if vomiting is not initiated in the immediate aftermath, your veterinarian will need to perform a gastric lavage (stomach irrigation) to wash out the stomach contents. As arsenic severely damages the liver and kidneys, dialysis is conducted for cats that are in a state of kidney failure due to arsenic poisoning. The main objective of treatment is to flush the poison out of the body; therefore fluid therapy and drugs promoting excretion are commonly employed.

Also, some compounds are known to chelate (bind) heavy metals such as arsenic, and are commonly used to bind arsenic that is still present in the body. Chelators work both by slowing the arsenic down before it can cross the blood-brain barrier, and by making it more water-soluble so that it can be washed from the body more effectively. Your veterinarian can employ such antidotes to enhance recovery in your cat. Your cat may need to be admitted into the veterinary hospital for a few days until it has stabilized and is completely out of danger.

Conversely, if you actually witnessed your cat consuming the poison, you can act quickly by inducing vomiting, but this must be done immediately following the event. If time elapses from the time of ingestion, only a veterinarian can treat your cat. For immediate first aid, if you are positive that your cat has ingested this toxic substance, 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. Do not use anything stronger than hydrogen peroxide without your veterinarian's assent. Because induced vomiting can be dangerous with some toxins, as some poisons will do more harm coming back through the esophagus than they did going down, 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 take it to a veterinary facility immediately.


Living and Management

After returning from the hospital, allow your cat proper rest and protect it from any source of stress. Follow your veterinarian’s guidelines for home treatment, such as medication and nutrition. Easily digestible food is often recommended for cats that are recovering from a poisoning.

Ensure that all sources of arsenic-compounds are secured or removed. If they must be kept in the home, be sure that they are out of reach of children and pets. Most problems are easily avoided if guidelines for handling and keeping such poisonous compounds are followed.

Keep an eye on your cat and if you observe anything unusual in its behavior, immediately consult your veterinarian. Unfortunately, in many cases of heavy intoxication, very few patients survive unless treatment is started very early.

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