What is arsenic poisoning?

Arsenic poisoning is the development of clinical signs after ingestion, skin contact, or inhalation of products containing a toxic dose of arsenic. Arsenic is a metal-like substance found naturally in rocks, soil, and water, but usually in very small, harmless amounts.

Arsenic is used in commercial products and practices, such as wood preservation, pesticides, and fuels. It is also in medicinal treatments for some parasites and cancers. Since the 1960s, using arsenic in commercial products and practices has declined, but it has not been eliminated. Today, arsenic poisoning in cats is exceedingly rare.

What causes arsenic poisoning?

The toxic dose of arsenic can vary greatly depending on the form of arsenic, the animal species, and the health status of the animal. Cats and humans are the most susceptible to arsenic poisoning. Weak, debilitated, and dehydrated animals are more susceptible than normal, healthy animals.

Once absorbed by the body, arsenic travels to all the organs, such as the liver, spleen, kidneys, lungs, and gastrointestinal tract. Once there, it mainly affects the vascular system (blood vessels), leading to swelling and bleeding in the organs.

What are the clinical signs of arsenic poisoning?

The clinical signs of sudden arsenic poisoning can vary depending on the dose. Clinical signs can include abdominal pain, salivation, vomiting, diarrhea, staggering, weakness, rapid and weak pulse, lethargy, low body temperature, collapse, and death. If arsenic exposure occurs on the skin, effects such as blisters, swelling, cracking, bleeding, and infections can occur.

“Clinical signs can include abdominal pain, salivation, vomiting, diarrhea, staggering, weakness, rapid weak pulse, lethargy, low body temperature, collapse, and death.”

Long-term or chronic exposure to lower amounts of arsenic can cause weight loss, due to decreased appetite, and nerve damage.

How is arsenic poisoning diagnosed?

Arsenic poisoning is diagnosed through history and clinical signs consistent with arsenic poisoning. Chemical analysis of the urine and gastrointestinal contents, as well as liver or kidney biopsies, may also be performed. Blood is not as useful for arsenic exposure because arsenic is cleared from the blood quickly. Hair samples may be helpful in testing for long-term exposure.

How is arsenic poisoning treated?

Arsenic poisoning treatment may vary depending on the type and time of poisoning. If your cat is not showing symptoms and the arsenic was ingested within four hours of examination, then inducing vomiting may be effective. Gastric lavage (removing contents of the stomach) may be considered by the veterinarian. Activated charcoal is not helpful in cases of metal poisonings.

Chelation therapy (chemical binding) can also be useful in arsenic poisoning cases. Two types of chelating compounds are commonly used: dimercaprol (BAL) and succimer (DMSA). Dimercaprol (BAL) itself is toxic, but if dosed appropriately, it can treat arsenic poisoning with few toxic effects. Succimer (DMSA) is less toxic, more effective and currently the preferred chelator. Call your veterinarian or Pet Poison Helpline, a 24/7 animal poison control center, at 1-800-213-6680 as soon as exposure is recognized to ensure that your cat receives the most appropriate recommendations for their exposure.

“Supportive therapy is a crucial part of treating arsenic poisoning.”

Supportive therapy is a crucial part of treating arsenic poisoning. Aggressive fluid therapy and rehydration is necessary and helps to remove arsenic from the body. Other supportive therapy includes antibiotics for secondary infections, anti-vomiting and anti-diarrheal medications, and a bland diet.

What care will my cat require after treatment for arsenic poisoning?

Your veterinarian should monitor the kidneys, the liver, and the electrolytes during and after treatment. If your cat makes a full recovery, no further aftercare is needed.