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Secondhand smoke causes cancer in pets

Secondhand smoke greatly increases the risk of cancer in pets. Dr. Lee Pickett explains the cause deeper and the potential cancer risks here.

Secondhand smoke causes cancer in pets

Q: We lost our cat to throat cancer. Both my husband and I smoke. Could our secondhand smoke have caused her cancer?

A: Unfortunately, the answer is yes. Secondhand smoke quadruples the risk of two kinds of cancers in cats: oral squamous cell carcinoma and lymphoma, also called lymphosarcoma.

Cats are particularly sensitive to the toxins in secondhand smoke because they inhale – and ingest – them.

No, they don’t chew their humans’ cigarettes. Instead, the smoke particles settle on the furniture and carpet where the cats lie. When they groom ourselves, they ingest the toxins on their fur.

Oral squamous cell carcinoma is common in cats living with people who smoke only one to 19 cigarettes per day. This cancer forms on the gums, under the tongue or in the back of the throat. Treatment usually is unsuccessful; fewer than 10 percent of affected cats are alive one year after diagnosis.

The other cancer that frequently occurs in cats that live with smokers is lymphoma, a cancer of the lymphatic system. The most common location is the gastrointestinal tract.

I send my condolences to you and your husband.

Lee Pickett, V.M.D. practices companion animal medicine in Pennsylvania. Contact her at

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