Is Zinc toxic to cats?

When zinc-containing objects enter the acidic stomach environment, the metal breaks down and is absorbed into the bloodstream, leading to the destruction of red blood cells and potential organ failure.

Treatment follows the same steps as in dogs. The vet takes X-rays to look for a metal object and runs blood tests, and may give an acid reducer to cut zinc absorption until the object is out. Activated charcoal isn't used, because it doesn't bind zinc. The object is removed with an endoscope (a camera tube passed through the mouth) or by surgery. Care can include a drip (IV fluids), anti-nausea medicine, stomach protectants and blood transfusions for anemia. In the published case, vets removed the zinc nut from the outlet of the cat's stomach with an endoscope, and the cat also needed a blood transfusion and a feeding tube for 6 days. Chelation, a treatment that binds zinc, is controversial: vets consider it only if a pet isn't recovering as expected after the object is removed.

None of the sources we checked gives survival figures for cats. With early diagnosis and treatment, the outlook is usually good for animals with zinc poisoning, according to the Merck Veterinary Manual. In the published case, the cat recovered after the nut was removed and with supportive care: its signs and anemia cleared, and its blood zinc level had fallen 7 weeks later.

• Coins. Most cases of zinc poisoning in pets come from dogs swallowing pennies. US pennies minted after 1982 have a zinc core under a copper plating: they contain 97.5% zinc, about 2,440 mg of zinc per penny. In a study of 55 dogs poisoned by swallowed metal objects, US pennies minted after 1982 were the most common source (67.3%). The Merck Veterinary Manual adds that other coins in circulation around the world also contain zinc, without naming them.
• Zinc oxide creams and lotions: diaper rash creams (such as Desitin), sunscreens and calamine lotion. Zinc oxide is a less toxic form of zinc, and the Merck Veterinary Manual rates swallowing a cream once as a low risk that rarely causes more than stomach upset, depending on the amount.
• Throat lozenges, some dietary supplements, anti-dandruff shampoos, deodorants and mouthwash, which may contain forms of zinc that Pet Poison Helpline describes as more toxic than zinc oxide. The Merck Veterinary Manual rates a one-time swallow of zinc lozenges or supplements as a low risk that typically causes stomach upset.
• Metal hardware: nuts, bolts, nails, screws, staples, wire and anything galvanized (coated with zinc to stop rust). A cat was poisoned by a nut made mostly of zinc, from a screw used in flat-pack furniture. Zinc is also found in car parts, some soldering products and newer batteries.
• Game pieces, toys and small household items: many-sided game dice, older board game pieces, toys, zippers, jewelry, undergarment hooks, and zinc-coated garland and tinsel.

• Keep coins in a closed purse, jar or drawer, and pick up any that fall on the floor.
• Store nuts, bolts, screws and other small hardware, including the parts that come with flat-pack furniture, where pets can't get them.
• Pick up game pieces and dice, jewelry, hair ties and other small objects your pet could swallow.
• Keep diaper rash creams, sunscreens and other zinc oxide products closed and out of reach. A dog can squeeze a tube empty without piercing it.
• Ask your vet before putting a zinc oxide cream on your pet. In one reported case, a Maltese developed anemia after its owners applied a 'max strength' 40% zinc oxide diaper cream to it every day for a week.