Ask Dr. Richards: 02/05

Sometimes my cat eats toilet paper! Im worried that this will hurt her. Is toilet paper poisonous? How can I get her to stop eating it?

Im unaware of any substances in toilet paper (like perfumes or dyes) that would be particularly poisonous to cats. However, should your cat eat enough of the stuff, Im concerned that a wad of it could collect somewhere in her stomach or intestines and cause an obstruction. Nevertheless, Ive not seen any reports of such cases in the veterinary literature. Interestingly, there have been cases of intestinal obstructions resulting from toilet paper ingestion in people; apparently these folks were operating under the illusion that eating toilet paper would help them lose weight!

Swallowing small amounts of toilet paper shouldnt be harmful, but its probably best to try to prevent her from eating it, at least to the extent that youre able to do so. Perhaps the simplest way is to prevent her from having access to it.

Something as simple as keeping the bathroom door shut when nobody is using it might do the trick, or you might look for a toilet paper holder designed to close over the open roll. 

Its not clear to me whether shes intentionally consuming it (the term we use when cats eat non-food substances is pica) or whether shes simply playing with the paper and then getting it in her mouth and swallowing it. If shes intentionally eating it, I have a couple of suggestions. First, you might consider growing a kitty garden for her. Letting her chew and eat fresh grass growing in an indoor planter is a safe alternative, and it might satisfy her need for dietary bulk. Second, you might try feeding her a commercial cat food with higher fiber content (like a light or weight-loss formula).

But some cats just love to play with toilet paper. I knew a cat that liked to grab the end of a roll in her mouth, then run across the room pulling yards of the stuff behind her. If yours is such a kitty, try offering her other play alternatives. Fishing-pole-and-lure-type cat toys are excellent because theyre fun for both you and your kitty.


I recently heard that onions are toxic to cats and dogs. Does this mean raw or cooked onions? Our cats love scalloped potatoes that contain ham and cooked onions. Are we harming them by feeding them their favorite treat?

Just about anything can be toxic if given in high enough quantities, but even in small quantities, onions can be poisonous to cats (and to dogs, horses, sheep and cows).

Onions contain thiosulfate compounds that damage hemoglobin, the red, oxygen-carrying pigment in red blood cells. The damaged hemoglobin clumps together and forms masses called Heinz bodies, which are visible inside the blood cell if examined under a microscope. If the Heinz bodies are large enough, they cause the cell to be destroyed. 

These thiosulfate compounds can directly damage the cell membrane, too, and if the quantity of onion consumed is great enough, hemolytic anemia (too few red blood cells as a result of cellular destruction) can be the consequence. It seems that cooking doesnt make any difference; the compounds remain capable of harming hemoglobin whether the onions are raw, cooked, or even powdered.

Onion toxicity is usually not high on the list of concerns for cat lovers, probably because onions arent thought to be a feline culinary delight.  Gardeners neednt fear that onion-craving cats will ravage their onion patches. But it does become a concern if cats are fed food that contains onions or onion powder. Several years ago, veterinarians noted that a human baby food (often fed to cats that are sick and refuse to eat anything else) contained onion powder as a flavor enhancer.  When fed to cats, the baby food induced Heinz body formation and, in some cases, the cats became anemic. After it was discovered that the onion powder was causing anemia in the cats, the manufacturer of this particular product removed onion powder from all of its diets. 

I believe most other baby food manufacturers have followed suit, but if a cat must be fed baby food for a medical reason, it would be prudent to check the label to make sure that onion powder is not a constituent.  Some store-brand cat foods may contain onion powder too, but the quantity present is below the level reported to be toxic to cats.

So what about your scalloped potato-loving felines? The treat is probably okay if given in moderation and if it wont contribute to obesity or any other medical problems.  But to be on the safe side, leave out the onions.