Onions, onion powder, garlic and garlic powder are ingredients in some dog and cat treat recipes. Onions and garlic are in pot roast, meatloaf and other "people food" that some have been feeding pets for years.

But Internet sites, blogs and message boards run by pet lovers have been saying that onions are bad, although they generally don't back up those statements with any science.

I checked the ASPCA Animal Poison Control Center website (www.aspca.org) to see what their veterinary toxicologists say. The site's list of potentially deadly foods includes chocolate, grapes, raisins, avocado and the sweetener Xylitol, used in sugarless chewing gum, candy and baked goods. There was no mention of onions.

So I landed a telephone interview with Safdar Khan, director of toxicology research at the ASPCA Poison Control Center.

To sum up his comments, large amounts of onions or garlic can cause damage to blood cells -- i.e., a form of anemia -- in dogs and cats. Cats are more sensitive to onions and are more at risk. Garlic has the same effect as onions. A large amount of onions could cause serious problems, possibly death, in 1-4 days, he said.

"Large amount is a relative term," Dr. Kahn said, and veterinarians and researchers don't know how much would be too much. He added that no one knows the long-term effects of small amounts of onion and garlic eaten over a long period of time.

Is there a problem with very small amounts of onion powder and garlic powder used in treat recipes?

"We are not sure," Dr. Kahn said. "Once again, we don't know the long-term effects."

Every pet will not get sick from eating onions or garlic. For unknown reasons, Japanese breeds are more sensitive to onions, including Akita, Japanese chin and Shiba Inu dogs, and Japanese bobtail cats.

No pet owner would know if their pet is sensitive to onions until the pet eats them. So to be safe, dogs and cats should not eat onions or other foods on the potentially deadly list.

By the way, the sweetener Xylitol is not harmful to people or to cats, Dr. Kahn said.

The American Veterinary Medical Association list of foods to avoid includes coffee grounds, yeast dough, macadamia nuts, fatty foods, tea, alcohol and salt, as well as all of the foods on the ASPCA list.

If your dog or cat gets into any of the dangerous foods, you can call the Pittsburgh Poison Center at Children's Hospital. The service is free, and answers questions about pets. The number is 1-800-222-1222.

If the Pittsburgh Center cannot handle your problem, you will be referred to the ASPCA hotline: 1-888-426-4435. Get out your credit card. The cost is $65.

Go to www.aspca.org for further information about the Animal Poison Control Center's top 10 poisons of 2009. The No. 1 poison was human medications, with 45,816 calls out of the 140,000 the center received. People food was No. 3 with 17,453 calls.

Back by popular demand -- another chance for dogs to swim in the Dormont Pool. They're calling it the 2nd Annual Labor Day Doggy Dip. Last year's event was a big hit with nearly 300 dogs.

An open dog session for canines of all shapes and sizes will be 5:45-8 p.m. on Monday. This year a special session has been added for dogs 30 pounds and smaller from 4 to 5:30 p.m.

Proceeds benefit the Dormont Pool and the Western Pennsylvania Humane Society. The event also will have games and raffles.

Cost is $15 per dog the day of the event or $10 for advance registrations made online, until noon Sunday: www.pahumane.ejoinme.org/MyPages/LaborDayDoggyDipFlyer/tabid/224809/Default.aspx.

They don't have shelters and they don't have big budgets or salaried professionals on their staffs, but small rescue groups do so much good.

Such a rescue is FosterCat Inc. in Pittsburgh. Since 1999, volunteers have provided foster homes and permanent homes for more than 1,000 cats and kittens. The network currently has 25 foster homes.

FosterCat's 5th annual spaghetti fundraising dinner is 4 to 7 p.m. next Saturday at Wallace Memorial Presbyterian Church, 1000 Greentree Road, Green Tree. Take-out orders are available. There's also a Chinese auction, 50-50 raffle and cat toys for sale.

Tickets are $9 for adults and $4 for children and can be purchased at www.fostercat.org or by calling 412-481-9144.