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Sweetener used in some peanut butter brands could be deadly for your dog

Dr. Virginia Sinnott (pictured checking on a patient in Angell Animal Medical Center’s Emergency and Critical Care unit) says about half of the clients who come in for xylitol poisoning aren’t aware of the potential dangers. Suzanne Kreiter/Globe staff

The next time you hide your dog’s flea pill in peanut butter, it might be a good idea to check the back of the jar first.

Some nut butters contain xylitol, a sugar alcohol used as a sweetener. While harmless to humans, xylitol is over 100 times more toxic than chocolate for your furry best friend and can be fatal if accidentally consumed. When dogs ingest the sweetener, their bodies release insulin because it cannot recognize the difference between sugar and xylitol, causing their blood sugar to drop. This can lead to vomiting, lethargy, seizures, and possibly liver failure in the case of larger doses, according to veterinarians.


Dr. Virginia Sinnott, of Angell Animal Medical Center’s Emergency and Critical Care unit, said xylitol became a trendy sugar substitute in bakeries about 9 years ago. Two years ago, food companies began adding it to peanut butters so they could label their products as no sugar or low sugar. There are currently five peanut butter brands that use xylitol: Go Nuts Co., Krush Nutrition, Nuts ‘N More, P28 Foods, and Protein Plus PB.

“We’ve seen an increase in the number of calls about xylitol,” Sinnott said. “People become concerned after giving their dogs a few licks of peanut butter for a pill. Most of the time, the dog does not ingest too much because there’s not much sugar in the product, but it’s always good to check.”

The most common way dogs accidentally consume xylitol? Chewing gum.

Some chewing gum brands, such as Trident and Ice Breakers, have a higher concentration of the sweetener, making it more dangerous for dogs. Packs of chewing gum in purses and car cup holders are particularly accessible for your canine pals, according to Sinnott.

Even though xylitol is extremely toxic for dogs, not all pet owners know which foods it can be found in and what symptoms it can cause. Sinnott said about half of the clients who come in for xylitol poisoning aren’t aware of the potential dangers.


Paula Connito, a nutritionist and dog owner, said she avoids buying anything with preservatives or sweeteners. She knew what xylitol was, but didn’t realize that peanut butter brands had started using it as well.

“My vet never brought this up to me as a concern,” she said.

Neha Hamzah, the owner of a 4-month-old Cockapoo, said she liked filling her puppy’s toys with peanut butter and freezing them.

“I bought dog friendly peanut butter from a pet store, but had no idea other peanut butters could be deadly,” she said.

Sinnott said she expects to see an increase in the number of peanut butters that contain xylitol in the next few years, but hopes that consumers will provide enough feedback that will make the sweetener go away.

Most dogs who eat a lick or two of peanut butter don’t experience liver failure, but Sinnott said it’s important to monitor their blood sugar levels until they return to normal. She also stressed that there isn’t any current research about how small doses of xylitol can affect dogs over time.

“Dogs are very acrobatic when they’re motivated, so if you choose to have products that contain xylitol in your home, be sure to keep them in a closed cabinet,” Sinnott said.

Bethany Ao can be reached at Follow her on Twitter @bethanyao.