By Dr. Becker
Recently a 3-year-old Pug named Bruce in Overland Park, Kansas discovered a tin of sugar-free Mentos and helped himself. Within a half-hour, Bruce was lethargic. Fortunately, his owner connected the dots between the Mentos and Bruce's rapidly deteriorating condition.
After calling the veterinarian's office, as he picked Bruce up to rush him out to the car, the dog went limp. Once at the vet's office, he had a seizure. The mints Bruce had eaten contained xylitol, a sweetener that is highly toxic to dogs. It's a sugar alcohol extracted from corn and corn fiber, birch, raspberries and plums.
Xylitol is used to sweeten a wide range of products, including sugar-free gum and mints, nicotine gum, chewable vitamins, certain prescription drugs, dental hygiene products and baked goods.
Xylitol can also be purchased in granulated form as a sugar replacement to sweeten beverages, cereals and other foods.
Fortunately for Bruce, the veterinary staff quickly treated him with glucose water and monitored him closely. He survived the initial crisis, but they don't know yet if there has been permanent damage to his liver.
The Number of Products Containing Xylitol Is Exploding
Xylitol poisoning in dogs is reaching epidemic proportions according to some sources. The sweetener is being used in an ever growing list of products because it's as sweet as sucrose, but with only two-thirds the calories of sugar.
It's less expensive than other sugar substitutes, tastes better and causes little if any insulin release in humans.
Just a few years ago, xylitol could be found in less than a hundred products in the U.S., primarily limited to sugar-free gums, candy and foods. Today it can be found in a wide range of health and beauty products, food products, over-the-counter drugs and supplements and prescription medications.
Until fairly recently, xylitol was found primarily in products not normally given to dogs. Poisonings were usually the result of dogs like Bruce sampling human foods, candy or gum on the sly.
However, xylitol is now being found in certain peanut and nut butters. As most dog guardians know, our pets love these creamy butters. Many people use a dab of peanut or nut butter to hide pills or supplements they give to their dog, or they fill a Kong with the gooey stuff as a special treat.
Peanut and Nut Butters Containing Xylitol
Dr. Jason Nicholas, who runs Preventive Vet, has compiled a list of nut butters containing xylitol:1
✓ Go Nuts, Co.
Almond Butter - Chocolate Almond Butter
Peanut Butter - Dark Chocolate Mint
Peanut Butter - Natural Chocolate Flavor
Peanut Butter - Natural Flavor
Peanut Butter - Organic Maple Flavor
✓ Krush Nutrition
Nutty By Nature Peanut Butter Brownie Batter
Nutty By Nature Peanut Butter Cookie Dough
Nutty By Nature Peanut Butter Snickerdoodle Cookie
Nutty By Nature Peanut Butter Thick & Creamy
✓ Nuts 'N More®
Almond Spread - Almond Butter
High Protein + Almond Spread - Almond Butter
High Protein + Almond Spread - Chocolate Almond
High Protein + Almond Spread - Cinnamon Raisin
High Protein + Peanut Spread - Chocolate Peanut
High Protein + Peanut Spread - Peanut Butter Flavor
High Protein + Peanut Spread - Pumpkin Spice
High Protein + Peanut Spread - Toffee Crunch
Peanut & Protein Spread - Sesame Cranbutter
Peanut Spread - Peanut Butter Flavor
Peanut Spread - Toffee Crunch
✓ P28 Foods
High Protein Spread - Almond Butter
High Protein Spread - Banana Raisin
High Protein Spread - Peanut Spread
High Protein Spread - Signature Blend
✓ Protein Plus PB
Hank's Protein Plus - Almond Butter
Hank's Protein Plus - Banana
Hank's Protein Plus - Caramel Pretzel
Hank's Protein Plus - Chocolate Chip
Hank's Protein Plus - Coconut
Hank's Protein Plus - Honey Maple
Hank's Protein Plus - Plain
Hank's Protein Plus - Snickerdoodle
These are specialty nut butters sold primarily in nutrition stores and online, but the fact that xylitol is now being used in these products is a heads-up for dog parents everywhere of the importance of reading ingredient labels. It's probably just a matter of time before more mainstream peanut and nut butters also contain xylitol. As Dr. Ahna Brutlag, associate director of veterinary services for Pet Poison Helpline explains the seriousness of the situation:
"First, dogs fed straight peanut butter as a treat or fed treats baked with xylitol-containing peanut butter may certainly be at risk for harm.
Second, a dog that nabs the entire jar of xylitol-containing peanut butter and happily gorges on his or her treasure without anyone knowing could quickly become extremely ill. If this occurred during the day while the owners were not home, it's possible the dog could die before people returned."2
You should be aware of any product in your home containing xylitol, and especially anything you might consider offering to your dog.
Xylitol-Related Dog Poisonings More Than Doubled in 7 Years
Each year as the number of products containing xylitol expands, sadly, so do the cases of poisoning in dogs. In 2007, the first year the ASPCA Animal Poison Control Center (ASPCA-APCC) started tracking cases of xylitol toxicity in dogs, the Center received 1,764 calls. In 2014, they handled 3,727 xylitol calls.3
That's over a 200 percent increase in just 7 years, and includes only the cases called into the ASPCA-APCC. There are other animal poison control centers that receive calls, as well as unreported cases of xylitol-related illnesses and deaths.
The Toxicity of Xylitol Depends on the Species and Dose
Although xylitol is safe for humans, the sweetener's effect varies by species. In people, rhesus monkeys, rats and horses, xylitol causes little to no insulin release. However, it has the oppositeeffect on dogs, ferrets, rabbits, cows, goats and baboons. Its effect on cats is unknown.
Humans absorb xylitol slowly, and the sweetener when ingested orally is absorbed at from 50 to 95 percent. However, in dogs, xylitol is rapidly and fully absorbed within about 30 minutes. Just a small amount of xylitol can cause a dangerous insulin surge and a rapid drop in blood sugar.
The toxicity of xylitol in dogs is dose-dependent. The dose required to trigger hypoglycemia (low blood glucose) is approximately 0.1 grams/kg, while the amount needed to cause liver failure is about 0.5 grams/kg. Most gum and breath mints typically contain .22 to 1.0 gram of xylitol per piece of gum or mint.
This means just a single piece of gum or one mint may cause hypoglycemia in a 10-pound dog. For more detailed information and graphics on how much xylitol is dangerous to different sized dogs, as well as a comparison of xylitol versus chocolate toxicity in dogs, take a look at this Preventive Vet page.
Determining the Amount of Xylitol in a Product
Currently, product manufacturers aren't required to list the quantity of xylitol on package labels, and while some companies will reveal the amount in their products, many are reluctant to do so.
In some cases, you might be able to use the placement of xylitol on an ingredient list to estimate how much is in the product. In the U.S., ingredient lists for foods must be organized in descending order based on weight. The ingredient weighing the most is at the top of the list.
In most chewing gum ingredient lists, xylitol appears in fourth or fifth place, making it clinically insignificant. But if it appears as one of the first three ingredients, extreme caution should be taken. In fact, I recommend dog guardians avoid or very carefully secure any product that contains any amount of xylitol, no matter how small.
When it comes to medications and dietary supplements, U.S. regulations do not require manufacturers to list xylitol by name on package labels. This is because the sweetener is often categorized as an "inactive" or "other" ingredient, and such ingredients don't have to be listed in order by the amount contained in the product.
To confuse matters further, when xylitol is named in these products, it is often part of an alphabetized list, which could lead pet owners to assume — perhaps in error — that there is a very small amount in the product. That's why it's best, in my opinion, to either avoid or very carefully store any product that contains xylitol in any amount. Dr. Nicholas has compiled a fairly comprehensive list of products containing xylitol here.
Symptoms of Xylitol Poisoning and Required Treatment
Symptoms of xylitol intoxication in dogs include vomiting, weakness, lethargy, loss of coordination, seizures and collapse. Hypoglycemia is usually evident within an hour or two after a dog ingests xylitol, but symptoms are occasionally delayed for several hours.
Treatment depends on how quickly it is given. Vomiting is induced in cases where the xylitol has just been ingested. Once a dog develops hypoglycemia, IV dextrose must be administered until the animal can self-regulate his blood glucose concentrations, which typically takes from 12 to 48 hours.
In dogs who ingest enough xylitol to cause liver toxicity, liver enzymes must be closely monitored, as evidence of hepatic necrosis can show up one to two days after ingestion. Should the liver begin to fail, the dog will require IV fluids, dextrose, hepatoprotectants (substances to help support and repair the liver), and regular monitoring of blood clotting activity.
When xylitol exposure is caught early in a dog and treated effectively, the prognosis for a full recovery is excellent. The prognosis for dogs that develop hepatic failure is less optimistic.