PRODUCTS SWEETENED WITH XYLITOL CAN BE TOXIC TO DOGS
By Bernadette Mauch
Xylitol, or as it is also called, birch sugar or wood sugar is a sugar alcohol or polyol and it is a widely used sugar substitute. The ASPCA Animal Poison Control Center in a press release dated August 21, 2006, cautions animal owners that xylitol, which is found in certain sugar-free products, such a chewing gum, candies, baked goods, toothpastes and other products can potentially cause serious and even life-threatening problems for dogs. A clinical report appearing in the October 1, 2006, Journal of the American Veterinary Medical Association (JAVMA) discusses the same problem with xylitol.
Xylitol tastes as sweet as conventional sugar, but only contains two-thirds the amount of calories. Because it causes little insulin release in humans, xylitol is a good substitute for diabetics and low carbohydrate dieters. In people, xylitol is very safe and consumption of large quantities will only cause diarrhea. In dogs, however, they can develop serious and even life-threatening problems. It is still unknown how cats are affected by xylitol.
Xylitol appears to be the only "sugar alcohol" that has detrimental effects in dogs. Other sugars, such as sorbitol and mannitol, and artificial sweeteners are generally regarded as safe. Even large amounts ingested should result only in watery diarrhea.
Dogs ingesting items sweetened with xylitol could develop a fairly sudden drop in blood sugar (hypoglycemia), vomiting, depression, loss of coordination and seizures. These signs can develop quite rapidly, at times less than 30 minutes after ingestion of the product. If an owner suspects that their dog has eaten a product containing xylitol (even just a couple of pieces of sugar-free gum), it is crucial that the owner seek veterinary treatment immediately or contact the ASPCA Animal Poison Control Center for immediate assistance. To reach the ASPCA Animal Poison Control Center call (888) 426-4435. There also appears to be a strong link between xylitol ingestions and the development of liver failure in dogs. In dogs ingesting smaller amounts of xylitol, the clinical signs could be delayed as much as 12 to 24 hours after ingestion. In cases of mild elevation of liver enzymes the dogs are able to fully recover. Others develop acute liver failure which may lead to jaundice, bleeding under the skin or in the gastrointestinal tract, shock and possible death. It is important to remember that even if your pet doesn't develop signs right away they may develop them later. Since this is such a relatively new problem, it seems that many veterinarians aren't yet aware of xylitol poisoning.
How much xylitol causes toxicity? Studies have shown that greater than 0.22 grams per pound of weight can cause hypoglycemia and greater than 1.1 grams per pound of weight can cause liver damage. Chewing gums that are largely or only sweetened with xylitol contain about 1 to 2 grams per piece of gum. Therefore, one or two pieces of gum could cause symptoms in a dog weighing 22 pounds. One cup of xylitol powder, used in home-baked goods, weighs about 190 grams. There is no known antidote or reversal drug. If your pet ingests any amount of xylitol, contact your veterinarian immediately and be sure to have the label contents available so you can determine the amount of xylitol your dog may have eaten. Because the onset of signs can be very rapid, induction of vomiting is only recommended when the pet is not showing symptoms.
Supportive care is paramount to survival in xylitol poisoning. Intravenus fluid therapy is important to restore and maintain hydration, as well as to prevent or treat shock. Hypoglycemia can be prolonged for several days, therefore it is imperitive that blood sugar values be monitored closely. Liver values should be followed daily for at least 72 hours.
In 2003, the ASPCA recorded only three xylitol poisonings. That number skyrocketed to 70 in 2004. In 2005, there were more than 170 cases and between January and August, 2006, there had already been 114 cases reported. What caused the increase? Experts believe the reason is the increased availability of products containing xylitol as a sweetener. To prevent xylitol poisoning, dog owners should be aware of products that contain xylitol as a sweetener and keep these products out of the reach of their dogs. Besides the items mentioned above, smoking cessation aids such nicotine gum, sunscreen and some vitamins and diet supplements may also contain xylitol. If your dog accidentally consumes something he's not supposed to, be sure to read the list of ingredients on the product label to find out if it contains xylitol.
In researching xylitol, I came across a web site which had a story about someone's 24 lb. Dachshund, Chloe. The owner came home from work and ten minutes later saw her dog with her head inside her friend's purse. The dog had a guilty look on her face so she looked closer and saw a small package of sugar-free gum. It contained xylitol. She had recently read that sugar-free gum could be deadly to dogs. She immediately took Chloe to the vet. They started an iv with dextrose. About two hours later the vet called and said that the contents of her stomach contained 2-3 gum wrappers and that her blood sugar had dropped from 90 to 59 in 30 minutes. Chloe was taken to a critical care hospital and the ASPCA doctors directed Chloe's doctor on her treatment. They continued the iv and monitored her blood every other hour and then in 2 days tested her liver function. Chloe spent most of the weekend in the critical care hospital. After her blood sugar stabilized she went home. They ran all the tests again before they released her and there was no sign of liver damage. Had the owner not seen her with her head in the purse, Chloe probably would have died and they never would have known why.
For more information about items that can be harmful to your pets, visit the ASPCA web site's Animal Poison Control Center at www.aspca.org. It has lists of: Foods to Avoid Feeding Your Pet; Warm Weather Hazards; Medication; Cold Weather Hazards; Common Household Hazards, Holiday Hazards; and Non-toxic Substances for Dogs and Cats (which may cause mild gastrointestinal upset). Also, www.pedigree.com (nutrition) explains what some of these items can do to your pet.
Be sure to keep a list handy of emergency telephone numbers for medical care for your pets and for yourself and your family. Be sure to list alternate numbers and "after hours" numbers, too.
Sources of information:
www.aspca.org - press release dated August 21, 2006
www.avma.org - press release dated October 1, 2006
www.limaohio.com - "Sugar substitute not so sweet to dogs" by April Shattuck, Jan. 14, 2007
www.associatedcontent.com - Products with Xylitol as a Sweetener Harm Dogs byAmy Francisco