January 2009 - Happy New Year!
The Doctors and Staff of the Merrick Veterinary Group would like to wish everyone and their pets a Happy and Healthy New Year. Please check back regularly for all new monthly updates, and feel free to browse the archives in our Veterinary Library for last year's updates as well.
Sugar substitutes are big business. Less sugar can mean weight loss, improved health, diabetic control, and even reduced tooth decay. The quest for products that can sweeten and cook like sugar is ongoing. Xylitol is common sugar substitute, especially when it comes to sugarless gum. Not only does xylitol offer sweetness without calories, it also has antibacterial properties in the mouth so as to reduce periodontal disease and has been found to have far reaching health benefits in other areas of the body. Xylitol may help with osteoporosis, prevention of ear and throat infections, and may reduce the risk of endometriosis, uterine fibroids, and even breast cancer.
Sounds wonderful, and maybe it is - if you are a human. If you are a dog, xylitol is potentially lethal.
Two Deadly Effects of Xylitol
In the canine body, the pancreas confuses xylitol with real sugar and releases insulin to store the "sugar." The problem is that xylitol does not offer the extra Calories of sugar and the rush of insulin only serves to remove the real sugar from the circulation. Blood sugar levels plummet resulting in weakness, disorientation, tremors, and potentially seizures.
It does not take many sticks of gum to poison a dog, especially a small dog (see below for toxic doses). Symptoms typically begin within 30 minutes and can last for more than 12 hours. Vomiting and diarrhea may also occur.
2. Hepatic Necrosis
The other reaction associated with xylitol in the canine body is actual destruction of liver tissue. How this happens remains unknown, but the doses of xylitol required to produce this effect are much higher than the hypoglycemic doses described above. Signs take longer to show up (typically 8-12 hours) and surprisingly not all dogs that experience hepatic necrosis, will have experienced hypoglycemia first. A lucky dog experiences only temporary illness but alternatively, a complete and acute liver failure can result with death following. Internal hemorrhage and inability of blood to clot is commonly involved.
What Products Contain Xylitol?
Makers of products with xylitol say their products are designed for people, including diabetes patients, who are seeking an alternative to sugar; they were never recommended for dogs and were never intended to be ingested by dogs.
The following is a list of products that contain xylitol:
- Orbit gum
- Trident gum
- Stride gum
- Ice Breakers gum
- Biotene Mouthwash
- Breath Rx
- TheraBreath toothpaste & mouthwash
- Tom's of Maine products
- Mint Asure
- FreshBreath capsules
- Smint "xylicare"
This list is not complete and pet owners must read ingredient labels (especially on sugar-free products) to determine if the product contains xylitol.
How much xylitol is dangerous?
The dose to cause hepatic necrosis is 1 gram per kilogram of body weight, about ten times more than the above dose. In the example above, the 10 lb dog would have to find an unopened package of gum and eat it for liver destruction to occur.
What are the clinical signs of xylitol poisoning?
Clinical signs of xylitol toxicity can develop in as few as 30 minutes after ingestion. Clinical signs may include one or more of the following:
* Ataxia/"Drunken walking" (uncoordinated movements)
* Coma and death if untreated
What is the treatment for xylitol toxicity in a dog?
First, if the dog ate the sugar-free gum or other food containing xylitol within the past two hours, the veterinarian will take measures to prevent the body's absorption of any additional xylitol. To prevent the dog's body from absorbing additional xylitol, the vet will usually induce vomiting in the dog and/or give the dog a charcoal-based fluid to adsorb the stomach contents.
Second, a dog with xylitol poisoning will receive supportive care to manage the effects of the xylitol. Treatment usually consists of a dextrose (sugar) intravenous drip to raise the dog's blood sugar levels and the injection of intravenous fluids for at least 24 hours.
Xylitol also affects the dog's liver, causing permanent liver damage in some dogs and possibly triggering liver failure in others. Additional treatment and monitoring is often required to help manage the affect of xylitol on the dog's liver. Liver enzyme and blood clotting tests are monitored for 2 to 3 days along with blood levels of potassium and phosphorus. Elevated blood phosphorus levels often has a poorer prognosis for the patient.
What about xylitol in cats?
So far the ASPCA Animal Poison Control Center has no reports of xylitol toxicity in cats. At this time, feline toxicity is unknown.
What about xylitol containing mouthwashes marketed for pets?
The oral health benefits of xylitol do seem to hold true for dogs if appropriately low doses of xylitol are used. A product called Aquadent® has been marketed for canine oral care, specifically for dogs that do not tolerate other methods of dental home care. This product is mixed in drinking water to provide antibacterial benefits. It comes in a 500 cc (half liter) bottle that contains a total of 2.5 grams of xylitol as well as in small packets. If one follows the dosing instructions on the bottle or packet, there should be no problems.
Trouble could occur if there are animals of different sizes drinking from the same water bowl (one should dose for the smallest animal to use the bowl to be sure overdose is not possible). A dog finding the bottle and chewing it up, drinking a substantial quantity of the undiluted product could easily be poisoned depending on the dog's size.
Animal Poison Control Center
Keep this phone number handy: (888) 426-4435
This is the number for the ASPCA Animal Poison Control Center, a 24-hour service whereby you can speak directly to a veterinary toxicology specialist. In addition to advice, you will receive a case number which your veterinarian can use for further consultation at no additional charge.
If you suspect your dog has ingested a product containing xylitol please call the Merrick Veterinary Group at 516-379-6200 immediately for further instructions.