Post by trinitydobes on Feb 15, 2012 11:30:59 GMT -5
Awareness of xylitol toxicity in dogs still lacking
January 31, 2012, By: Phyllis DeGioia, For The VIN News Service
A variety of sugarless gums, including some in this rack at a grocery store in Wisconsin, contain the artificial sweetener xylitol, which is toxic to dogs.
After Sophie binged on approximately 60 pieces of sugarless gum, what stands out in the minds of her owners Andi Dennison and Peter Johnson isn’t the six days of intensive treatment for the yellow Labrador retriever, nor the $7,000 medical bill.
What stuns the Gaithersburg, Md., couple, is that they had no idea the artificial sweetener xylitol, commonly found in sugarless gum and other candies, is toxic to dogs.
They had never heard that xylitol (pronounced ZI-luh-tohl) can wreak havoc on a canine's blood sugar levels, resulting — in severe cases — in liver failure.
“The only people who I knew that knew xylitol was toxic were the vets and vet techs,” Dennison said.
Like Sophie’s owners, many pet owners are just discovering the dangers of xylitol. The veterinary community itself has been aware of xylitol toxicity to dogs for only a few years, and many practitioners have questions about appropriate treatment.
Members of the Veterinary Information Network (VIN), an online profession for the community and parent of the VIN News Service, regularly raise questions such as: How much xylitol is in one piece? How much xylitol remains in chewed gum? How long should a dog that’s eaten xylitol be treated? Does ingestion cause long-term health effects?
The number of products containing xylitol seems to be growing, as is the number of poisoning cases, judging from records kept by the American Society for Protection of Animals’ Animal Poison Control Center (ASPCA APPC) in Urbana, Ill.
According to ASPCA APPC Medical Director Dr. Tina Wismer, the center began in 2007 to tally cases involving xylitol. That year, the center fielded 1,764 calls. In 2011, the call volume reached 3,045, an increase of 73 percent.
Certain foods are well-known to dog owners to be toxic to their pets. Who hasn’t heard that dogs shouldn’t eat chocolate, grapes and raisins? But most, it seems, don’t realize that products containing xylitol may cause more harm.
"I'll get calls from people saying 'My Great Dane just ate two M&Ms,' but xylitol is far worse than chocolate," said Dr. Tony Johnson, a clinical assistant professor at Purdue University College of Veterinary Medicine and an emergency-medicine consultant at VIN.
“I think people don't know more about (xylitol) because whenever there is something that presents harm to animals, companies aren't necessarily shouting from the rooftops about it,” Johnson said.
Moreover, he noted, it hasn’t been that long that the veterinary medical community has known about the hazards of xylitol to dogs.
"I can remember seeing cases where we didn't know what the dog got into and now we realize what it was,” Johnson recalled. “Back then, if I heard a dog got into chewing gum, my reaction would have been 'Let him chew it.'
“I wonder what else we're going to find out is toxic in five years?” Johnson mused.
The first paper in a veterinary journal about xylitol appeared in 2004. The author of that study, published in Veterinary & Human Toxicology, predicted, "With the increased appearance of xylitol-sweetened products in the U.S., xylitol toxicosis in dogs may become more common."
By comparison, the first study to appear in a veterinary journal about problems with chocolate in dogs was published in 1981, according to results of a search on PubMed, a database-access service maintained by the U.S. Library of Medicine.
Xylitol is a natural substance derived from the bark of birch trees. It is referred to as an artificial sweetener because it is a sugar alcohol. In people, xylitol generally has no effect on plasma insulin or glucose levels, making it a popular sweetener among diabetics. The substance seems to be tolerated by most people, although it can cause diarrhea in some. Research suggests the use of xylitol instead of sugar may benefit dental health.
Dogs metabolize xylitol differently from people. In dogs, xylitol triggers a large release of insulin that causes a sudden drop in blood sugar, a condition called hypoglycemia. According to Johnson, signs of hypoglycemia include unsteadiness, depression, dilated pupils and, in severe cases, seizures. If ingested in quantity, xylitol may lead to liver failure. Signs are subtle and include lethargy, vomiting, loss of appetite and diarrhea.
According to Wismer, the toxic dose of xylitol for dogs is 75-100 mg/kg. It’s easy enough to determine the weight of an affected dog, but knowing how much xylitol the dog ate is another matter. Wismer said some manufacturers consider the level of xylitol in their products to be proprietary information and refuse to disclose it. The amount may differ not only from manufacturer to manufacturer, but from flavor to flavor.
Based on information provided by some manufacturers, Wismer has deduced that the quantity of xylitol in one piece of gum ranges from 0.9 mg to 1,000 mg. "It's a big difference," she said.
Products that list xylitol as the first ingredient tend to be the most toxic to dogs, she added.
As with most toxicants, the dose makes the poison. That explains why xylitol in doggy dental products, such as Virbac’s AquaDent, doesn’t sicken its users. Wismer said the amount of xylitol is so low that ingestion by dogs is equivalent to people eating apple seeds, which contain traces of cyanide.
The form of xylitol used in a product affects its toxicity, as well. Wismer said some xylitol used in candies and mints is in a powder that is absorbed quickly in the system, causing signs of illness in 30 minutes.
Gum is different. “You have to chew to release xylitol,” Wismer said, noting that dogs tend to swallow gum whole without chewing. "It still leaches out into the stomach but it takes longer. ... If we haven't seen any signs after eight to 12 hours of (a dog) ingesting gum, toxicity won't be an issue. That means we have a lot of time to make these dogs vomit and decrease the amount absorbed."
As for the dangers posed to dogs of eating already-chewed gum, Wismer said the more thoroughly a piece of gum has been chewed, the less sweetener it will contain.
Johnson, one of three veterinary criticalists at Purdue, said assessing the severity of a case of xylitol ingestion is tricky. “There is no assay or test to run to determine how much they got into,” he said. “I've only seen a couple of cases, and they were mildly clinical. I think people need to be aware but they don't need to freak out. It's not up there with antifreeze and rat poison. It's fairly easy to treat if you know what you're dealing with.”
Sophie, a yellow Labrador retriever, was hospitalized for the better part of a week and nearly died after she devoured nearly 60 pieces of gum containing xylitol. She recovered.
According to Johnson, typical treatment for xylitol toxicity is supportive treatment of fluids with dextrose to reduce the hypoglycemia. In severe cases, some veterinarians also may give dexamethasone, a corticosteroid, and glucagon, a hormone used to raise very low blood sugar.
Johnson pointed out that not every significant ingestion results in liver failure. When it does, no "magic bullet" exists to treat it, he said. Supportive care is given while the patient's blood chemistry is tracked.
Length of treatment depends on severity of clinical signs. Johnson said a typical case without liver involvement generally requires one to three days of treatment. He said treatment should continue until glucose levels are normal or as directed by the APCC.
As far as long-term health effects, Wismer said she hasn't seen any lingering medical issues once liver problems are successfully resolved.
Other household pet species may be affected by xylitol, as well, but the evidence is unclear.
The U.S. Food and Drug Administration Center for Veterinary Medicine has posted a caution about the dangers of xylitol ingestion in dogs and ferrets. However, Wismer said the APCC has received no reports of xylitol poisoning in ferrets.
On the contrary, “We've had several cases with ferrets who ate gum and had no problems,” Wismer said.
How about cats? Wismer said cats appear to be able to eat xylitol with no ill effect. “Some toxicity studies found that it was not a problem orally but when given by IV can cause liver failure. It depends on the quantity and method of administration,” she said.
January 31, 2012, By: Phyllis DeGioia, For The VIN News Service
A variety of sugarless gums, including some in this rack at a grocery store in Wisconsin, contain the artificial sweetener xylitol, which is toxic to dogs.
After Sophie binged on approximately 60 pieces of sugarless gum, what stands out in the minds of her owners Andi Dennison and Peter Johnson isn’t the six days of intensive treatment for the yellow Labrador retriever, nor the $7,000 medical bill.
What stuns the Gaithersburg, Md., couple, is that they had no idea the artificial sweetener xylitol, commonly found in sugarless gum and other candies, is toxic to dogs.
They had never heard that xylitol (pronounced ZI-luh-tohl) can wreak havoc on a canine's blood sugar levels, resulting — in severe cases — in liver failure.
“The only people who I knew that knew xylitol was toxic were the vets and vet techs,” Dennison said.
Like Sophie’s owners, many pet owners are just discovering the dangers of xylitol. The veterinary community itself has been aware of xylitol toxicity to dogs for only a few years, and many practitioners have questions about appropriate treatment.
Members of the Veterinary Information Network (VIN), an online profession for the community and parent of the VIN News Service, regularly raise questions such as: How much xylitol is in one piece? How much xylitol remains in chewed gum? How long should a dog that’s eaten xylitol be treated? Does ingestion cause long-term health effects?
The number of products containing xylitol seems to be growing, as is the number of poisoning cases, judging from records kept by the American Society for Protection of Animals’ Animal Poison Control Center (ASPCA APPC) in Urbana, Ill.
According to ASPCA APPC Medical Director Dr. Tina Wismer, the center began in 2007 to tally cases involving xylitol. That year, the center fielded 1,764 calls. In 2011, the call volume reached 3,045, an increase of 73 percent.
Certain foods are well-known to dog owners to be toxic to their pets. Who hasn’t heard that dogs shouldn’t eat chocolate, grapes and raisins? But most, it seems, don’t realize that products containing xylitol may cause more harm.
"I'll get calls from people saying 'My Great Dane just ate two M&Ms,' but xylitol is far worse than chocolate," said Dr. Tony Johnson, a clinical assistant professor at Purdue University College of Veterinary Medicine and an emergency-medicine consultant at VIN.
“I think people don't know more about (xylitol) because whenever there is something that presents harm to animals, companies aren't necessarily shouting from the rooftops about it,” Johnson said.
Moreover, he noted, it hasn’t been that long that the veterinary medical community has known about the hazards of xylitol to dogs.
"I can remember seeing cases where we didn't know what the dog got into and now we realize what it was,” Johnson recalled. “Back then, if I heard a dog got into chewing gum, my reaction would have been 'Let him chew it.'
“I wonder what else we're going to find out is toxic in five years?” Johnson mused.
The first paper in a veterinary journal about xylitol appeared in 2004. The author of that study, published in Veterinary & Human Toxicology, predicted, "With the increased appearance of xylitol-sweetened products in the U.S., xylitol toxicosis in dogs may become more common."
By comparison, the first study to appear in a veterinary journal about problems with chocolate in dogs was published in 1981, according to results of a search on PubMed, a database-access service maintained by the U.S. Library of Medicine.
Xylitol is a natural substance derived from the bark of birch trees. It is referred to as an artificial sweetener because it is a sugar alcohol. In people, xylitol generally has no effect on plasma insulin or glucose levels, making it a popular sweetener among diabetics. The substance seems to be tolerated by most people, although it can cause diarrhea in some. Research suggests the use of xylitol instead of sugar may benefit dental health.
Dogs metabolize xylitol differently from people. In dogs, xylitol triggers a large release of insulin that causes a sudden drop in blood sugar, a condition called hypoglycemia. According to Johnson, signs of hypoglycemia include unsteadiness, depression, dilated pupils and, in severe cases, seizures. If ingested in quantity, xylitol may lead to liver failure. Signs are subtle and include lethargy, vomiting, loss of appetite and diarrhea.
According to Wismer, the toxic dose of xylitol for dogs is 75-100 mg/kg. It’s easy enough to determine the weight of an affected dog, but knowing how much xylitol the dog ate is another matter. Wismer said some manufacturers consider the level of xylitol in their products to be proprietary information and refuse to disclose it. The amount may differ not only from manufacturer to manufacturer, but from flavor to flavor.
Based on information provided by some manufacturers, Wismer has deduced that the quantity of xylitol in one piece of gum ranges from 0.9 mg to 1,000 mg. "It's a big difference," she said.
Products that list xylitol as the first ingredient tend to be the most toxic to dogs, she added.
As with most toxicants, the dose makes the poison. That explains why xylitol in doggy dental products, such as Virbac’s AquaDent, doesn’t sicken its users. Wismer said the amount of xylitol is so low that ingestion by dogs is equivalent to people eating apple seeds, which contain traces of cyanide.
The form of xylitol used in a product affects its toxicity, as well. Wismer said some xylitol used in candies and mints is in a powder that is absorbed quickly in the system, causing signs of illness in 30 minutes.
Gum is different. “You have to chew to release xylitol,” Wismer said, noting that dogs tend to swallow gum whole without chewing. "It still leaches out into the stomach but it takes longer. ... If we haven't seen any signs after eight to 12 hours of (a dog) ingesting gum, toxicity won't be an issue. That means we have a lot of time to make these dogs vomit and decrease the amount absorbed."
As for the dangers posed to dogs of eating already-chewed gum, Wismer said the more thoroughly a piece of gum has been chewed, the less sweetener it will contain.
Johnson, one of three veterinary criticalists at Purdue, said assessing the severity of a case of xylitol ingestion is tricky. “There is no assay or test to run to determine how much they got into,” he said. “I've only seen a couple of cases, and they were mildly clinical. I think people need to be aware but they don't need to freak out. It's not up there with antifreeze and rat poison. It's fairly easy to treat if you know what you're dealing with.”
Sophie, a yellow Labrador retriever, was hospitalized for the better part of a week and nearly died after she devoured nearly 60 pieces of gum containing xylitol. She recovered.
According to Johnson, typical treatment for xylitol toxicity is supportive treatment of fluids with dextrose to reduce the hypoglycemia. In severe cases, some veterinarians also may give dexamethasone, a corticosteroid, and glucagon, a hormone used to raise very low blood sugar.
Johnson pointed out that not every significant ingestion results in liver failure. When it does, no "magic bullet" exists to treat it, he said. Supportive care is given while the patient's blood chemistry is tracked.
Length of treatment depends on severity of clinical signs. Johnson said a typical case without liver involvement generally requires one to three days of treatment. He said treatment should continue until glucose levels are normal or as directed by the APCC.
As far as long-term health effects, Wismer said she hasn't seen any lingering medical issues once liver problems are successfully resolved.
Other household pet species may be affected by xylitol, as well, but the evidence is unclear.
The U.S. Food and Drug Administration Center for Veterinary Medicine has posted a caution about the dangers of xylitol ingestion in dogs and ferrets. However, Wismer said the APCC has received no reports of xylitol poisoning in ferrets.
On the contrary, “We've had several cases with ferrets who ate gum and had no problems,” Wismer said.
How about cats? Wismer said cats appear to be able to eat xylitol with no ill effect. “Some toxicity studies found that it was not a problem orally but when given by IV can cause liver failure. It depends on the quantity and method of administration,” she said.