The Dangers of Xylitol for Dogs

Imagine this — you’re enjoying a piece of sugar-free gum, totally unaware that the seemingly harmless ingredient it contains could be a silent killer for your furry family member.

Xylitol (pronounced ZIH-luh-tawl) is a common sweetener and sugar substitute in many items, ranging from sugar-free candies to baked goods to peanut butter. It’s even a common ingredient in some brands of toothpaste!

But this widespread sweetener is incredibly toxic to dogs, as it leads to a dangerous drop in their blood sugar levels. It’s important for pet parents to learn to read ingredient labels, understand the symptoms of xylitol poisoning in dogs, and know when and where to seek immediate veterinary attention if ingestion occurs.

What is Xylitol?

You’ve heard of it (and probably eaten it), but let’s break down some facts about what xylitol actually is.

• Xylitol is a sugar alcohol: a type of carbohydrate that is similar in structure to both sugar and alcohol. Despite the name, sugar alcohols don't actually contain ethanol, the type of alcohol found in alcoholic beverages.
• It’s sweet yet low in calories. Sugar alcohols such as xylitol are added to foods or products to give them a sweet flavor, without the calories and impact on insulin and blood sugar associated with sugar. Xylitol contains 40% fewer calories than sugar and its glycemic index (a measure of how quickly a food raises blood sugar) measures just 7, compared to 60-70 for sugar.
• Small amounts of xylitol are found naturally in many fruits and vegetables (such as raspberries), but it can also be commercially processed from plant fibers like birch bark and corn cobs.
• Xylitol is generally considered safe for human consumption, although excessive intake can cause digestive issues, such as gas, bloating, and diarrhea in some people.
• It helps prevent tooth decay. Unlike sugar, oral bacteria cannot metabolize xylitol. By depriving these bacteria of their energy source, xylitol helps reduce their growth and activity. This, along with several other mechanisms, makes it an effective ingredient in some oral care products, such as toothpaste, mouthwash, and dental floss.
• Xylitol is commonly found in sugar-free foods and beverages, such as gum, candies, mints, chocolate, and desserts. As mentioned above, it's also used in some medications and oral care products.
• Xylitol is highly toxic to dogs and has two potentially deadly effects — hypoglycemia and hepatic necrosis (liver damage).
• Xylitol can also be listed under different names on ingredient labels, so beware of xylitol by any of these other names:
• Birch Sugar
• Birch Sap
• Wood Sugar
• E967 (its European food additive number)
• Xylite
• Anydroxylitol
• Mes-xylitol
• Xlitol
• Xylo-pentane-1,2,3,4,5
• Sucre de bouleau (in French-speaking areas)

What Does Xylitol Do to Dogs?

Xylitol has significant effects on a dog’s blood sugar and on their liver. Before we dive into how xylitol affects dogs, let's first review what blood sugar is and how it’s regulated.

Xylitol's Effects on Blood Sugar in Dogs

Blood sugar, also known as blood glucose, is the concentration of glucose present in the blood. Glucose is a simple sugar and serves as the primary source of energy for the body's cells and tissues. The level of blood sugar is tightly regulated by the body through a complex system.

Maintaining stable blood sugar levels is crucial for overall health. When blood sugar levels are too high (hyperglycemia) or too low (hypoglycemia), health complications can arise.

When a dog eats, the carbohydrates it consumes are broken down into glucose, which enters the bloodstream. This rise in blood sugar signals the pancreas to release insulin. The insulin then travels through the bloodstream and binds to specific receptors on the surface of cells throughout the body.

This binding, much like a key fitting into a lock, triggers a series of events that open up channels within the cell membrane, allowing glucose to enter. Once inside the cells, glucose is either used immediately for energy or stored for later use.

But things don’t always work perfectly. In diabetic dogs, for example, insulin either isn't produced in sufficient amounts (not enough keys) or doesn't work effectively to unlock the cell doors for glucose (the keys are rusty and don’t always fit the locks). This imperfect processing results in glucose building up in the bloodstream, leading to high blood sugar and the various health complications and symptoms associated with diabetes.

So how does xylitol fit in? In humans, xylitol doesn’t affect blood sugar levels or cause insulin release. In dogs, however, xylitol is mistaken for glucose. It gets rapidly absorbed into the blood, and leads to a massive release of insulin.

In fact, a dog’s pancreas actually releases 3-7 times more insulin in response to xylitol than it would in response to a similar amount of actual sugar. This results in a fast (generally within 30-60 minutes) and dangerous drop in blood sugar, known as hypoglycemia, and associated symptoms of low blood sugar.

Another Side Effect: Hepatic Necrosis

Xylitol can also cause destruction of the liver — a condition known as hepatic necrosis. Why? Veterinary science doesn’t know yet.

These liver-damaging effects take longer to occur, are more likely to be seen if a larger amount of xylitol is ingested, and can range in severity from mild to complete and fatal liver failure.

Symptoms of Xylitol Toxicity in Dogs

Symptoms of xylitol toxicity due to low blood sugar may begin within 30-60 minutes of ingestion, but can also be delayed for up to 12 hours. Be on the lookout for:

• Lethargy
• Weakness
• Ataxia (lack of coordination or stumbling)
• Disorientation
• Vomiting
• Seizures
• Coma

Signs of liver failure in dogs may not be obvious until 8 to 72 hours after ingestion. Interestingly, not all dogs who develop liver failure from xylitol toxicity show signs of hypoglycemia first. Additional signs of liver failure may include:

• Depression
• Jaundice - yellowing of the skin, gums, or whites of the eyes
• Vomiting
• Bleeding disorders

The dose of xylitol that results in hypoglycemia is generally considered to be just 0.075 to 0.1 grams per kilogram of body weight, while just 0.5 grams per kilogram can result in acute hepatic necrosis. That means a small dog can be poisoned by a single stick of chewing gum.

What Happens if My Dog Eats Xylitol?

If your dog eats something containing xylitol, it’s crucial to contact your veterinarian or a pet poison hotline immediately.

Have the packaging of whatever your dog ate on hand for the vet to review. They’ll also want to know how much of the item your dog ate, how long ago ingestion occurred, and if you’ve noticed any symptoms.

Keep these numbers handy by saving them in your phone and/or taping them to your fridge:

ASPCA Poison Control: (888) 426-4435

Pet Poison Helpline: (855) 764-7661

Diagnosing Xylitol Toxicity in Dogs

There is no specific test to diagnose xylitol poisoning. Your veterinarian will take a thorough medical history and perform a nose-to-tail physical exam.

Your vet will also do bloodwork in order to evaluate your dog’s blood sugar levels and liver values. Changes in bloodwork associated with xylitol toxicity may include hypoglycemia (low blood sugar), decreased potassium, and elevated ALT, AST, ALP, and bilirubin (indicative of liver disease), among other abnormalities.

Bloodwork can help guide your veterinarian’s treatment plan, as well as provide information about your pet’s prognosis.

Treating Xylitol Toxicity in Dogs

If your dog has ingested xylitol, they need fast and aggressive veterinary care. Treatment focuses on stabilizing blood sugar levels and managing liver damage. If the ingestion occurred recently (generally less than 30 minutes) and your dog is not showing any clinical signs, then your veterinarian may try to make them vomit the gum or candy. However, treatment more commonly involves:

• Administering sugar (dextrose) through intravenous fluids to help increase and stabilize blood sugar
• Medications to protect the liver and gastrointestinal tract tract
• Additional supportive care, such as antinausea medication

Your dog will remain hospitalized for at least 12-24 hours so that they can be closely monitored. Bloodwork should also be checked again after three days to make sure there are no signs of liver damage.

Luckily, most dogs who are treated quickly and aggressively for hypoglycemia have a good prognosis. Those who develop liver injury, unfortunately, have a more guarded prognosis. Therefore, it’s extremely important to prevent your dog from eating xylitol in the first place.

Preventing Xylitol Poisoning in Dogs

Xylitol is everywhere, even in products that you may not expect. For this reason, it’s critical to thoroughly read the label before sharing any foods or products with your dog.

Remember that list of alternative names above? Be aware that while xylitol may be listed by name on an ingredient label, it might instead be listed as sugar alcohol, birch sugar, wood sugar, E967, or birch bark extract. Foods containing xylitol may also be labeled simply as “sugar-free” or “reduced sugar”.

Here are 3 simple ways to prevent xylitol poisoning before it happens:

1. Store any products containing xylitol in areas where your dog cannot access them (or choose xylitol-free alternatives).
2. Educate all members of your family about what’s safe for your dog to eat and what to avoid.
3. Finally, make sure your dog has a strong “leave it” and “drop it” command in case of accidents.

Thanks for keeping yourself informed about the dangers of xylitol for dogs!