Xylitol and Dogs: What You Need to Know

What is Xylitol?

Xylitol is a sugar-derived carbohydrate found in many low-calorie sweeteners and human-grade food products. Since it raises the level of blood sugar, or glucose, by 9-10 times less than pure sugar, xylitol is considered a healthier alternative. Xylitol not only looks and tastes like raw sugar, but is especially helpful for those dealing with medical conditions that necessitate the use of a sugar substitute, such as diabetes or dental decay.

Xylitol and Dogs: The Harmful Effects

In both humans and dogs, levels of blood sugar are controlled by insulin. Upon consuming sugar, glucose levels rise, triggering the release of insulin from the pancreas to the bloodstream. Here, insulin initiates a vital sugar-to-energy transformation, where complex carbohydrates are broken down and simplified into glucose. Unlike bulky sugar molecules, glucose is small enough to efficiently enter cells. To facilitate, as well as expedite this process, insulin binds to cells and initiates the absorption of sugar from the bloodstream.

One important distinction between humans and dogs is the consumption of xylitol. In humans, xylitol consumption does not trigger the release of insulin, a hormone which helps to remove sugar from the bloodstream. This is because the body recognizes the chemical structure of xylitol as a sugar alcohol, which cannot be digested. Thus, it travels directly to the GI tract for later excretion. In dogs, xylitol has the polar opposite effect. Upon consumption, xylitol is directly absorbed into the bloodstream. This triggers an excessive release of insulin, resulting in the removal of dangerous amounts of sugar from the bloodstream, or canine hypoglycemia. Within an hour or less, hypoglycemic symptoms can become noticeable. Because this process can happen so fast, xylitol is not only toxic to dogs, but potentially fatal as well.

Xylitol Poisoning Dogs: Symptoms to Look Out For

Symptoms of xylitol ingestion are analogous to those of a human consuming poison, such as trembling and vomiting. Because xylitol results in a profoundly reduced level of blood sugar, common symptoms also include those associated with extreme canine lethargy, such as low energy, weakness, and even unconsciousness. These are the most common symptoms:

  • Vomiting: Whether your dog consumes xylitol, or any other poison, canine vomiting is generally the first symptom. Take your dog to the veterinarian as soon as possible before additional symptoms arise. Upon arrival, be prepared to discuss your dog’s relevant health history, such as recent foods ingested and events leading up to the vomiting. To aid with diagnosis, give your veterinarian more information about the vomit – color, consistency, amount, and duration.
  • Fatigue: If your dog suddenly appears weak or lethargic under otherwise normal circumstances, hypoglycemia may be in an early stage of development. Examples of hypoglycemia-induced fatigue include difficulty walking, jumping, running, or even eating and drinking. Any basic physical action will look and seem laborious.
  • Trembling: If trembling, shaking, or shivering suddenly occurs in a seemingly ordinary situation, your dog may be suffering from extreme levels of low blood sugar. Before assuming hypoglycemia, consider whether or not fear, stress, or abnormal weather conditions contributed to the abrupt onset of canine trembling.
  • Seizures: In any case of a dog seizure, immediately call your veterinarian and request emergency in-home instructions. Once the seizing stops, take your dog in for immediate treatment.
  • Fainting: Fainting, or collapse, is a sign of more advanced hypoglycemia. The body is beginning to shut down due to extremely low energy levels. Be aware as loss of consciousness may follow.  

The majority of the above symptoms take place between 30 minutes to 12 hours after ingestion. Symptom severity is proportional, depending on the amount of xylitol to body weight. According to recent reports, hypoglycemic symptoms can be induced from 0.05 grams of xylitol to one pound of weight. Comparatively, a single stick of chewing gum may contain between 6 to 8 times more xylitol.

Xylitol and Dogs: Four Questions

Helping your veterinarian determine the proper diagnosis depends on the answers to these four questions.

1) What was the concentration of xylitol in the food?

2) How much did the dog eat?

3) When did the dog first show symptoms?

4) How much time passed before action was taken?

How is Xylitol Poisoning Diagnosed?

Xylitol poisoning is diagnosed by evaluating the presence of external behavioral symptoms, in conjunction with internal vital and chemical signs.

Vital Signs

  • Blood Pressure: This is measured through a blood pressure monitor, in which a sensor cuff is placed around the tail or one of the limbs. In dogs, as well as cats, normal blood pressure is between 120-130 mmHG. Low blood pressure may be an indicator of hypoglycemia.
  • Heart Rate: This is most accurately measured with a stethoscope, but can also be measured at home by placing your hand over your dog’s heart or inside top of the hind leg. A normal resting heart rate varies depending on size, with 60-100 bpm in large dogs and 100-140 bpm in small dogs. Hypoglycemia is associated with high heart rates.
  • Respiration: Normal respiration is defined as 10 to 35 breaths per minute. To quickly measure, count your dog’s chest movements for 15 seconds and multiply by 4. Faster breathing, or shortness of breath, is generally associated with low blood pressure and an increased heart rate.

Chemical Signs

  • Chemistry Profile: This test measures a wide number of chemicals and enzymes. It functions as an overall indicator of organ health.
  • Complete Blood Count (CBC): This blood test measures red blood cells, white blood cells, platelets, and hemoglobin. Hypoglycemia results in a low red blood cell count due to loss of electrolytes.
  • Urinalysis: This is a test that collects urine either by Cystocentesis, Catherization, or Mid-Stream Free-Flow. Ideally, your dog will be able to provide a voluntary urine sample so as to avoid invasive alternatives. The veterinarian will use the urine sample to check for the presence of glucose. Normal urine should not contain any amount of glucose, while abnormal, high-glucose urine can serve as a strong indicator of hypoglycemia.


Advanced forms of hypoglycemia-induced xylitol poisoning are typically treated with dextrose, a form of glucose which is directly infused through the veins. Prior to discharge, measurement of vital signs and chemical testing may be repeated. Once stabilized, continue to closely monitor your dog’s behavior at home.

Xylitol and Prevention

Positive Xylitol Consumption

In the event that your dog has already consumed xylitol, there are two steps that you can take in order to prevent symptoms from escalating as quickly.

Liquid Sugar

If you know your dog consumed xylitol, or is showing clear signs of hypoglycemia, quickly locate a high sugar liquid. Examples include corn