Vomiting is among the most common reasons that dogs and cats are presented for evaluation. Because there are a multitude of
causes of vomiting, ranging from simple to complex, this can be a challenging problem for clinicians to accurately diagnose
and manage. The problem also causes significant concern for pet owners, especially when there is an onset of frequent severe
vomiting or when the occurrence becomes more chronic and intermittent without adequate control. However, by following a systematic
approach beginning with an accurate history, a thorough physical exam, and appropriate baseline testing (Stage 1), then performing
tests more specific for certain conditions or organ systems (e.g., bile acids assay, leptospirosis serology, ACTH stimulation,
ultrasonography) (Stage 2), and finally where indicated performing advanced procedures for more thorough examination and biopsy
or definitive therapy (endoscopy, exploratory laparotomy), most cases can be diagnosed successfully and managed judiciously.
Vomiting does not constitute a diagnosis in itself. It is emphasized that vomiting is simply a clinical sign of any of a number
of disorders that can involve any organ system in the body. In fact, one diagnostic registry service listed over 400 potential
causes of vomiting in dogs! These notes summarize diagnostic approach and various treatment options for managing dogs and
cats with vomiting.
Vomiting refers to a forceful ejection of gastric and occasionally proximal small intestinal contents through the mouth. The
vomiting act involves three stages: nausea, retching, and vomiting. Serious consequences of vomiting include volume and electrolyte
depletion, acid-base imbalance, and aspiration pneumonia.
It is essential that the clinician make a clear differentiation between regurgitation and vomiting at the outset. Regurgitation
is defined as passive, retrograde movement of ingested material, usually before it has reached the stomach. Failure to recognize
the difference between regurgitation and vomiting often leads to misdiagnosis. Regurgitation may occur immediately after uptake
of food or fluids or may be delayed for several hours or more.
A detailed, accurate history is essential
One of the most important early considerations is to determine if any toxins may have been ingested, since some compounds
can cause life threatening sequelae. The earlier a toxicity is identified, the greater the chance for successful management.
Currently, xylitol toxicity is being recognized more frequently, and sago palm plants, which can cause severe hepatotoxicity
in dogs and cats, are found in more homes and yards than in previous years. Cocoa mulch toxicity (theobromine) is also occasionally
seen. Many animals that have ingested toxins are presented with vomiting as a prominent sign. Key summary points about these
toxins are listed here.
Three case examples of important toxins that can cause vomiting as well as severe consequences including death **(accurate
history obtained early is extremely important)
Xylitol is a sugar alcohol used as a sweetener in many products, including sugar-free gum and mints, nicotine gum, chewable
vitamins, oral-care products, and baked goods. It can be purchased in a granulated form for baking and as a sweetener for
cereals and beverages. It has two-thirds the calories of sugars. It is being used more frequently in the U.S. in recent years,
and many more toxicity events in animals have occurred concurrently. Xylitol is safe in people but not dogs, where adverse
reactions can range from hypoglycemia to acute hepatic necrosis and even liver failure with coagulopathy.
Xylitol has been shown to have some attractive properties in humans, besides a lower calorie count. It has been shown to inhibit
the growth of certain bacteria, which makes it useful in preventing bacterial otitis media in children. It also has anticarcinogenic
properties because it prevents oral bacteria from producing the acids that damage tooth surfaces. This is why xylitol has
seen increased use in sugar-free gum, toothpaste, and other oral care products.
A report from the ASPCA Animal Poison Control Center published in JAVMA in 2006 discussed 8 cases of xylitol toxicity in dogs.
1. A 4 year old Welsh springer spaniel that ingested 4 large chocolate-frosted muffins that contained xylitol
2. A 3 year old standard poodle: 5 or 6 cookies
3. A 5 year old Scottish terrier: 30 pieces of gum
4. A 6 year old Labrador retriever mix: 450 g of xylitol powder
5. A 7 year old miniature dachshund: 100 pieces of gum
6. A 4 year old Australian shepherd: 12 cupcakes
7. A 8 year old Labrador retriever: 140 g of xylitol powder
8. A 6 year old Dalmatian: 8 muffins
5/8 of these dogs were euthanized or died because of liver failure!
We can help our clients by educating them about the dangers of this popular sweetener product for humans! There were no reported
cases to the poison control center in 2002-03, but the number increased to 150 reports in 2007-08. Many diagnosed cases go
Oral xylitol has a wide margin of safety in most species, BUT NOT DOGS.
Mice: Oral LD50 >20g/kg
Humans: >130 g/day will cause diarrhea but no other abnormalities
Dogs: >0.1 g/kg can cause hypoglycemia (vomiting is usually the first sign and hypoglycemia can develop in 30-60 minutes).
But in some cases of xylitol gum ingestion, hypoglycemia may be delayed for up to 12 hours. Some dogs develop elevated liver
enzymes by 12-24 hours after xylitol ingestion. Liver failure can develop even if hypoglycemia was not seen. The JAVMA report
stated that the lowest estimated dose associated with liver failure was 0.5 g/kg.
Recommendation from Dr. Eric Dunayer of the ASPCA Animal Poison Control Center:
To calculate estimated dose ingested, the following guidelines can be used:
- If xylitol is the first sugar alcohol in the ingredient list, then the dose should be based on the total amount of sugar
alcohols per piece even though this will result in an overestimation of the xylitol dose.
- If xylitol is not the first listed sugar alcohol, estimate 0.3 g of xylitol per piece of gum
- For powdered xylitol and home baked goods, 1 cup of xylitol weighs approximately 190 g.
Management of xylitol ingestion
- Induce emesis only if the animal is asymptomatic (remember that the onset of signs can be rapid)
- Activated charcoal is NOT likely to be beneficial
- Ingestion of 0.1-0.5 g/kg xylitol: Hospitalize and obtain baseline blood glucose, potassium, phosphorus, liver enzymes,
total bilirubin levels, and coag tests. Monitor glucose q 1-2 hrs over the next 12-24 hrs. Monitor the other tests every 24
hrs for 3 days.
- If hypoglycemia develops: Administer 1-2 ml/kg 25% dextrose bolus followed by IV fluids containing 2.5-5% dextrose to maintain
BG in normal range. Supplement and monitor potassium.
- For ingestion of amounts > 0.5 g/kg - - - start dextrose therapy right away, even if hypoglycemia is not yet evident. Hepatic
supportive therapy may be beneficial: (SAMe, milk thistle). The combination product Denamarin (SAMe plus silybin in a phosphatidylcholine
complex) from Nutramax provides accurate dosing. If a coagulopathy develops, plasma or blood or both may be indicated.