Diagnosis and management of acute and chronic vomiting in dogs and cats (Proceedings)
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. These included:
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 unreported.
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.