Chapter 131 Vomiting and Regurgitation
DIFFERENTIATION OF VOMITING AND REGURGITATION
Before formulating a diagnostic and therapeutic plan, it is important to define the patient’s clinical problem. Most importantly, vomiting and regurgitation must be distinguished; pet owners may not differentiate between the two problems, but the diagnostic investigations and treatment options will differ significantly. Occasionally pet owners will describe the harsh coughing and retching of canine infectious tracheobronchitis as vomiting. In most cases the problem can be defined accurately after taking a thorough history. Historic findings likely to assist in the differentiation between vomiting and regurgitation are presented in Table 131-1. Premonitory signs, active abdominal contractions, and bile are the characteristics that are most useful for making a diagnosis in vomiting animals and that are uncommonly seen in regurgitating patients. However, regurgitating animals may stretch and arch their necks, mimicking abdominal contractions, and the response to pain from an inflamed or ulcerated esophagus may resemble the classic signs of nausea.
Table 131-1 Comparison of the Key Features of Vomiting and Regurgitation
| Vomiting | Regurgitation |
|---|---|
| Premonitory symptoms (nausea) often seen (hypersalivation, depression, discomfort) | No premonitory symptoms |
| Active abdominal contractions | Passive ejection of food |
| May occur at any time | Typically occurs shortly after ingestion of food |
| Digested food | Undigested food, may conform to the cylindric shape of the esophagus |
| Bile may be present | No bile |
REGURGITATION
Differential Diagnoses
Regurgitation is associated with esophageal or pharyngeal disease. It is more common in dogs than in cats. In most cases the problem is localized to the esophagus or pharynx, but it is sometimes a manifestation of systemic disease. Common differential diagnoses are provided in Box 131-1. Idiopathic megaesophagus is the most common cause of regurgitation in the adult dog, and most middle-aged to older patients with uncomplicated regurgitation prove to have this disease.1 However, it should be noted that focal myasthenia gravis is a significant cause of megaesophagus in the absence of other neurologic signs.
Box 131-1 Important Differential Diagnoses for Regurgitation
