Gastric Motility Disorders

Signalment

Can affect both dogs and cats.

Description

Abnormal gastric motility has been cited as a contributing factor of conditions such as gastric dilatation-volvulus and gastric outflow obstruction that has resulted from pylorospasm. Many potential causes of gastric stasis have been proposed:

• nervous inhibition due to pain or trauma
• electrolyte or acid-base imbalances
• uraemia
• hypothyroidism
• hepatic encephalopathy
• pancreatitis
• gastric ulceration and inflammation
• anticholinergic drugs and narcotic analgesics used to treat vomiting and diarrhoea
• idiopathic

Diagnosis

Diagnosis of gastric motility disorders is usually made once other causes of vomiting have been ruled out. The normal gastric emptying time of a dog is 10-12 hours. Therefore, a dog that vomits an undigested meal more than twelve hours after feeding should be strongly suspected of having a gastric motility disorder if an outflow obstruction and inflammatory disease have been excluded.

Clinical Signs

• chronic belching and vomiting
• anorexia
• weight loss
• poor body condition

Radiography

• Contrast radiography may support a diagnosis of a gastric motility disorder:
  • Half of the animal's daily caloric requirement should be fed as canned food mixed with 5% by weight of barium sulphate. Radiographs are taken every hour until the stomach is empty. This amount of food is normally emptied by the stomach in 5-8 hours. If food is still present after this time, a motility problem is suggested.
• Fluoroscopy studies may be used to assess gastric motility.

Special Diagnostic Techniques

A definitive diagnosis of gastric motility disorders requires special diagnostic techniques that are not often available. These include measurement of gastric electrical and contractile activity as well as radio-isotope studies.

Treatment

Underlying causes of vomiting should be addressed first. Drugs that promote gastric peristalsis/motility may be administered once a diagnosis of a gastric motility disorder has been reached. Several drugs have been proposed and may include:

• Cisapride (30 minutes before each meal)
  • reduces tachygastria
  • increases tone and amplitude of gastric contractions
  • relaxes the pyloric canal
  • increases contraction in the proximal small intestine
• Erythromycin
  • acts on smooth muscle motilin receptors to increase gastric contractility
• Metoclopramide
  • increases gastric peristalsis

Prognosis

Animals that respond well to medical management have a good prognosis. Those who respond poorly to medical treatment have a poor prognosis.

References

• Hall, E.J, Simpson, J.W. and Thomas, D. (2005) BSAVA Manual of Canine and Feline Gastroenterology (1st Edition) BSAVA Page 109

• Nelson, R.W. and Couto, C.G. (2009) Small Animal Internal Medicine (Fourth Edition) Mosby Elsevier Page 427