Acute gastritis

True vomiting may be due to acute or chronic gastritis for which there are many causes (Table Conditions of the stomach). It is also important to remember that true vomiting may be due to non-gastric causes (). Apparent vomiting, or in reality regurgitation, may be associated with oesophageal disease and this should be carefully differentiated ().

Table Conditions of the stomach

Acute gastritis
Chronic gastritis
Idiopathic
A trophic
Hypertrophic
Eosinophilic
Gastric ulceration
Gastric neoplasia
Gastric foreign body
Gastric motility disorders
Pyloric stenosis
Gastric dilation/torsion

Acute gastritis occurs where sudden and significant inflammation of the mucosa occurs, often involving some dietary indiscretion. In particular the history may suggest access to spoiled foods, foreign bodies, grass, bones and chemicals, e.g. detergents, antifreeze, which abrade and inflame the mucosa. Although infectious agents may cause acute gastritis they rarely do so exclusively, so enteritis or other systemic symptoms would be expected. The mucosal damage created allows acid and pepsin to diffuse back onto the mucosal surface leading to inflammation, cellular infiltration and ulceration where the condition is severe or chronic. Mast cell disruption releases histamine which induces further acid production and so potentiates the damage. Afferent nerves are stimulated leading to vomiting through the vomiting centre, and distention of inflamed stomach by further food or liquid intake acts as a powerful stimulus to vomiting ().

Clinical diagnosis

Acute sudden onset of vomiting is initially associated with food or liquids but as anorexia develops so vomiting may occur at any time. Weakness, depression, dehydration, collapse and occasionally fever may be detected, although a reduced temperature once collapsed is more common. It is important to differentiate acute gastritis from gastric or intestinal obstruction, intussusception, acute pancreatitis, acute hepatitis, poisoning and specific infections.

A diagnosis is usually based on history and clinical findings. If symptomatic treatment fails, then it is usual to instigate an investigation. Such an investigation might include radiography and barium studies and blood chemistry if a secondary non-gastric cause of vomiting is suspected.

Acute gastritis: Treatment

Total gastric rest for at least 24 h prevents gastric distention and so reduces the frequency of vomiting. Gastric rest also inhibits acid and pepsin production which would further inflame the mucosa. Administration of kaolin or bismuth oral preparations when vomiting stops, acts as protectants. Antiemetics such as metaclopramide (Emequell; SmithKline Beecham Pharmaceuticals) 0.5 to 1.0mg/kg every 8h may be given as long as there is no evidence of obstruction. Rehydrate with intravenous Hartmans solution or isotonic dextrose saline. Once vomiting has stopped for at least 24 h start oral electrolyte solution (Lectade; SmithKline Beecham Pharmaceuticals) as an oral rehydrant instead of water, and if vomiting does not recur feeding bland easily-digested food in small amounts should be initiated.

 

Selections from the book: “Digestive Disease in the Dog and Cat” (1991)