Etiology

• Although not accurately known, research has shown atrophic gastritis can occur following inoculation of the dog with its own gastric secretion. Thus, the disease is thought to be an immune response to gastric secretions.
• Atrophic gastritis has also been associated withHelicobacter pylori Helicobacter spp Gastritis: helicobacter infection in man.

Predisposing factors

• Damage to the gastric mucosal barrier is required to permit gastric secretion access to the mucosa and deeper tissues.
• This may be caused by many factors including: ingested drugs (glucocorticoids, NSAID), chemicals, foreign bodies, uremia, tumor,Helicobater sp., other forms of chronic gastritis Stomach: chronic gastritis. Dogs are not considered typical hosts ofH. pylori, but do become infected with a number of other species.

Pathophysiology

• Damage to the gastric mucosal barrier allows back flow of gastric acid and pepsin to enter the mucosa resulting in further damage and inflammation. A vicious cycle is established which maintains and develops the inflammation.
• Immune destruction of the chief and parietal cells may follow together with loss of trophic factors which can result in atrophic gastritis developing over a period of months, based on research studies.
• Vitamin B12 deficiency does not occur in dogs, cf. man; however, lack of acid may result in calcium or iron deficiency in the long term.
• Secondary malabsorption associated with loss of pepsin and acid digestion together with achlorhydria permitting small intestinal bacterial overgrowth Antibiotic-responsive diarrhea (ARD) , may lead to chronic diarrhea Diarrhea: chronic.