This is a syndrome characterized by paralysis of the alimentary tract and can present as an acute gastric dilatation or as more chronic situations that are most commonly misdiagnosed as impactions. The aetiology is unknown. Grossly, the oesophagus has numerous 2-3 cm linear ulcers in the mucosa. This resulted probably as a secondary phenomenon to the oesophago-gastric paralysis and reflux of ingesta into the oesophagus. Microscopically, there are mucosal ulcers that extend into the submucosa.
Hyperkeratotic epithelium is piled up on the sides of the ulcers.
No organisms or other obvious aetiologic agents are seen. Comment Presently, the histologic diagnosis of grass disease rests on degenerative changes in ganglion cells in places such as the coeliac, mesenteric and thoracic ganglia. This section is taken from a dog with uraemia as a result of chronic renal failure. There is extensive necrosis and ulceration of the epithelium at the tip of the tongue. There is hyperaemia and subepithelial infiltration of lymphocytes and plasma cells.