Abstract
Subacute ruminal acidosis (SARA) is an important disorder in producing animals characterized by prolonged periods of low ruminal pH with deleterious effects on animal’s health and productivity. SARA was studied usually experimentally due to its subclinical nonspecific presentation. We present here a field outbreak of SARA in feedlot Barki sheep and the related ruminal pathological changes. Rumens of six feedlot sheep fed on high-grain fiber- deficient diets were examined for the pH of their contents as well as any abnormalities in their morphology and tissues. The results revealed that the ruminal juice of affected animals was acidic. Grossly, the ruminal mucosa was grey, hyperemic and severely thickened with multiple areas of epithelial detachment. Histopathologically, the common findings were epithelial desquamation, hydropic degeneration and ulcer formation. In addition, submuscular venular thrombosis and multifocal lesion with eosinophilic granular proteinaceous material mixed with variable numbers of inflammatory cells were noticed. This is, according to the best of the authors’ knowledge, the first example of a non-experimental field SARA outbreak in feedlot sheep and its ruminal gross and histopathological picture.