• Gastric Pathology in Horses:
• The equine stomach is relatively small ($8 - 15\text{ L}$) with an exceptionally tight cardiac sphincter that anatomically prevents vomiting or eructation.
• Severe primary gastric impaction or secondary fluid accumulation due to proximal small intestinal ileus causes acute gastric dilation.
• When intraluminal pressure exceeds tissue tensile strength:
• Rupture of the stomach occurs along the greater curvature.
• Leakage of fermenting gastric contents into the peritoneal cavity causes catastrophic septic peritonitis, cardiovascular collapse, and sudden death from peracute endogenous toxemic shock.
• nalysis:
• (Rupture of the stomach): Correct.

Correct option: (1) Rupture of the stomach.