Which of the following is NOT listed as an etiology of secondary free gas bloat?

• A. Esophageal dysfunction
• B. Reticuloruminal problem
• C. Positional
• D. Abomasal ulcer

Answer: (D)

The concept here is what kinds of problems can cause secondary free gas bloat by blocking eructation or rumen outflow. Secondary free gas bloat happens when gas is produced in the rumen but cannot be expelled properly, so it accumulates.

Esophageal dysfunction directly blocks the passage of gas from the rumen up the esophagus, preventing eructation. Reticuloruminal problems disrupt motility or outflow, again hindering gas release. Positional factors can alter anatomy or pressure around the rumen/esophagus and impede eructation, leading to gas buildup.

Abomasal ulcer, on the other hand, is a disease of the abomasum itself and does not typically interfere with ruminal eructation or outflow. It causes signs like pain, reduced intake, or melena, but it does not function as an etiology for secondary free gas bloat.