Passive regurgitation during anesthesia is described as fluid draining from the mouth or nose without retching; it is most common in head-down positions and in which animals?

Passive regurgitation during anesthesia is described as fluid draining from the mouth or nose without retching; it is most common in head-down positions and in which animals?

• A. Ruminants
• B. Cats
• C. Dogs
• D. Pigs

Answer: (A)

Passive regurgitation occurs when fluids come out of the mouth or nose without the animal retching, usually because airway reflexes are suppressed during anesthesia and gravity helps material move up the esophagus. It is most common in head-down positions in ruminants because their forestomach contents, especially rumen fluid, can readily be regurgitated into the esophagus and up toward the mouth when muscle tone and protective reflexes are diminished under anesthesia. Regurgitation of rumen contents is a normal part of rumination, and in this anesthetized state the swallowing and gag reflexes are blunted, allowing these fluids to escape without the retching that accompanies vomiting. In dogs and cats, regurgitation under anesthesia occurs less frequently and is usually related to vomiting or reflux rather than passive regurgitation of rumen contents. Pigs can regurgitate as well, but the strongest predisposition is still seen in ruminants due to their unique stomach anatomy and rumination physiology.

Passive regurgitation occurs when fluids come out of the mouth or nose without the animal retching, usually because airway reflexes are suppressed during anesthesia and gravity helps material move up the esophagus. It is most common in head-down positions in ruminants because their forestomach contents, especially rumen fluid, can readily be regurgitated into the esophagus and up toward the mouth when muscle tone and protective reflexes are diminished under anesthesia. Regurgitation of rumen contents is a normal part of rumination, and in this anesthetized state the swallowing and gag reflexes are blunted, allowing these fluids to escape without the retching that accompanies vomiting. In dogs and cats, regurgitation under anesthesia occurs less frequently and is usually related to vomiting or reflux rather than passive regurgitation of rumen contents. Pigs can regurgitate as well, but the strongest predisposition is still seen in ruminants due to their unique stomach anatomy and rumination physiology.