Secondary peristalsis refers to the anti-peristaltic movement noted during regurgitation. Primary peristalsis is essential for secondary peristalsis to occur. Secondary peristalsis is elicited by the presence of a foreign body or food bolus. Duration of action of ultrashort-acting barbiturates is primarily dependent upon redistribution to lean body tissues. Glycerol guaiacolate produces relaxation of skeletal muscles, laryngeal and pharyngeal muscles, and the diaphragm.
Ketamine hydrochloride produces apneustic breathing and tachycardia.
Chloral hydrate produces significant sedation and respiratory depression, but poor analgesia. Tumor necrosis factor is synthesized primarily by vascular endothelial cells in response to exposure to endotoxin. Serum concentrations of tumor necrosis factor activity are highest in horses over 15 years of age. Serum tumor necrosis factor activity is greatest in horses with inflammatory disorders or strangulation obstruction. There is no apparent correlation between serum tumor necrosis factor activity and mortality.