Determining factors and interspecific modeling for serum amyloid a concentrations in working horses, donkeys, and mules.

Serum amyloid A (SAA) is an acute phase protein and α-globulin that is produced in the liver in response to inflammatory cytokines. Considered a major acute phase protein in most domestic species, its concentrations rapidly decrease after resolution of inflammation, making SAA measurement a useful tool for monitoring the course of inflammation in an individual animal. The objective of this study was to compare SAA values in working equids including mules, donkeys and horses as well as values for different diseases at various times of the year. Samples were collected from 77 equids; 13 mules, 17 donkeys and 47 horses from sick or injured animals who presented to the clinic. Twenty-eight disease clinical diagnoses were compared with most cases being acute colitis. A highly significant differences between species was found when comparing SAA concentrations of mules to horses (P < .001) using Dunn comparison pairwise test. A difference (P < .05) was found between donkeys and horses, but not donkeys to mules (P > .05). The study suggests that SAA can be a helpful tool for disease diagnosis in mules and donkeys and suggests that the inflammatory response of mules maybe less than that of horses and donkeys but future studies evaluating SAA in healthy mules compared to diseased should be conducted.