Equine inflammatory response to abdominal surgery in the absence of gastrointestinal disease

To investigate the, equine inflammatory response to ventral midline celiotomy in the absence of gastrointestinal disease in horses of varying body condition scores primarily using serial measurements of serum amyloid A (SAA).

Experimental clinical study.

University teaching hospital.

Ten adult light breed horses free of any clinical disease, 5 with body condition score (BCS) 3-4/9 and 5 with BCS 7-8/9.

Horses had a ventral midline celiotomy performed under general anesthesia, including manual decompression of the small intestine. SAA, semiquantitative fibrinogen, plasma lactate, and WBC count were measured in the blood preoperatively and at 12, 24, 48, 72, 120, and 168 hours postoperatively. Complete serum biochemistry was performed preoperatively and 24 and 72 hours postoperatively. Serial abdominocentesis was also performed with peritoneal fluid analysis of SAA, total protein, lactate, WBC count, and cytology.

Significant (P < 0.05) increases in serum SAA were noted at 12, 24, and 48 hours postoperatively (124.6 ± 68.6, 390.8 ± 209.0, 568.6 ± 197.7 μg/mL), and most horses had values approaching normal at 168 hours postoperatively (174.4 ± 307.7 μg/mL). Other values such as fibrinogen also increased in response to surgery but did not return to normal within the measured time points. Horses with high BCS did not have significantly different serum SAA compared to horses with low BCS. Peritoneal fluid SAA did not increase significantly at 12 hours postoperatively.

The information from this study can be used to help determine the effect of anesthesia and surgical intestinal manipulation resulting in increased SAA when a comparison to clinical or experimental cases is needed.