Duodenojejunal mesenteric rents: Survival and complications after surgical correction in 38 broodmares (2006-2014).

OBJECTIVES: To describe short-term and long-term survival of horses with duodenojejunal mesenteric rents, and to examine the association of selected preoperative, intraoperative, and postoperative factors with survival or colic after discharge, in horses with duodenojejunal mesenteric rents. STUDY DESIGN: Retrospective case series. ANIMALS: Horses undergoing surgery for correction of small intestinal lesions secondary to duodenojejunal mesenteric rents (n = 38). METHODS: Medical records (2006-2014) of horses admitted to a referral hospital in Kentucky were reviewed. Data for preoperative and intraoperative findings, postoperative complications, and short-term survival to discharge were recorded Long-term (>12 months) survival was determined by follow-up telephone query. Association of factors with survival and colic after discharge was determined using logistic regression. RESULTS: All 38 horses were Thoroughbred broodmares. Short-term survival was 76% overall and 88% among horses that recovered from general anesthesia. Long-term survival was 74% overall and 97% for mares that survived to discharge. All long-term survivors and 85% of mares that recovered from general anesthesia returned to use for breeding. The odds of survival were significantly higher for horses ≤10 years of age (OR = 6.2; 95% CI, 1.1-34.4). Failure to close the rent was associated with increased odds of colic after discharge, but had no effect on survival. CONCLUSION: Short-term and long-term survival was high relative to prior reports and mares surviving to discharge following mesenteric rent surgery had an excellent prognosis for long-term survival. Based on our data, closure of rents is recommended to prevent recurrence of colic, but may be unnecessary for survival.

Bone gentamicin concentration after intra-articular injection or regional intravenous perfusion in the horse.

OBJECTIVE: To compare intra-articular (IA) and bone gentamicin concentrations achieved after intra-articular administration or regional intravenous perfusion (RIP). STUDY DESIGN: Experimental study. ANIMALS: Twelve healthy adult horses. METHODS: Horses were assigned to 2 treatment groups (n = 6/group): Group 1, 1 g gentamicin administered simultaneously in both left and right metacarpophalangeal joints and group 2, 1 g gentamicin administered simultaneously in both left and right lateral palmar veins. Serum, synovial fluid, and bone biopsy specimens were collected. Gentamicin concentrations were determined by fluorescence polarization immunoassay. Bone, synovial fluid, and serum gentamicin concentrations were compared over time and between groups using 2-way ANOVA. Significance of all tests were evaluated at P <.05. RESULTS: IA metacarpophalangeal joint administration resulted in higher concentration of gentamicin in synovial fluid than RIP administration. Synovial fluid concentration remained above minimum inhibitory concentration (MIC) for common pathogens for over 24 hours with IA and RIP administration. Bone gentamicin concentration remained above MIC for 8 hours with both methods; there was no significant difference in gentamicin concentration in bone with either method. Neither IA nor RIP administration had a significant effect on serum concentration of gentamicin. CONCLUSIONS: In normal horses, there is no difference in bone gentamicin concentration obtained with IA or RIP administration. CLINICAL RELEVANCE: Based on MIC for common equine pathogens, administration of gentamicin intra-articularly or by regional intravenous perfusion should be useful for treatment of osteomyelitis.