title: Effect of antimicrobial-containing semen extender on risk of dissemination of contagious equine metritis.
abstract: OBJECTIVE
  To determine the impact of antimicrobial-containing semen extender on the growth of Taylorella equigenitalis in semen culture-positive for contagious equine metritis (CEM) and the development of CEM after artificial insemination with CEM-positive semen extended with antimicrobial-containing semen extender.
  
  
  METHODS
  Prospective study.
  
  
  METHODS
  21 mature mares free of CEM, 1 mature stallion experimentally infected with CEM, and semen from a stallion naturally infected with CEM.
  
  
  METHODS
  CEM-positive semen was incubated in semen extender with and without antimicrobials (amikacin [final concentration, 1 g/L] and penicillin G potassium [0.63 g/L]) followed by determination of the number of colony-forming units of T equigenitalis. Mares were inseminated with raw, extended, or cryopreserved semen culture-positive for T equigenitalis and observed for clinical signs of CEM. Samples for bacterial culture were obtained from the uterus, clitoral sinuses, and clitoral fossa of mares 7, 14, and 21 days after artificial insemination.
  
  
  RESULTS
  Antimicrobial-containing semen extender significantly reduced the number of colony-forming units of T equigenitalis in CEM-positive semen. Artificial insemination with raw CEM-positive semen resulted in clinical signs of CEM, whereas artificial insemination with extended or cryopreserved CEM-positive semen did not result in clinical signs of CEM.
  
  
  CONCLUSIONS
  Antimicrobial-containing semen extender significantly reduced the risk of dissemination of CEM. The inclusion of amikacin (1 g/L) and penicillin G potassium (0.63 g/L) in extended semen reduced the transmission of CEM from stallions to mares during artificial insemination, which may result in altered dissemination of the disease.
authors.affiliation: Gluck Equine Research Center, Department of Veterinary Science, College of Agriculture, University of Kentucky, Lexington, 40546, USA.
authors.forename: Claudia
authors.initials: C
authors.lastname: Klein
authors.forename: James M
authors.initials: JM
authors.lastname: Donahue
authors.forename: Steve F
authors.initials: SF
authors.lastname: Sells
authors.forename: Edward L
authors.initials: EL
authors.lastname: Squires
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Timoney
authors.forename: Mats H T
authors.initials: MH
authors.lastname: Troedsson
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D004269:DNA, Bacterial; D005260:Female; D005836:Genitalia, Female / Q000382:microbiology; D016905:Gram-Negative Bacterial Infections / Q000517:prevention & control / Q000635:transmission / Q000662:veterinary*; D006734:Horse Diseases / Q000517:prevention & control*; D006736:Horses; D007315:Insemination, Artificial / Q000009:adverse effects / Q000662:veterinary*; D008297:Male; D012662:Semen Preservation / Q000379:methods / Q000662:veterinary*; D020625:Taylorella equigenitalis / Q000302:isolation & purification*
chemical_list: D000900:Anti-Bacterial Agents; D004269:DNA, Bacterial