Objective—To compare the effect of semen extender
and seminal plasma on postthaw motility and filtration
through a glass wool-Sephadex (GWS) filter for frozen
Sample Population—7 stallions from which we collected
≥ 3 ejaculates/stallion.
Procedure—4 experiments were conducted to evaluate
postthaw quality of frozen stallion semen.
Kenney extender was compared with glucose-EDTA
extender by use of various dilution rates that resulted
in differing concentrations of seminal plasma. Stallions
known to produce semen with poor postthaw quality
were used to investigate whether a particular extender
or dilution rate could improve ability of such semen
to survive freeze-thaw procedures.
Results—Use of Kenney extender as the centrifugation
extender significantly improved postthaw motility
and GWS filtration, compared with glucose-EDTA.
Extending semen at a dilution of 1:3 was significantly
better than 1:1 for both motility and GWS filtration. In
addition, including seminal plasma at a concentration
of 5% in the cryopreserved semen resulted in significantly
higher yield of spermatozoa after GWS filtration,
compared with complete removal of SP or use of
seminal plasma at 25%. Lastly, semen with poor
postthaw quality had significantly improved postthaw
quality in regard to motility and GWS filtration when
semen was frozen with seminal plasma at a concentration
of 5%, compared with semen frozen with
seminal plasma at a concentration of 25%.
Conclusion and Clinical Relevance—Use of Kenney
extender at a high dilution (≥ 1:3) immediately after collection
of semen can improve postthaw quality of
frozen stallion semen. (Am J Vet Res
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.
Animals—21 mature mares free of CEM, 1 mature stallion experimentally infected with CEM, and semen from a stallion naturally infected with CEM.
Procedures—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 and Clinical Relevance—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.
Case Description—A 19-year-old Thoroughbred mare was evaluated at 265 days of gestation with a markedly distended abdomen and edema of the ventral portion of the abdomen.
Clinical Findings—The uterus was distended over the pelvic rim, making transrectal palpation of the fetus impossible. Transabdominal ultrasonography revealed excessive amounts of fetal fluid. Results of analysis of fluid obtained via amnio- and allantocentesis confirmed that the amniotic cavity was large.
Treatment and Outcome—The mare was monitored for signs of weakness of the prepubic tendon and abdominal wall. The fetus and placenta were monitored for signs of stress and pending abortion. Flunixin meglumine and altrenogest were administered to the mare. Parturition was attended and occurred at 321 days' gestation. Postpartum complications in the mare included hypovolemic shock and cardiac arrhythmias. Both conditions were treated, and the mare recovered. The foal was considered small, had bilateral angular limb deformities, and was unable to nurse. The foal was given plasma for failure of passive transfer of immunity. Ten months later, the foal underwent procedures to correct limb deformities.
Conclusions and Clinical Relevance—Hydrops conditions are rare in horses, with hydrops allantois occurring more frequently than hydrops amnion; reportedly result in fetal or neonatal death; and may result in death of or injury to the mare. Close monitoring of maternal and fetal health in combination with supportive treatment of the mare can result in the safe progression of a hydrops pregnancy and the birth of a live foal.