Indications for and how to perform Caslick's operation in the mare

Abstract

The vulva functions as the most caudal of the three physical barriers between the uterine lumen and the outside world. A compromised vulval seal predisposes to pneumovagina (wind sucking) in mares and may lead to inflammation and ascending contamination of the caudal reproductive tract with pathogens, and/or urine pooling in the vagina. Abnormalities of a mare's perineal conformation and an inadequate vulval seal are most often corrected using Caslick's operation, a procedure that involves surgical apposition of the dorsal part of the vulval labia. The reasons for poor vulval conformation, and therefore the indications for a ‘Caslick's’, vary but can include advanced age, trauma induced by foaling, weight loss and, in some breeds, congenital predisposition. If Caslick's operation is insufficient to resolve the pneumovagina more invasive surgical procedures, such as vestibuloplasty or perineoplasty, should be considered.

Twin management in the mare: A review

“…The thoracic compression technique has been reported as a promising minimally‐invasive alternative for fetal destruction to manage twins from approximately 50 days of gestation onwards. The technique is performed by rectal manipulation and involves the isolation of the smallest or most easily accessible fetus with compression of its fetal neck/thorax between the ultrasound probe and the mare's pelvic brim/lateral abdominal wall by applying constant, increasing pressure to cause cardiac arrest, but without rupturing the chorioallantois 51–54 . Successful application results in faint valve movements or cardiac arrest immediately after performing the reduction or within 24 h. Cardiac arrest can be presented after a single session, however manipulation may need to be repeated on consecutive days 52 .…”

“…The technique is performed by rectal manipulation and involves the isolation of the smallest or most easily accessible fetus with compression of its fetal neck/thorax between the ultrasound probe and the mare's pelvic brim/lateral abdominal wall by applying constant, increasing pressure to cause cardiac arrest, but without rupturing the chorioallantois 51–54 . Successful application results in faint valve movements or cardiac arrest immediately after performing the reduction or within 24 h. Cardiac arrest can be presented after a single session, however manipulation may need to be repeated on consecutive days 52 . The combination of a tocolytic, spasmolytic drug and NSAIDs can be administered at the time of the procedure to facilitate the isolation of the fetus, prevent rectal straining and inhibit prostaglandin release.…”

“…The combination of a tocolytic, spasmolytic drug and NSAIDs can be administered at the time of the procedure to facilitate the isolation of the fetus, prevent rectal straining and inhibit prostaglandin release. In addition, post‐reduction treatment, including NSAIDs and progestin therapy can be administered, however this does not seem to be critical 52 . Regular ultrasonographic monitoring following this procedure is suggested to assess both the demise of the reduced fetus and the viability of the remaining fetus as an unsuccessful outcome is often not immediately apparent and abortion usually only occurs about 1 month after the procedure 52,53 .…”

“…In addition, post‐reduction treatment, including NSAIDs and progestin therapy can be administered, however this does not seem to be critical 52 . Regular ultrasonographic monitoring following this procedure is suggested to assess both the demise of the reduced fetus and the viability of the remaining fetus as an unsuccessful outcome is often not immediately apparent and abortion usually only occurs about 1 month after the procedure 52,53 . The thoracic compression technique is currently favoured and most effective between 55 and 65 days of gestation 52–54 and a live foal success rate of 60% (6/10; unilateral fixed twin pregnancies) can be expected 53 .…”

“…Regular ultrasonographic monitoring following this procedure is suggested to assess both the demise of the reduced fetus and the viability of the remaining fetus as an unsuccessful outcome is often not immediately apparent and abortion usually only occurs about 1 month after the procedure 52,53 . The thoracic compression technique is currently favoured and most effective between 55 and 65 days of gestation 52–54 and a live foal success rate of 60% (6/10; unilateral fixed twin pregnancies) can be expected 53 . Recently, Arnold et al 52 also reported a successful reduction to a singleton in 9 out of 10 (90%) dizygotic twins, seven of which have resulted in the birth of a normal sized single foal (70%).…”