How do our breeding soundness exams compare? (Proceedings)

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How do our breeding soundness exams compare? (Proceedings)

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Aug 01, 2010

1. The basic reproductive examination

A basic reproductive examination includes obtaining a history, conducting a physical examination, evaluating the perineal conformation, and performing a rectal/ultrasonographic exam of the reproductive tract, vaginal speculum examination and digital examination of the cervix. Ancillary aids include uterine cytology and culture, endometrial biopsy and endoscopic examination of the reproductive tract. The latter diagnostics are chosen on a case by case basis. The importance of obtaining a complete reproductive and performance history can not be over stated. Clinical signs are frequently repeated from one cycle to the next and these findings provide important information as to the primary cause of the infertility. If a reproductive case is a referral from another veterinarian, discussing previous diagnostics, treatments performed and the veterinarian's opinion about the case provides valuable information on what should or should not be pursued. All clinical findings and treatment protocols should be recorded so if the mare does not become pregnant the data can be reviewed. A one page check off sheet that includes space (history, perineal conformation, physical exam etc.) to write one's findings is helpful in ensuring that a complete examination is performed.

External exam

The general physical condition of the mare and farm management should be appraised before transrectal evaluation of the reproductive tract as systemic problems such as poor body condition, laminitis or pain may adversely affect fertility. Mares with laminitis may accumulate uterine fluid because they have limited mobility. Abnormal estrous cycle length or lack of estrous cycles during the mare's natural cyclic season may be associated with dramatic drops in ambient temperature and subsequent weight loss, pain, uterine infection, or systemic endocrine abnormality such as Cushing's Disease or metabolic syndrome. Feeding or management changes, dental care or parasite control may be needed. Race mares brought directly from the track or performance mares completing their career may not handle group dynamics of a brood mare band. Placing a maiden race mare in a small paddock with another mare may improve her ability to cope. Mares housed in northern temperate climates require more energy in January, February and March as they expend more calories in the cold. Mares that lose weight in the early spring tend not to cycle properly even when placed under 14.5 or more hours of artificial light in December.

Because most uterine infections are due to bacteria or yeast ascending through the vagina, perineal anatomy must be evaluated critically. Conformational characteristics that correlate with high fertility include a long sloping hip, a sacroiliac joint located 3 or more inches dorsal to the tail setting (as viewed from the side) and a vulva that is no more that 10 to 20° off of vertical. Mares that pool intra-uterine fluid after breeding often are flat over their croup with a tail setting level with the sacral iliac joint and a sunken anus. The perineum is best evaluated during estrus, when relaxation and elongation of the vulvar lips are greatest. The integrity of the vulvar lips, the angulation of the vulva and the location of the dorsal commissure of the vulva in relation to the pelvis need to be evaluated. If the dorsal aspect of the vulva is more than 4 cm above the pelvis, or the vulvar lips are more than 20° off vertical, air and/or feces may be aspirated into the vestibule during estrus. The lips of the vulva should be parted to determine the integrity of the vestibulo-vaginal sphincter. The sphincter is intact when the labia can be spread slightly without air entering the cranial vagina. By parting the labia, the color and moisture of the vestibular walls can be assessed. Estrus produces a glistening pink to slightly red mucosa that is uniform in color and wet. Anestrus generally is reflected by a pale, dry mucosa; dark-red, muddy color or a splotchy color suggests inflammation. A white, tacky mucosa indicates progesterone dominance.

The perineal body may be defective in older, pluriparous mares. Damage may occur after repeated foalings, delivering a large foal, after a dystocia, or from poor reproductive conformation. The integrity of the perineal body can be assessed by placing one finger into the rectum (usually the second finger) and the thumb into the vestibule. A vestibuloplasty or "deep caslick's" may be required to prevent contamination of the anterior reproductive tract especially if the vestibulovaginal seal is lost.