Beta-hemolytic Streptococcus equi subsp. zooepidemicus (BHS) is the most frequently isolated pathogen in the uterus of mares. However, in a large fraction (>50%) of subfertile mares there is no obvious reason identified. We recently demonstrated that BHS have the ability to reside deep in endometrium and may also gain intracellular access. The ability to escape and hide from the immune system allows BHS to cause long lasting, hardly detectable infections. In addition to this, we have shown that BHS are able to enter a dormant state where the bacteria can slow down their metabolism. Most antibiotics inhibit bacterial growth by disrupting the microbial metabolism which makes the dormant bacteria highly tolerant to antibiotics.

Age-related testicular degeneration is a common problem in older stallions. This type of testicular degeneration is different than the degeneration that can be seen after, for example, an injury to the testes in a younger stallion. Following testicular trauma, many stallions are able to fully recover. However, age-related testicular degeneration results in progressive deterioration of the testes and an associated progressive decline in testicular function. Over time, affected stallions become progressively more subfertile and eventually may become sterile in association with decreases in semen quality, sperm numbers and testicular size. There is no proven treatment for age related testicular degeneration, although many therapies have been tried.  In this article, Dr. Regina Turner of the New Bolton Center at the University of Pennsylvania, discusses the causes of age-related testicular degeneration, current research and how one can manage the breeding career of an aged stallion until a treatment or cure is found.

Send Us Your SBS Frozen Semen Foal Photos. Pull out your cameras and start snapping! We'd like to see photos of your foals born in 2019 (2018 if born August – December in the Southern Hemisphere) from semen frozen by an SBS affiliate lab or resulting from embryo transfer performed at one of our SBS affiliate labs. The winner of the best foal photo will win a $75 Dover Saddlery gift certificate (or for Amazon.com for submissions from EU/AUS). Photos will be posted to our website and will be judged on composition by our SBS affiliate members. Click here to see the submission of foals from 2018.

Breeding season is just around the corner and most breeders dread the frustration of subfertility in certain broodmares. A thorough breeding history is key to diagnosing the cause of subfertility. Questions that address previous breeding management, stallion selection, and general wellness are important when performing a breeding soundness evaluation. Diagnostics such as trans-rectal palpation and ultrasound examination of the reproductive tract, vaginal speculum examination, digital cervical palpation, endometrial cytology and culture, endometrial biopsy, and hysteroscopic examination are useful in determining the cause of subfertility. Typically, a cause of subfertility can be determined utilizing the diagnostics mentioned above, but there may be some cases in which diagnostic test results are negative and yet a mare is still subfertile. So what’s next?