Nocardioform placentitis in a sample population of mares foaling in southeastern Pennsylvania and northeastern Maryland in 2020.

Nocardioform placentitis (NP) has been associated with mid to late pregnancy loss in mares. To date, disease outbreaks have been described only in central Kentucky, although sporadic, isolated cases have been reported globally. This study describes a series of cases of NP that occurred in a sample population of 299 mares foaling in southeastern Pennsylvania and northeastern Maryland in 2020. These cases coincided with an outbreak of NP that occurred in Kentucky that same year. On farms that reported information on both normal and abnormal foalings, nocardioform organisms/DNA were isolated from 6.3% of placental samples based on aerobic culture and/or PCR. In cases with characteristic gross lesions of the chorion, 41% of cases were positive on aerobic culture and/or PCR. NP was confirmed in 16 mares that had not resided in Kentucky for breeding or any part of gestation. Characteristics of mares confirmed positive for NP, including age, gestation length, and problems during gestation are described. Standardbred mares bred by artificial insemination were less likely to be affected than Thoroughbred mares bred by natural cover. Affected mares had prolonged Stage III labor compared with normal mares. These findings suggest that regional increases in NP may occur outside of Kentucky, potentially in parallel with Kentucky outbreaks.

Alkaline phosphatase in stallion semen: characterization and clinical applications.

Significant amounts of alkaline phosphatase (AP) activity have been found in semen plasma from numerous species. In species in which the majority of semen plasma AP (SPAP) activity originates from the epididymis and testicle, SPAP activity can be used clinically as a marker to differentiate testicular origin azoospermia or oligospermia from ejaculatory failure. Information on SPAP activity in stallions to date has been limited. In this study, a standard clinical chemistry analyzer was used to determine AP activity in pre-ejaculatory fluid and ejaculates from groups of normal stallions. Additionally, accessory glands, epididymides, testicles and other components of the urogenital tract of normal stallions were assayed to determine which tissues contain SPAP activity. The results indicated that levels of AP activity are low in pre-ejaculatory fluid, but significantly higher in ejaculatory fluid from normal stallions. Spermatozoa were not a significant source of SPAP activity. High levels of SPAP activity were found in the testes and epididymides. These findings suggest that SPAP activity is a candidate for a sperm-independent marker for ejaculation in the stallion. Finally, AP activity was determined in ejaculatory fluid from a stallion with bilaterally blocked ampullae, both before and after relief of the blockage. While the blockage was present, AP activity in ejaculatory fluid was low. However, following relief of the blockage, AP activity in ejaculatory fluid rose dramatically, thus suggesting that AP activity will be useful as an inexpensive, simple clinical assay for differentiating ejaculatory failure or excurrent duct blockages from testicular origin azoospermia and oligospermia.