Uterine Inertia due to Severe Selenium Deficiency in a Parturient Mare

Selenium in Bodily Homeostasis: Hypothalamus, Hormones, and Highways of Communication

The ability of the body to maintain homeostasis requires constant communication between the brain and peripheral tissues. Different organs produce signals, often in the form of hormones, which are detected by the hypothalamus. In response, the hypothalamus alters its regulation of bodily processes, which is achieved through its own pathways of hormonal communication. The generation and transmission of the molecules involved in these bi-directional axes can be affected by redox balance. The essential trace element selenium is known to influence numerous physiological processes, including energy homeostasis, through its various redox functions. Selenium must be obtained through the diet and is used to synthesize selenoproteins, a family of proteins with mainly antioxidant functions. Alterations in selenium status have been correlated with homeostatic disturbances in humans and studies with animal models of selenoprotein dysfunction indicate a strong influence on energy balance. The relationship between selenium and energy metabolism is complicated, however, as selenium has been shown to participate in multiple levels of homeostatic communication. This review discusses the role of selenium in the various pathways of communication between the body and the brain that are essential for maintaining homeostasis.

Good prognosis for survival to hospital discharge in a group of horses with uterine prolapse treated at a veterinary medical teaching hospital

OBJECTIVE

To describe uterine prolapse, predispositions, and outcomes in mares treated between 1988 and 2019.

ANIMALS

24 mares with uterine prolapse.

PROCEDURES

Clinical records were retrospectively reviewed, and follow-up information was gathered. The Mann-Whitney U test and Fisher exact test were used to analyze results for history and outcome variables for potential association with mare survival to hospital discharge. The χ2 test was used to compare breed distribution.

RESULTS

Age was known in 23 mares (median, 11.1 years). For 15 mares with exact known parity, the median parity was 3 births (range, 1 to 13 births). For 22 mares, the maiden status was known (7 [32%] maiden; 15 [68%] multiparous). Breed distribution differed significantly between mares with uterine prolapse and all mares treated at the Veterinary Medical Teaching Hospital. Arabians were overrepresented in the uterine prolapse group (7/24 [29%]), compared with all mares treated (4,174/44,474 [9%]). Uterine prolapse occurred within 2 hours after parturition for 10 of 11 mares with known foaling times, after dystocia for 7 mares, and after abortion for 4 mares. Seventeen of 23 (74%) mares survived to hospital discharge. Acute hemorrhage was the most frequent cause of death. There were no correlations between mare survival to hospital discharge and mare parity or age, foal sex, retained fetal membranes, sepsis, or maiden status. Colts were overrepresented in foals with a known sex (12/17).

CLINICAL RELEVANCE

Results indicated a breed predisposition to uterine prolapse, with Arabian mares overrepresented among affected mares. No characteristics correlated with mare survival to hospital discharge.