Like most mammalian, polyphasic sleep, equine sleep can be divided into two phases: the REM (rapid eye movement) phase and the NREM (non-rapid eye movement) phase. For this study, a randomized crossover experiment was conducted using ten purebred Lusitano horses, all dressage athletes aged from three to seven years old. The horses were filmed before the intervention to characterize their sleep patterns. REM sleep deprivation was achieved by not letting the horses attain sternal or lateral recumbency for three consecutive days, totaling 72 h. A spatial memory task and a visual attention test were performed. A recording time of 48 h appeared to be long enough to characterize the sleep patterns of the stalled horses. The total recumbency time of the studied population was lower than that previously reported in horses. Although the recumbency times before and after the intervention were similar, there was a tendency shown by the delta (p = 0.0839) towards an increased time needed to resolve spatial memory tasks in the sleep-deprived group. Future studies may deepen the understanding of horse sleep requirements and patterns, and the effects of environmental changes on horse sleep.

Ozone (O3) therapy has been used for medical procedures for centuries; however, there are no extensive studies on its utilization in horses. This study aimed to evaluate the application of transrectal O3 on horses by physical and laboratorial evaluation, and production of reactive oxygen species (ROS). Sixteen healthy horses were separated in two groups: a control group (CG) and a group treated with O3 (TG). The TG animals received 1L of an oxygen and O3 mixture transrectally. The initial dose was 10µg/ml for the first two applications, 15μg/ml for the following two applications, and 20μg/ml for the next six applications. The CG animals received 1L of oxygen transrectally. In TG animals no variations in the physical examination were detected; furthermore, TG animals did not exhibit changes in biochemical evaluation results, fibrinogen concentrations, or ROS production. TG animals had increased red blood cell counts, hemoglobin concentrations, and packet cell volume values in comparison to the baseline and CG values. We could infer that O3 affected the red blood cell counts and improved rhetological properties of the blood. The transrectal application of O3 in horses is safe and can indirectly improve the oxygenation and metabolism of tissues.

Recumbency behavior is an indicator of rest, comfort, pain, and welfare in horses during hospitalization and postoperative recovery. Although arthroscopy and laparoscopy are minimally invasive procedures, their effects on postoperative recumbency patterns remain poorly characterized. To compare sternal and lateral recumbency times in horses undergoing arthroscopy or laparoscopy during the immediate postoperative period. Recumbency data from two independent experiments were analyzed. Eight horses underwent arthroscopy for experimental induction of osteoarthritis, and eight mares underwent standing laparoscopic ovariectomy; in both experiments, each animal underwent two procedures at defined intervals. Sternal and lateral recumbency times were recorded by continuous video monitoring for four days after each procedure. Preoperative recumbency, when available, was included as a covariate. General linear models evaluated the effects of surgical technique, surgery order, and postoperative day. Estimated marginal means were calculated for significant effects. Arthroscopy was associated with longer sternal (192.8 ± 20.2 vs. 85.0 ± 14.5 min; P < 0.001) and lateral recumbency times (38.3 ± 6.4 vs. 9.7 ± 4.7 min; P < 0.001) than laparoscopy. Postoperative day significantly influenced recumbency, with times increasing over the four-day period (P < 0.001). Surgery order had no significant effect. Preoperative sternal recumbency tended to persist postoperatively but did not explain differences between surgical techniques. Despite both being minimally invasive, arthroscopy and laparoscopy had distinct effects on postoperative recumbency behavior in horses. These findings suggest that recumbency patterns reflect surgical characteristics and postoperative adaptation, supporting their use as complementary indicators of recovery and welfare.