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.

Introduction: Horse racing is a major sport practiced worldwide. The environment to which horses are exposed during race meetings can influence their behavior. However, to the best of our knowledge, a method for assessing a horse’s response to its surroundings during the pre- and post-race periods has not yet been reported. This study aimed to create a standard list of descriptors for use in a qualitative behavioral assessment (QBA) focused on assessing the emotional expressivity of horses before and after racing events.Materials and methods: Seventy pre- or post-race 30-second videos of horses were randomly selected from our database of 700 videos. A panel of 8 experienced equine sports medicine specialist veterinarians watched a 60 min presentation on QBA. The panel then watched all videos randomly, simultaneously, individually, continuously, and without any verbal interaction, describing the descriptors related to the emotional expressivity of the horse after each video using a method known as free-choice profiling (FCP).Results: The initial selection of descriptors was based on those indicated by more than one evaluator in the same video, or descriptors with more than 20 occurrences. The second selection was performed based on the content validity index (CVR) to select the descriptors retained in the previous step. Another panel of six veterinarians scored each of the descriptors retained for content validity on a visual scale. Interobserver reliability was estimated using the intraclass correlation coefficient (ICC) and its respective 95% confidence intervals (CI). A natural language processing (NLP) algorithm was used to analyze the behavior (positive or negative polarity) of the descriptors based on the lexicoPT package of R software.Discussion/Conclusion: NLP analysis considered the descriptors “agitated,” “troubled,” “restless” and “irritated” to have a negative polarity, while “focused,” “relaxed” and “peaceful” had a positive polarity. In the principal component analysis (PCA), descriptors in a negative state were associated with each other and inversely associated with descriptors in a positive state. We conclude with a fixed list of descriptors to be used in a QBA to assess emotional and welfare expressivity in racehorses’ pre- and post-race environments.

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.

Several studies in human and equine medicine have produced controversial results regarding the role of dimethylsulfoxide (DMSO) as a therapeutic agent. This study aimed to evaluate the effect of joint lavage with different DMSO concentrations on biomarkers of synovial fluid inflammation and cartilage degradation in joints with lipopolysaccharide (LPS)-induced synovitis. Twenty-six tibiotarsal joints of 13 horses were randomly distributed into four groups (lactated Ringer’s solution; 5% DMSO in lactated Ringer’s; 10% DMSO in lactated Ringer’s; and sham). All animals were evaluated for the presence of lameness, and synovial fluid analyses were performed at 0 h, 1 h, 8 h, 24 h, and 48 h (T0, T1, T8, T24, and T48, respectively). The white blood cell counts (WBC), total protein (TP), urea, prostaglandin E2 (PGE2), interleukin (IL)-1β, IL-6, IL-10, tumor necrosis factor-α (TNF-α), hyaluronic acid (HA), and chondroitin sulfate (CS) concentrations were measured. The WBC counts and PGE2, IL-1β, IL-6, and TP concentrations increased in all groups at T8 compared to baseline values (p < 0.05). At T48, only the 5% DMSO and 10% DMSO groups showed a significant decrease in WBC counts (p < 0.05). Furthermore, the 10% DMSO group had lower concentrations of PGE2 and IL-1β at T48 than at T8 (p < 0.05) and presented lower IL-6 levels than the5% DMSO and lactated Ringer’s groups at T24. All groups showed an increase in CS concentration after LPS-induced synovitis. Joint lavage with 10% DMSO in lactated Ringer’s has anti-inflammatory but not chondroprotective effects.

Background: Despite hepatotoxic effects, imidocarb dipropionate is the drug of choice for treatment of equine piroplasmosis. It is important, therefore, to identify adjuvant therapies that may improve the safety of imidocarb dipropionate by reducing the risk of liver damage during its use. The aim of the present study was to evaluate the hepatoprotective and hepatoregulatory effects of treatment with Cynara scolymus and Silybum marianum during administration of imidocarb dipropionate. Methods: Ten healthy horses, seroconverted to Theileria equi by C‐ELISA, were treated with 5 mg/kg/day of imidocarb dipropionate for three consecutive days. The study population was divided into two groups. The control group did not receive any complementary treatments. The treated group received a daily oral supplement containing C scolymus and S marianum for 30 days. Physical, haematological and histological examinations of hepatic fragments were performed. Results: All haematological values remained within normal range for the study population. Histological analysis revealed that treated group animals had 62 per cent less lobular inflammation, 55 per cent less pigment accumulation, 65 per cent less steatosis and 57 per cent less portal inflammation than control group animals, with an equivalent percentage of hydropic degeneration. Conclusion: C scolymus and S marianum supplements resulted in beneficial hepatoprotective effects in horses treated with imidocarb dipropionate.