This review describes the physiological role of cortisol in the horses’ body and the usefulness of cortisol concentration measurements in assessing welfare and diagnosing diseases. Cortisol is examined in terms of its production and functions, along with the concept of circadian cortisol rhythms and potential disruptions in these patterns. The significance of cortisol concentration is emphasized, as it provides insights into stress levels, and the connection between cortisol and stereotypical horse behaviors, raising the question of whether these behaviors signify stress or serve as coping mechanisms. Moreover, cortisol concentration helps in diagnosing various health conditions such as Cushing’s Disease, inflammation, and metabolic imbalances. As cortisol concentration is considered a stress indicator that may be affected by the sampling protocol, the matrices for cortisol sampling and their practical applications are summarized. In this review, three major cortisol sampling methods: plasma, salivary, and hair cortisol, are described in detail. Plasma cortisol measurements offer acute stress insights, while salivary cortisol analysis provides a non-invasive method for continuous stress monitoring. Hair cortisol, on the other hand, offers an assessment of long-term stress levels. This text underscores the importance of cortisol control in safeguarding the welfare and health of horses.

Infrared thermography is a valuable tool adapted for veterinary diagnostics with an increasing number of uses. However, proper image acquisition is hard, not only due to various factors affecting the image but also because informative image processing is a struggle. Thus, this study aims to quantify the area of maximum temperature (Area of Tmax) on the lateral surface of horses and foals to compare the Areas of Tmax between horses and foals and to compare two new approaches to the Area of Tmax quantification in horses. Infrared images were acquired with a thermographic camera from 12 horses and 12 foals in the same ambient condition. The backgrounds of the images were removed, and the images were then processed in Rainbow HC and a grayscale palette. Then, 10 images were created, showing the Areas of Tmax in gradually decreasing ranges. The evaluation of the Area of Tmax with two image processing methods showed higher maximum temperatures in foals, although the high-temperature values covered less of their total body area than in adult horses. The results indicate the struggles of foals with thermal homeostasis. The proposed methods—multi-colored annotated pixels on Rainbow HC and red-annotated pixels on grayscale—provide a common quality in the thermogram evaluation of foals and adult horses. Further research is essential to determine their diagnostic application.

Copper (Cu) and zinc (Zn) are trace minerals with multiple biological functions, playing roles in fetal development and immune regulation. Despite their known significance, research on Cu and Zn administration and supplementation for pregnant mares is insufficient. This study aims to evaluate Cu and Zn serum concentrations monthly throughout the year and through pregnancy in Polish Konik mares. The study was conducted in 2020 on 36 mares from the Polish state stud farm, with 24 mares in the pregnant group and 12 mares in the non-pregnant group. Monthly blood samples were collected, and serum Cu and Zn concentrations were measured. The total Cu concentration in the serum of all mares was higher (p < 0.0001) in August and September (13.98 ± 3.00 μmol/L) than in May, June, July, and November (11.04 ± 2.74 μmol/L). Similarly, the total Zn concentration was higher (p < 0.0001) in August, September, October, November, and December (19.80 ± 9.72 μmol/L) than in May, June, and July (14.50 ± 6.94 μmol/L). No evidence of a linear relation between Cu and Zn concentrations was demonstrated (slopes difference p < 0.001). No differences in Cu (p > 0.05) or Zn (p > 0.05) concentrations were found between pregnant (Cu: 12.08 ± 3.01 μmol/L; Zn: 18.02 ± 9.03 μmol/L) and non-pregnant (Cu: 11.23 ± 2.51 μmol/L; Zn: 18.59 ± 10.37 μmol/L) mares in any of the examined months of the year. In conclusion, the month of the year, rather than pregnancy, affects serum Cu and Zn concentrations.