RESUMEN
Objective: To characterize concentrations of adrenocorticotropic hormone (ACTH), insulin, and thyroxine (T4) at 2 times of the year in healthy horses in Saskatchewan. Animals and procedure: A prospective, observational study was carried out in 52 healthy, client-owned horses. Inclusion criteria were no recent travel outside of Saskatchewan, normal physical examination findings, and no history or evidence of ongoing illness. Blood concentrations of ACTH, insulin and T4 were determined by chemiluminescence. Samples were collected in spring and fall and compared using the paired Student's t-test or Wilcoxon signed-rank test. Generalized estimating equations were used to assess the associations between ACTH, T4, and insulin concentrations and gender, age, season, body condition score, glucose concentration, and breed. Results: There were increases in both ACTH and insulin concentrations in the fall compared to spring (P < 0.001 and P = 0.001, respectively). Other than season, insulin concentration was associated with breed, whereas ACTH concentration was associated with age. Finally, T4 concentration was associated with breed and glucose concentration, but not with season. Conclusion and clinical relevance: These results highlighted the differences between spring and fall concentrations of both ACTH and insulin in healthy horses residing in the Canadian prairie provinces, which are known for extreme differences in summer and winter temperatures as well as day length. Geographically adjusted reference values are necessary to account for these variations, to improve diagnostic accuracy. This is the first published Canadian study evaluating these factors and their associations with hormone concentrations in clinically healthy animals.
Concentrations sanguines printanières et automnales d'hormone adrénocorticotrope, d'insuline et de thyroxine chez des chevaux en bonne santé en Saskatchewan. Objectif: Caractériser les concentrations d'hormone adrénocorticotrope (ACTH), d'insuline et de thyroxine (T4) à 2 moments de l'année chez des chevaux en bonne santé en Saskatchewan. Animaux et procédure: Une étude observationnelle prospective a été réalisée auprès de 52 chevaux en bonne santé appartenant à des clients. Les critères d'inclusion étaient l'absence de voyage récent à l'extérieur de la Saskatchewan, les résultats normaux de l'examen physique et l'absence d'antécédents ou de signes de maladie persistante. Les concentrations sanguines d'ACTH, d'insuline et de T4 ont été déterminées par chimiluminescence. Des échantillons ont été collectés au printemps et à l'automne et comparés à l'aide du test de Student apparié ou du test du rang de signe de Wilcoxon. Des équations d'estimation généralisées ont été utilisées pour évaluer les associations entre les concentrations d'ACTH, de T4 et d'insuline et le sexe, l'âge, la saison, l'état corporel, la concentration de glucose et la race. Résultats: Il y avait une augmentation des concentrations d'ACTH et d'insuline à l'automne par rapport au printemps (P < 0,001 et P = 0,001, respectivement). Hormis la saison, la concentration d'insuline était associée à la race, alors que la concentration d'ACTH était associée à l'âge. Enfin, la concentration de T4 était associée à la race et à la concentration en glucose, mais pas à la saison. Conclusion et pertinence clinique: Ces résultats ont mis en évidence les différences entre les concentrations printanières et automnales d'ACTH et d'insuline chez les chevaux en bonne santé résidant dans les provinces des Prairies canadiennes, reconnues pour leurs différences extrêmes de températures estivales et hivernales ainsi que de durée du jour. Des valeurs de référence géographiquement ajustées sont nécessaires pour tenir compte de ces variations et améliorer la précision du diagnostic. Il s'agit de la première étude canadienne publiée évaluant ces facteurs et leurs associations avec les concentrations d'hormones chez des animaux cliniquement sains.(Traduit par Dr Serge Messier).
Asunto(s)
Hormona Adrenocorticotrópica , Insulina , Humanos , Caballos , Animales , Tiroxina , Estaciones del Año , Saskatchewan , Estudios Prospectivos , GlucosaRESUMEN
Laminitis is a severely debilitating and life-threatening condition that occurs as a consequence of different primary triggering factors. Continuous digital hypothermia (CDH) is recommended in horses at risk of, or diagnosed with, acute laminitis due to its several physiological and biochemical alterations that may be positive for the prevention and early treatment of the condition, representing a low risk of adverse effects. Modulation of the inflammatory response, profound vasoconstriction, and prevention of tissue damage are the most notable protective effects of cryotherapy on the lamellae. This practical review aims to summarize the published literature evaluating CDH efficacy in the prevention and early treatment of acute laminitis in horses, highlighting the most important clinical findings and discussing the best methods to provide cryotherapy. Nineteen publications evaluated different CDH methods, including the use of commercially available ice boots or fluid bags filled with iced water or crushed ice, as well as alternatives to immersion in ice, e.g., frozen gel packs and a perfused cuff prototype. Although some techniques were effective for cooling and maintaining the hooves below the optimal temperature of 10 °C, relevant limitations such as labor intensiveness, reliance on an ice source and price make its use impractical in some clinical situations. Twelve experimental studies assessed the efficacy of CDH on the prevention or early treatment of laminitis, finding multiple positive effects in terms of clinical improvement, immunological and inflammatory modulation, and histological protection. After the analysis of the literature, the clinical importance of CDH in different stages of laminitis remains clear. However, it also highlights the need for a safer, more user-friendly, and more effective method of cryotherapy that can be used both in a hospital and an ambulatory setting.