Social facilitation of trotting: Can horses perceive and adapt to the movement of another horse?

Exercise intensity is prone to be self-regulated in horses exercising freely. The main drivers include social, feeding and escape behaviors, as well as the operant conditioning. We hypothesized that self-regulated exercise intensity may increase due to the presence of another horse exercising ahead. Seven horses were assigned to a 2x2 crossover trial following treadmill familiarization. Video images of a trotting horse were displayed on the wall in front of the experimental unit (Visual), which was positioned in the treadmill. Physiological and behavioral markers were further compared with a control visual stimulus (Co), comprising a racetrack image without horses. Horses were sampled during a constant load exercise test (1) at rest (baseline), (2) after the warm-up (0 - 10th minute) and (3) after visual stimulation or control (10th- 12th minutes of the SET) to quantify plasma lactate and glucose concentration, heart rate, head angle, as well as behavioral markers. Following visual stimulation, heart rate (130.8 ± 27.8 b.p.m.) was higher than control (84.7 ± 15.1 b.p.m., P = .017), as was plasma lactate (Visual - 5.28 ± 1.48 mg/dl; Co -3.27 ± 1.24 mg/dl, P = .042) and head angle (Visual - 36.43 ± 3.69°; Co -25.14 ± 4.88°, P = .003). The prevalence of "ears forward" behavior was also higher following Visual (100% - 7/7) than Co (14% - 1/7, P = .004). These results suggest that visual stimulus (1) was safe and well tolerated and (2) prompted the anaerobic lactic pathways and shifted the behavior to a vigilant state. In conclusion, horses were able to perceive and adapt to a social environment. Our findings validate the use of social facilitation of trotting to encourage horses to move forward avoiding the use of the whip.

Evaluation of platelet-rich plasma applied in the coronary band of healthy equine hooves.

Platelet-rich plasma (PRP) is a widely used hemocomponent that holds great promise in equine medicine due to its feasible production and regenerative therapy potential. Its use has been considered as a treatment for chronic laminitis, mainly in terms of its analgesic properties and because it can induce growth in affected hooves. The aim of this study was to evaluate the effect on hoof growth attributable to PRP applied in the coronary band of clinically healthy horses by comparing the responses to PRP, saline, and trimming alone. After randomization, the forelimbs of 9 horses received specific treatment at intervals of 33 days and were trimmed, measured, and radiographed at the same time. Neither hoof growth nor hoof angles were different between the treatment groups at any time point. The application of PRP in the coronary band of horses may be a safe procedure; however, it had no effect on the growth or conformation of hooves in clinically healthy horses.

Évaluation du plasma riche en plaquettes appliqué dans la bande coronaire de sabots équins sains. Le plasma riche en plaquettes (PRP) est un hémo-composant largement utilisé qui est très prometteur en médecine équine en raison de sa production réalisable et de son potentiel de thérapie régénérative. Son utilisation a été considérée comme un traitement de la fourbure chronique, principalement en termes de ses propriétés analgésiques et parce qu'elle peut induire la croissance des sabots atteints. Le but de cette étude était d'évaluer l'effet sur la croissance des sabots attribuable au PRP appliqué dans la bande coronaire de chevaux cliniquement sains en comparant les réponses au PRP, à la solution saline et à la taille seule. Après randomisation, les membres antérieurs de neuf chevaux ont reçu un traitement spécifique à des intervalles de 33 jours et ont été taillés, mesurés et radiographiés au même moment. Ni la croissance ni les angles des sabots n'étaient différents entre les groupes de traitement à aucun moment. L'application de PRP dans la bande coronaire des chevaux peut être une procédure sûre; cependant, il n'a eu aucun effet sur la croissance ou la conformation des sabots chez les chevaux cliniquement sains.(Traduit par Dr Serge Messier).

Physical exercise on serum electrolytes and acid base balance in Mangalarga Marchador horses submitted to cavalcade of 4, 8 and 20km / Influência do exercício físico sobre o equilíbrio ácido base e hidroeletrolítico em cavalos da raça Mangalarga Marchado submetidos a provas de cavalgadas de 4, 8 e 20km

ABSTRACT: Acid-base and electrolyte disorders have been described in horses associated during and after exercise. The aim of the present study was to evaluate the effect of cavalcade competition on the acid-base and hydroelectrolytic balance in Mangalarga Marchador horses. For this purpose, 15 geldings, 6.2 ± 1.2 years old and clinically healthy, were distributed into three groups of five animals each. Horses were trained to take part in cavalcade competitions. Animals were submitted to cavalcade along 4km (G4), 8km (G8), and 20km (G20) at mean speeds of 15km h-1, 12km h-1, and 12km h-1, respectively. From each horse, venous blood samples were collected before exercise (T0) and immediately after (T1) cavalcade. Bicarbonate ion (HCO3-), pH, partial pressure of carbon dioxide (pCO2), partial pressure of oxygen (pO2), base excess (BE), hematocrit (Hct), sodium (Na+), potassium (K+), chloride (Cl-) and lactate were determined. The variables pH, pO2 and pCO2 were corrected in function of rectal temperature of each animal. Blood samples were analyzed for acid-base balance, as well as biochemical and electrolyte parameters using an i-STAT analyzer. Significant (P<0.05) increase in Hct, Na+, pH, HCO3 - and BE were observed after cavalcade in G20 group. Decrease (P<0.05) in K+ and Cl- were also observed in G20 animals after cavalcade (T1). Changes in the acid-base balance and hydroelectrolytic profile of the Mangalarga Marchador after cavalcade of 20km resulted in hypochloremic metabolic alkalosis. The 20km cavalcade induced significant hydroelectrolytic and acid-base imbalances in Mangalarga Marchador horses.

RESUMO: Distúrbios ácido-base e eletrolíticos têm sido descritos em cavalos durante e após diferentes modalidades de exercícios. Este estudo foi realizado com o objetivo de investigar o efeito do esforço físico de cavalgada sobre o equilíbrio ácido base e hidroeletrolítico de cavalos da raça Mangalarga Marchador. Quinze cavalos castrados com média de idade de 6.2±1.2 anos foram distribuídos em três grupos com 05 indivíduos cada. Os animais percorreram percursos de 4 (G4), 8 (G8) e 20 (G20) km de extensão os quais, foram realizados à velocidade média de 15km h-1, 12km h-1 e 12km h-1, respectivamente. Íon bicarbonato (HCO3 -), pH, pressão parcial de dióxido de carbono (pCO2), pressão parcial de oxigênio (pO2), excesso de bases (BE), hematócrito (Hct), sódio (Na+), potássio (K+), cloreto (Cl-) e lactato foram mensurados. As variáveis pH, pO2 e pCO2 foram corrigidas em função da temperatura corporal dos animais. De cada cavalo, amostras de sangue venoso foram coletadas antes do exercício (T0) e após o término da cavalgada (T1). As amostras foram analisadas através do i-STAT. Houve aumento (P<0,05) nos valores de Hct, Na+, pH, HCO3 - e BE nos animais do G20, após o término da cavalgada (T1). Após a cavalgada, os animais do G20 apresentaram ainda diminuição na concentração de K+ e de Cl-. As alterações no equilíbrio ácido-base e hidroeletrolítico pós-cavalgada de 20km resultou em alcalose metabólica hipoclorêmica. O esforço físico de cavalgada de 20km resultou em desequilíbrios hidroeletrolíticos e ácido-base significativos em cavalos da raça Mangalarga Marchador.