Chiropractic effects on stride parameters and heart rate during exercise in sport horses.

BACKGROUND: Equine veterinarians performing chiropractic treatments are frequently asked to evaluate and treat sound horses to improve their performance and address pain associated with the axial skeleton. Studies describing the effects and mechanisms of chiropractic treatments in horses without overt lameness are scarce. OBJECTIVES: This study aimed to evaluate the effect of chiropractic treatments on stride rate, length, symmetry, heart rate and rider-perceived quality of the ridden work in sport horses. STUDY DESIGN: A blind randomised controlled trial with crossover design. METHODS: Thirty-eight horses ridden in the hunter-jumper discipline were enrolled. Exercise tests were recorded before and after chiropractic or sham treatment while horses were wearing a fitness tracker. Stride length, rate and symmetry, heart rate and the perceived quality of the ridden work were compared. RESULTS: There was a difference in the qualitative assessment of the ridden work by riders between treatments (odds ratio 33.8, 95% CI [4.68, 458.71], p < 0.01). Stride length, rate, symmetry and heart rate were not different between treatments. MAIN LIMITATIONS: The quantitative outcomes measured may not be sensitive enough to detect changes that improve the ridden work. Terrain, weather and rider were not standard across horses making small changes difficult to detect. CONCLUSIONS: Riders participating in a blind randomised controlled trial perceived a positive effect of chiropractic treatments on the quality of the ridden work. There were no differences in stride length, stride rate, stride symmetry or heart rate. The mechanisms, indications and potential benefits of chiropractic treatments in horses need further study.

HISTORIAL: A los veterinarios de equinos que realizan tratamientos quiroprácticos, se les pide frecuentemente evaluar y tratar caballos que están sanos para mejorar su desempeño y tratar el dolor asociado con el esqueleto axial. Estudios que describen los efectos y mecanismos de los tratamientos quiropráctico en caballos sin cojeras aparentes, son pocos. OBJETIVOS: Este estudio tiene por objetivo evaluar el efecto de los tratamientos quiroprácticos sobre frecuencia, largo y simetría de la zancada, la frecuencia cardiaca y la calidad del trabajo montado percibida por el jinete en caballos de deporte. DISEÑO DEL ESTUDIO: Prueba aleatoria cegada controlada con diseño cruzado. MÉTODOS: Se enrolaron 38 caballos montados en la disciplina de caza-salto. Pruebas de ejercicio fueron anotadas antes y después de tratamientos quiropráctico reales o simulados mientras los caballos llevaban un monitor físico. Se compararon el largo, frecuencia y simetría de la zancada, frecuencia cardiaca y calidad del trabajo montado percibida por el jinete. RESULTADOS: Se encontró una diferencia en la evaluación cualitativa del trabajo montado por los jinetes entre los tratamientos (odds ratio 33.8, 95% CI [4.68, 458.71], p < 0.01). Largo, frecuencia y simetría de zancada y frecuencia cardiacas no difirieron entre tratamientos. LIMITACIONES PRINCIPALES: Los resultados cuantitativos medidos, pueden no ser lo suficientemente sensibles para detectar cambios que mejoran el trabajo montado. El terreno, tiempo y jinete no fueron estandarizados a través de los caballos, lo que hizo que cambios pequeños fuesen difíciles de detectar. CONCLUSIONES: Los jinetes que participaron en una prueba aleatoria cegada controlada, percibieron un efecto positivo de los tratamientos quiroprácticos sobre la calidad del trabajo montado. No hubo diferencia en largo de zancada, frecuencia de zancada, simetría de zancada o frecuencia cardiaca. Los mecanismos, indicaciones y beneficios potenciales de los tratamientos quiroprácticos en caballos necesitan ser estudiados mas.

Transfer of naturally acquired specific passive immunity against Anaplasma phagocytophilum in foals in Southeastern Pennsylvania and Northern Maryland.

BACKGROUND: Equine granulocytic anaplasmosis (EGA) is a common disease in adult horses, but clinical disease in foals is rarely reported. The relationship between equine maternal and neonatal antibodies to Anaplasma phagocytophilum is unclear. HYPOTHESIS/OBJECTIVES: That mares in an endemic region would be seropositive for A. phagocytophilum and that mare and foal serum IgG concentrations for A. phagocytophilum would correlate. Additionally, we hypothesized that foal IgG concentrations for A. phagocytophilum acquired by passive immunity would decline by 6 months of age. ANIMALS: Twenty-two healthy mare-foal pairs. METHODS: This prospective observational study investigated serum IgG concentrations specific for A. phagocytophilum in mares and foals using an immunofluorescent antibody test (IFA). The association between foal titer (as a binary variable) and age in months was assessed using a mixed-effects logistic regression. RESULTS: A positive correlation between newborn foal antibody titers and mare titers was identified at both the pre-foaling (τa = 0.38, τb = 0.50, P = .009) and foaling timepoints (τa = 0.36, τb = 0.47, P = .01). In A. phagocytophilum seropositive neonates, it was unlikely that a positive titer would be detected by 3 months of age (OR = 0.002, P = .02, 95% CI: 0.00001-0.38). Three out of 20 foals seroconverted between 3 and 6 months of age. CONCLUSIONS AND CLINICAL IMPORTANCE: Transfer of specific passive immunity to A. phagocytophilum occurred in 80% of foals born to seropositive mares and declined by 3 months of age. A. phagocytophilum infection should be considered in foals displaying clinical signs consistent with EGA.