Significance of flexor tendon ultrasonography in training thoroughbreds

Coordenação de Aperfeiçoamento de Pessoal de Nível SuperiorThe cross-sectional area (CSA) of the superficial digital flexor tendon (SDFT) and deep digital flexor tendon (DDFT) of twenty four thoroughbreds was ultrasonographically evaluated before and during their initial training to determine the effect of exercise on the tendon CSA, texture and echogenicity to characterize the response to training. Ultrasonographic transverse images of the left forelimb were obtained every fifteen days. The SDFT CSA of zones IA and IIIA showed a decrease (p<0.05, f=0.010 e f=0.023 res.) during the breaking and training period and an increase (p< 0.05) of zone IIIC (f=0.039). Evaluating just the training period, SDFT CSA results of zones IA, IIIA and IIIC were similar. The DDFT showed no variation during the breaking phase but when the training phase was evaluated there was a decrease(P<0.05) in zones IA (f=0.006) and IIIA(f=0.006). Evaluating both breaking and training periods the DDFT showed a decrease (P<0.05) in zones IA (f=0.027), IIIA (f=0.0001) and IIIB (f=0.0031). Fiber texture and tendon echogenicity showed no significant difference between breaking and last reading during training. This study failed to provide evidence of ultrasonographic image variations that would indicate adaptation of both SDFT and DDFT to exercise during training of thoroughbred horses.Vinte e quatro potros Puro Sangue de Corrida (PSC), com dois anos de idade foram avaliados ultra-sonograficamente, durante o período final da doma e início de treinamento, através da imagem transversal dos tendões flexor digital superficial (TFDS) e profundo (TFDP). As avaliações foram realizadas com intervalos de 15 dias. A área transversal (AT), a textura dos ecos e a ecogenicidade dos tendões foram avaliadas nas sete zonas da região metacarpiana através de um programa de mensuração de imagens do próprio aparelho de ultra-sonografia. Durante a doma e treinamento houve diminuição da AT na zona IA e IIIA (p<0,05, f=0,001 e 0,0266 resp.) e aumento da zona IIIC (p< 0,05 f=0,0391) do TFDS. Ao considerar apenas o período do treinamento, o resultado foi semelhante (p<0,05) na zona IA (f=0,010), IIIA (f=0,023) e IIIC (f =0,0391). O TFDP apresentou uma diminuição na AT durante a doma e treinamento nas zonas IA, IIIA e IIIB (p<0,05, f=0,027; f=0,0001 e f=0,0031 resp.) e nas zonas IA e IIIA durante o treinamento (p