Correlación entre los defectos de aplomo y la cojera del caballo

AUTOR(ES)
DATA DE PUBLICAÇÃO

2000

RESUMO

One hundred and seventy horses (144 males and 26 females) were studied to assess the influence of defects on limb conformation on the development of lameness. Animals were used for sport or pleasure, and most of them (N= 108, 63,5%) were Andalusian horses. Horses with or without lameness were selected according to the presence of conformational defects on the fore-, hindlimbs or both. A clinical and a radiographical study were performed in all horses. At least two 90 radiographic views were obtained from each anatomical region, from carpus and tarsus to distal points. The possible influence of the mediolateral foot imbalance on the frog direction and of the dorsopalmar foot imbalance on the presence of radiographical signs in the distal phalanx and in the navicular bone were assessed in some animals. As an ancillary method, four biokinematical analyses with computer-assisted videographic system were done in Andalusian horses to study the possible influence of craniocaudal and mediolateral limb deviations on quantitative and qualitative variables of equine limb movements. The most frequent defects observed in the forelimbs were the standing under in front (N=88; 52%), toe-out (N=45; 26%), toe-in (N=41; 24%), base-narrow (N=24; 14%) and base-wide (N=19; 11%). In the hindlimbs, standing under behind (N=35; 20,5%), cow hocks (N=16; 9%) and sickle hocks (N=14; 8%) were mainly found. Our results showed that mediolateral deviations of the foot produced a higher incidence of lesions in the medial surface of phalanxes but there was no conformational influence. In other cases, an obvious relationship between craniocaudal deviations and the radiographic signs could be observed, but not with lameness. Then, a higher incidence of osteophytes on the dorsoproximal surface of phalanxes and on the dorsal surface of the hock joints was found in horses with the standing under in front defect and with the standing under behind defect, respectively. No relationship could be detected between mediolateral imbalances of the foot and the frog direction and between dorsopalmar imbalance and the development of radiographical signs in the distal phalanx and navicular bone. Biokinematical studies showed significant changes in the overtracking length at trot and in the forefetlock joint at walk in horses with the standing under in front defect. In horses with the standing under behind conformation, differences could be detected in the hindlimb retraction-protaction angle at trot, in the stance and swing duration at walk and in the hindlimb corona elevation with relation to the ground at both gaits. Horses with both defects (standing under in front and behind) showed changes in the forelimb retraction-protaction angle in both gaits, in the hindlimb retraction-protaction angle at trot, and in the hindlimb corona elevation at walk. In mediolateral deviation analysis, toe-out horses showed a displacement of their forelimbs with an inward arc. In summary, the limb conformational defects of horses are frequent, particularly in Andalusian horses; however, the incidence of lameness is small. The radiographical changes occur in a progressive way. When conformational defects are not marked, and mainly if the activity is not intense, horses seemingly adapt themselves to the defect, without showing any radiographical signs or lameness. Videographic analyses, although not being routine methods for lameness diagnosis, are useful to understand the movement in animals with conformational defects.

ASSUNTO(S)

medicina veterinaria eqüinos caballos

ACESSO AO ARTIGO

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