NICOTIANA-GLAUCA-INDUCED CONGENITAL DEFORMITIES IN CALVES - CLINICAL AND PATHOLOGIC ASPECTS

Abstract

Foraged plants are incriminated as teratogenic agents responsible for congenital deformities of livestock. Seven calves born to 7 cows fed N. glauca during portions of the 1st trimester of gestation were deformed at birth. Deformities increased in severity as the calves aged. At birth calves typically had arthrogryposis of the forelimbs or curvature of the spine; severity varied among calves. In 4 calves necropsied at .apprx. 15 mo. of age, there was general malpositioning and misalignment of the distal ends of the radius and ulna and the proximal ends of the metacarpal bones. Carpal joints were severely affected, fetlock joints were moderately affected and pastern joints were slightly affected with lateral rotation of forelimbs common; severity varied among calves. In 1 of the 4 calves, there was moderate torticollis and scoliosis resulting from wedging of some of the cervical and thoracic vertebrae and abnormal cranial curvature of the left thoracic ribs. Histologic changes were not noticed in muscle, brain, spinal cord or endocrine organs of the 4 calves.