Abstract

The present study records recurrent outbreaks of myelodysplasia of unknown origin occurring in a specific geographical location in the north of Spain, and involving up to 30% of the calves born in affected herds. The affected calves were of different breeds and displayed non-progressive signs of spinal cord dysfunction. The disease has occurred annually in February-March over a period of at least 15 years. Only calves born to cattle grazed on mountainside pastures and under high grazing pressure were affected. Seven calves were subjected to necropsy examination. Myelodysplasia was not associated with vertebral defects or arthrogryposis and involved the entire length of the spinal cord. Microscopically, there was abnormal distribution of the grey matter, aberrations of the central canal and failure of formation of the ventral median fissure. Infectious, nutritional and physical disorders were ruled out as possible aetiologies. A critical period of embryonic susceptibility to the causal agent was identified. This was during the time of secondary neurulation when cows in the early stages of gestation were grazed on mountainside pastures. Consequently, the presence of neuroteratogenic plants in these pastures is proposed as a likely cause. Two plants, Carex brevicollis and Erythronium dens-canis, which contain alkaloids, were identified on the mountainsides where affected cattle were grazed and not in other pastures, and are proposed as the possible aetiology of the disease.

Links

Publisher Full Text

Authors

Polledo L, García Marín JF, Martínez-Fernández B, González J, Alonso J, Salceda W, García-Iglesias MJ

Institution

Pathological Anatomy Section, Animal Health Department, University of León, León 24007, Spain. lpolr@unileon.es

Source

Journal of comparative pathology 147:4 2012 Nov pg 479-85

MeSH

Animals
Animals, Newborn
Cattle
Cattle Diseases
Disease Outbreaks
Female
Gestational Age
Nervous System Malformations
Neural Tube Defects
Plants, Toxic
Recurrence
Seasons
Spinal Cord
Time Factors

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

22520815