Selenium levels of beef cattle in southeastern british columbia relative to supplementation and type of pasture

Moderate to extremely low levels of selenium in hay were related to marginally deficient levels of selenium in sera from cattle in the Windermere Valley of southeastern British Columbia. Deficiency was most pronounced in cattle fed local hay during the winter or grazed on fertilized/irrigated pastures. Cattle on range had adequate levels of serum selenium. When sodium selenite was fed at 1.0 and 3.5 mg per head per day, serum selenium levels increased commensurate with the dose. Clinical observations indicated that a variety of clinical problems disappeared after injection or supplementation with selenium/vitamin E.     

Cervical intervertebral disc protrusion in two horses

Two horses with ataxia of all four limbs were found to have cervical intervertebral disc protrusion. Severe pelvic limb ataxia, proprioceptive deficits and spasticity were present in both horses with similar but less severe signs in the thoracic limbs. Cerebrospinal fluid analysis was within normal limits. Metrizamide myelography allowed definitive diagnosis in one case when a compression of the spinal cord was demonstrated at the level of the second intervertebral space. In the second case, an intervertebral disc protrusion between cervical vertebrae 6 and 7 was found at necropsy. Fiber degeneration with poor myelin staining characterized the spinal cords histologically.     

Exercise in electrocardiographic interpretation

The response of the heart to disease can be detected by assessing myocardial electrical activity. The electrocardiograph is a useful diagnostic tool which is widely available to the veterinary clinician. However, interpretation of the tracing often requires considerable experience.     

A strategy for control of bovine leukemia virus infection: test and corrective management

Test and corrective management was applied in one dairy herd (130 milking cows) to control bovine leukemia virus infection. It consisted of: raising uninfected calves in order to establish a pool of uninfected replacement heifers, preventing transmission of bovine leukemia virus through transfer of blood from animal to animal and closing the herd. Regular herd testing was combined with selected changes in herd management. These procedures have been followed since January 1979. Prevalence of antibodies (as determined by gel-immunodiffusion) has declined markedly since the program was implemented.