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  • Author or Editor: Marjorie S. Claxton x
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SUMMARY

Electrodiagnostic visual testing (electroretinogram [erg] and visual-evoked potential [vep]) was performed on 5 ruminants (3 lambs, 1 kid, and 1 steer) with thiamine-responsive polioencephalomalacia (pem) and on 2 sheep with listeriosis. The lambs and kid had typical clinical signs of pem, especially blindness. In these animals, the erg was normal but the vep was abnormal. Follow-up recordings in the kid and 1 lamb indicated an improvement in vep recordings accompanying a gradual return of vision after thiamine treatment. Possible subtle changes in vep peak latencies could not be assessed because of lack of normative vep data for sheep and goats. All animals had complete return of vision (owner-assessed). The steer did not have signs of blindness, and the erg and vep were normal. Changes in vep accompanying permanent pem blindness are not known.

One sheep with suspected listeriosis had lack of menace response and palpebral and corneal reflexes, but had intact vision. The erg and vep were normal. The second sheep with suspected listeriosis had intact menace response and vision, but became acutely blind and died; the ERG was normal, but vep amplitudes were depressed.

Free access
in American Journal of Veterinary Research

SUMMARY

A method was developed to record cortical somatosensory evoked potentials (sep) from thoracic and pelvic limb stimulation in cows. Recordings were similar in latency and amplitude to those reported for horses. Correction for conduction pathway length did not alter the average latency values because the cows of the study were uniform in size; however, the data provided will enable use of this normative data with smaller or larger individual animals.

Although latency variability for the sep peaks was low, variability of the amplitude measurements was high. This observed variability was similar to that seen in other species. Validity of the recorded responses was indicated by lack of a tibial nerve sep in 1 cow that had been given a tibial nerve conduction block, using lidocaine, and by repeatability of the response in 2 recordings taken 1 year apart in the same cow.

Free access
in American Journal of Veterinary Research

Summary

Over an 8-year period, 8 beef cattle with mesothelioma were admitted to the Auburn University College of Veterinary Medicine and the Louisiana State School of Veterinary Medicine. Diagnosis was confirmed by histologic examination of affected tissues. Five bulls, 1 steer, and 2 cows were affected. Four of the bulls had scrotal swelling; 2 cows and 1 bull had ventral abdominal swelling. The peritoneal cavity was involved in 5 cases, the pleural cavity was affected in 2 cases, and in 2 cases, disease was apparently confined to the vaginal cavity. Of the 8 cattle, 6 died or were euthanatized; only cattle with tumor apparently confined to the vaginal cavity survived.

Free access
in Journal of the American Veterinary Medical Association