Electroneurographic examination of the ulnar and radial nerves in the dog: reference values, biological variation and reproducibility.

The radial and ulnar nerves were examined electrophysiologically in 90 normal dogs. In 66 of these dogs, aged between one and eight years, the reference values were established for 27 variables. Multicomponent sensory nerve action potentials were encountered at the proximal recording site in the ulnar nerve in 68 per cent of the dogs in the reference group and in the radial nerve in 26 per cent. Differences between the sexes were not significant, nor were differences between two breeds of similar body size. There were no significant age related differences between the ages of one and eight years. Limb length, measured as the distance between sensory stimulation site (digits) and proximal recording site (elbow), was found to have a significant effect on the velocity, amplitude, number of positive peaks and duration of the nerve action potentials. The variation in results of repeated measurements of velocities ranged from 0 to 11 per cent. The relative error in velocities due to errors in measurement of distance and latency ranged from 1 to 12 per cent.