Because movement and motor behaviors are easily observed in domestic animals, the veterinary neurologic exam is tailored toward testing proprioception and reflex arcs. Human physicians, however, can also evaluate a patient’s emotional and cognitive function because people have the added benefit of speech to aid the investigation. In first year, we practiced initiating the patellar reflex and flexor reflexes, using those little orange rubber hammers to elicit an unconscious kick from our attention-craving beagle. We also evaluated whether the beagles knew where their limbs were in space, by knuckling over their paw as they were standing, to see if they replaced it in the proper position quickly. Later, once we learned the cranial nerves, we practiced individually evaluating their function using tests like the pupillary light response and palpebral reflex.
During our second year clinical skills course, we went through a neurologic exam on a horse. Much of the cranial nerve testing was the same: test for smell by hiding a cookie in one hand, test for sight by walking the horse through a maze, evaluate the menace response. Our teaching mare was surprisingly cool with having her tongue pulled out for inspection of its muscle tone, and so was slow to pull her tongue back in, an example of a normal horse having an abnormal test response. I really enjoyed the slap test, which doesn’t have much clinical value but illustrates a connection between innervation of neck muscles and the larynx: when you slap the horse’s neck just over the shoulder, you feel a jump in the contralateral laryngeal muscles, as they contract. Kinda surprising and illogical, but cool.
We ended the exam by evaluating the horse’s gait as she walked in a line then in a circle, with her tail pulled to one side or with her head held up, then backed up in a line. It was really interesting to note the species differences in what senses they rely on, and how veterinarians have to tailor neuro exams to their patients.