Equine Neurologic Examination - What Do I Really Look For?

A description of all the manipulations that can be performed, and observations that can be made, when undertaking a neurologic examination often doesn’t give the sense of efficiency and flow that is necessary to effectively perform such examinations in practice. This presentation aims to assist the practitioner to develop a flow to the equine neurologic examination without detracting from the clinical dictum that “it is easy to look, but harder to see”; one has to know what one is looking for.

Overview

Traditionally, a detailed neurologic examination follows the collection of information on a patient’s signalment and history, an evaluation of the environment, and a complete physical examination.
However, during evaluation of a horse suspected of having a neurologic disorder, most busy practitioners include several components of a neurologic examination during the general physical examination. These should include observation of behavior, mental status, head posture, vision, pupillary light reflexes, structures of the eye, and inspection for facial symmetry, and inspection of the oral cavity. A laryngeal adductor response or slap-test should be performed and evaluation of posture and gait while walking, trotting, and turning quickly ought to be included. Inspection and palpation for muscle mass, bony integrity, and patches of sweating over the body and limbs (horse) are also easily incorporated into this examination. Tail and anal tone and reflexes can be evaluated when the rectal temperature is recorded.

Usually, this examination [Table 1] allows the practitioner to decide whether a more detailed neurologic examination, as outlined below, is required.

Sometimes enough evidence is available from this examination alone to make a fairly accurate anatomic diagnosis. Thus, a differential diagnosis and initial plan can be developed. If this cannot be done, especially if a thorough case work-up is indicated, then a complete neurologic examination should be undertaken, which will probably uncover further neurologic findings helpful to case work-up.

Signalment

The age, breed, gender, use, and value of a patient all are important considerations in the diagnosis and prognosis of many neurologic conditions. Several diseases are age-dependent. Certain diseases are associated with particular breeds. Only a few neurologic diseases depend upon gender. Certain uses to which animals are put can be associated with certain diseases, and this impacts considerably on the prognosis that accompanies the diagnosis. The value of the patient must always be kept in mind with respect to the depth of evaluation, cost of therapy, and future performance and productivity; the survival of herd mates must also be considered. [...]