Gait – an introduction

37 Gait – an introduction

Weakness (paresis) or paralysis, ataxia, and lameness are the most commonly observed alterations in gait.


A chain of synapsing neurons is called a pathway. A pathway in the CNS may be known as a tract, fasciculus, peduncle, or lemniscus. Small bundles of neurons in the PNS are called fascicles which combine to create nerves.

Descending tracts from the brain transmit the impulses which make the animal move. The impulses gain access to the muscles via nerves.

Differentiating the cause of paralysis requires examination of the limb’s nerve function: muscle tone and reflexes. If the tone and the reflexes are intact, present, normal (2+) or increased (3+, 4+) on examination it means that those nerves, and the spinal cord segments of their origin, are functioning and are not responsible for the weakness or paralysis.

Fantastic! A functioning reflex arc means a whole chunk of the nervous system works! The cause of the weakness therefore lies in the descending tracts cranial to the weak or paralysed limb.

But…if the tone and reflexes are reduced (1+) or absent (0) on examination it means that those reflex arcs do not work and somewhere in that reflex pathway is to be found the lesion causing weak or paralysed limbs (Fig. 37.1) (see p 20, Table 2.3).

Sep 3, 2016 | Posted by in SMALL ANIMAL | Comments Off on Gait – an introduction

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