Dysmetria (from the Greek meaning poorly measured) is a lack of coordination of body movement, in which a dog seems to over or underestimate distance with the eyes or legs. In this condition, the dog is unable to judge rate, range and force of its movements. This condition refers to a lack of coordination of movement typified by the undershoot or overshoot of intended position with the leg, or eye. Simply put, dysmetria is a condition in which there is improper measuring of distance in muscular acts; the dog is unable to measure space. It is a type of ataxia. The action of overreaching or high stepping the intended location is referred to as Hypermetria (Hypometria is the underreaching of the intended location).
The cerebellum is the portion of the brain responsible for motor coordination, and if it or any of its neural pathways are damaged, dysmetria can result.
Common signs associated with dysmetria and hypermetria include
Body tremors; often more pronounced with movement
Wide leg stance
Loss of the menace response – the reflexive closing of the eyes when a finger is stabbed toward the eye
Unequal pupil size (anisocoria)
Abnormal, jerky movements