Incoordination of the Legs in Dogs

Dysmetria (an undershoot or overshoot of the intended position, resulting in a goose-stepping movement) and hypermetria (cerebellar dysfunction where the movement of the legs go beyond the intended goal) are types of ataxia (loss of control of bodily movements) dealing specifically with the legs. Dysmetria is more about the dog’s inability to judge it’s movements while hypermetria is overreaching of the intended location. While this can affect a variety of breeds, Kerry Blue Terriers, Chinese Crested dogs, and Coton du Tulear dogs have the capacity for dysmetria/hypermetria to develop into more severe motor problems.

Ataxia refers to the loss of control of bodily movements. Types of ataxia include dysmetria, in which the dog cannot accurately gauge distance or fully understand the force of their movements, hypermetria, in which the dog overreaches their intended location, and hypometria, in which the dog falls short of their intended location.

• Loss of balance when making sudden turns
• Dizzy spells caused by sudden head movements
• Nystagmus (twitching of the eyes) which is usually up and down, but can also be side to side or circular
• Appearance of seizure or stroke
• Tremors
• Banging of the nose into food
• Stiffness of limbs
• Broad stance
• Swaying from side to side
• Difficulty maintaining balance
• Titubation (shaking of the trunk of the head while sitting or standing)
• Dilation of pupils

Types

Ataxia refers to a loss of bodily control. There are a few types of ataxia, including hypermetria and dysmetria.

• Hypermetria:Hypermetria is when the dog is overreaching for their intended location.
• Hypometria: Hypometria is the opposite of hypermetric, in which the dog falls short of their intended location.
• Dysmetria: Dysmetria refers to the dog’s inability to judge distance or fully understand the force of their movements.

Ataxia is typically caused by neurological diseases. Some of the neurological diseases associated with the cerebellum that cause dysmetria and hypermetria include:

• Cerebellar cortical abiotrophy (a genetic neurological disease that develops when neurons in the cerebellum begin to die)
• Cerebellar malformation (a malformation of the cerebellum)
• Dandy-Walker syndrome (a congenital brain malformation involving the cerebellum and fluid-filled areas surrounding the cerebellum)
• Foramen magnum-associated malformations (malformations in the foramen magnum, a hole in the base of the skull where the spinal cord passes through)
• Brain tumors (primary and secondary)
• Paraneoplastic cerebellar degeneration (a rare nonmetastatic complication of a carcinoma)
• Rickettsial disease (disease caused by bacteria of the Rickettsia species)
• Protozoal disease (disease caused by parasites in the Protozoa kingdom)
• Trauma

Your veterinarian will want to know your dog’s health history and will have you describe the symptoms and their progression. Once this has been established, your veterinarian may complete a variety of tests, including:

• Physical exam
• Orthopedic exam (done by observing how the dog walks)
• Neurological exam

Your veterinarian will be looking for abnormal gait. This can occur as short steps, improper load distribution (typically more weight is carried on the forelimbs, though in some cases the dog will carry load on its back limbs), and weakened gait.

In addition to these tests, other tests will be used depending on accompanying symptoms that are indicative of the underlying cause of the ataxia.

Depending on underlying causes, your dog may need to be hospitalized so that possible treatment options can be completed. Treatment will depend on the underlying cause and can vary from treatments for carcinomas to rare neurologic disorders. In some small dog breeds it’s possible that the abnormal gait is just a characteristic of their genetic makeup. Because many cases of ataxia result from cerebellar problems, there may be no treatments available for the underlying cause of the condition.

Much like treatment, recovery and management depend largely on the underlying cause of the disease. There are a number of possible causes for ataxia, many of which deal with the cerebellum. Treatment and prognosis depend largely on the underlying cause of the ataxia, though some cerebellar causes are untreatable and have a grim prognosis. In most cases, continual follow-up appointments for neurological exams will be required. In some cases, the prognosis may be grim.