By Dimitri Kadic MVM, DES, DACVS-LA DECVS / Equitom surgeon
Photography: Courtesy Equitom

Your horse suddenly appears “drunk”, struggling with coordination and balance. These symptoms should always prompt an immediate call to your veterinarian. One possible explanation is Wobbler Syndrome, a serious condition that will not resolve on its own.

What Is Wobbler Syndrome?

Wobbler Syndrome, also known as cervical vertebral stenotic myelopathy (CVSM), is a relatively common condition in horses, particularly in Warmbloods. Horses affected by this disease, often simply called “Wobblers”, display reduced coordination – referred to as ataxia – most noticeably in the hindquarters, giving them a swaying or staggering appearance.
Although this swaying movement is the best-known symptom, ataxia can present with a wide range of additional signs. Horses with a mild degree of ataxia often show vague and subtle abnormalities that are not immediately recognized by their owners. In this article, we will examine the causes and symptoms of ataxia, the diagnostic process, and the treatment options available for horses with Wobbler Syndrome.
Recognizing ataxia in horses

Ataxia is a neurological disorder in which the horse shows reduced coordi-nation and propriocep-tion. While it often becomes most evident in the hindquarters, it can also affect the forelimbs. The severity of ataxia is graded on a scale from 0 to 5, where grade 0 indicates a neurologically normal horse and grade 5 represents the most severe form, in which the horse is unable to rise and is paralyzed.
Horses suspected of ataxia undergo a thorough neurological examination to con-firm the suspicion and determine the severity. Although the tests are relatively simple to perform, their interpretation requires clinical expertise.
One of the typical abnormalities seen in Wobblers is delayed proprioception. For example, when a horse’s forelegs are manually crossed, it should immediately reposition them. Wobblers, however, tend to leave their legs crossed too long, showing a delayed reflex to return them to their normal stance (Figure 1). Another common sign is poor coordination when turning in small circles or moving in a figure-eight pattern: these horses fail to place their feet correctly, sometimes step on their own front feet, and make wide, staggering turns behind. Walking backward is often difficult, as they drag their toes and fail to lift their forelegs adequately.
Symptoms usually become more pronounced when the horse is asked to walk up or down a slope. Because of their hindquarter weakness, both ascending and descending are difficult, making this a simple but revealing test. Many Wobblers also have reduced tail tone. When the tail is pulled sideways as the horse walks in a straight line, affected horses lose balance much more easily than neurologically normal horses. Their hindquarters may also appear weak or unstable. In addition, reduced flexibility of the neck is frequently observed. Manual flexion of the neck can feel restricted, stiff, or even painful.

Cervical problems and subtle clinical signs

Although hindquarter abnormalities are typical, cervical problems can cause subtler manifestations. For example, some horses may show forelimb stiffness or even lameness in one or both front legs due to a cervical lesion. Orthopedic examination of such horses often reveals no abnormalities in the limbs, making the cause puzzling. In some cases, this lameness is mild and intermittent, present on one day and absent the next. Horses with these signs should always undergo a detailed cervical examination.
In performance horses, subtle signs include abnormal canter patterns. Horses with ataxia often show cross-canter or, in more severe cases, gallop with a bunny-hopping motion resembling a rabbit. Showjumpers with mild ataxia sometimes jump excessively high in an effort to clear obstacles safely, compensating for poor coordination. In the field, these horses may struggle to stop efficiently because of weak hindquarters, leading to stumbling or even falling. At this stage, they are unsafe to ride. Experienced riders may notice performance issues earlier than they become visible to the veterinarian, making it essential for vets to listen carefully to rider observations...

CLICK HERE TO READ THE COMPLETE ARTICLE IN THE ONLINE EDITION OF BREEDING NEWS