The complexities of diagnosing and treating cervical neck problems in horses are laid bare in a just-published review.
Melinda Story and her colleagues at Colorado State University, writing in the journal Animals, noted that neck pain and dysfunction in horses is becoming an increasingly important topic among riders, trainers and veterinarians.
Some horses with cervical neck issues may show little more than a subtle performance decline, while others may show dramatic, dangerous behavior, they said.
“It is important to recognize how to carefully evaluate the horse in an effort to understand the different types of pain that may be contributing to the different behaviors.”
Recognizing that there are many diagnostic options, as well as several treatment choices, is important, they said.
Understanding and distinguishing the different types of neck pain is a starting point to understanding how the clinical signs can vary so greatly.
“There are many steps needed to systematically evaluate the various tissues of the cervical spine to determine which components are contributing to cervical pain and dysfunction.”
Bone structures, soft tissues and the central and the peripheral nervous system may all play a role in these various clinical presentations.
After a clinical evaluation, several imaging methods may be employed to help identify the affected tissue or structures as possible sources of pain. Each imaging method, such as x-ray and ultrasound, has its strengths and limitations, and a clear diagnosis may not be readily obtained.
The review team said there were multiple treatment options. “Each must be carefully chosen for an individual horse,” they said.
Subtle signs can be important
“In horses presented for declining performance or behavioral issues, it is of paramount importance to first determine whether the horse may be experiencing pain, and possibly what type of pain.
“On the surface, this seems like an easy task; however, the diagnosis of cervical pain is not always straightforward, and the clinician must consider all available information: history, observation, static palpation, motion palpation and dynamic evaluation.
The authors stressed the importance of looking for and interpreting any signs, even the most subtle ones, of muscle discomfort.
“While this seems straightforward, the interpretation of the examination, and fitting it to the clinical picture is complex.”
The authors described the wide spectrum of clinical signs associated with cervical pain and dysfunction.
“Horses with cervical pain display obvious discomfort associated with palpation or active neck movements in work, as well as during stretching exercises or even daily routines.
“In contrast, horses that have cervical dysfunction, without overt pain, may display more subtle signs of avoidance, it is possible for horses to display combined signs of pain and dysfunction.”
Affected horses in either category may have a history of a general decline in performance, neck pain and stiffness, an unwillingness to work on the bit, subtle hind limb gait abnormalities and lack of impulsion, and possibly forelimb lameness.
“Horses with cervical dysfunction are often simply stiff or unwilling to be soft in the bend of their neck and body, may have difficulty with performing certain movements such as smaller circles, or they may pull against the reins or start tossing their head.”
While some horses are seen by a veterinarian over a decline in performance or resisting work, others are more dramatic in their presentation.
“These horses may stop and refuse to go forward and may even rear and flip over backwards if the rider continues to ask in more forceful ways.”
An unexplained change in behavior is another common clinical sign recognized in horses with cervical pain or dysfunction, they said.
“These horses display sudden onset of spooking within familiar surroundings or they are reported to act fearful. Riders and trainers may not always recognize these subtle behavioral changes, which may only be identified while acquiring a detailed history or be seen during on-site or ridden examinations.
“It is also possible for affected horses to develop apparent hypersensitivity whereby they resist being saddled, brushed, or even touched. Sometimes these horses even avoid the typical social greeting at the stall door or being caught.”
Occasionally, horses are seen by a vet for concerns that seem unrelated to cervical pain, such as weight loss seen in horses with cervical pain that precludes them from reaching food on the ground or requires twisting their head to eat from a feeder.
“With many different clinical presentations, the practitioner must use detailed observation and all other forms of clinical information available to arrive at a diagnosis of neck pain and dysfunction.”
Different disease processes
Their review goes on to traverse current knowledge on the different disease processes known to cause cervical pain and dysfunction, as well as diagnostic approaches and treatment strategies.
“Improving the knowledge in these areas will ideally help to return horses to a state of well-being that can be maintained over time and through the rigors of their job or athletic endeavors.”
The authors said it is becoming increasingly recognized that many horses seen by vets for poor performance have underlying cervical lesions that result in pain syndromes and an inability to meet athletic demands.
“However, understanding exactly which structures within the cervical region are affected remains difficult and a potential source of frustration.”
Unfortunately, diagnostic imaging often fails to fully explain the underlying disease process.
Even human physicians, after verbal feedback from patients, can struggle to identify the source of neck pain even after employing advanced imaging methods and other diagnostic techniques.
“This underscores the challenges that we face in equine practice to understand and diagnose this frustrating and potentially debilitating condition in horses.”
The review team, noting a lack of peer-reviewed literature relating to horses on this topic, described their paper as a hybrid of a literature review combined with the authors’ clinical and research experience.
They discuss pain mechanisms, cervical dysfunction, bone-related sources of cervical issues, soft tissue issues and dysfunction, and problems relating to the nervous system.
They then traverse diagnostic imaging options, and treatments, ranging from drugs, to chiropractic, therapeutic exercise and acupuncture, to mesotherapy, electrotherapy, shockwave treatment, and the use of elastic therapeutic tape.
Surgical options include arthroscopy and cervical vertebral stabilisation.
“As information is being added to the literature at a rapid rate, it is important for veterinarians presented with these types of cases, to stay abreast of new material. It is the authors’ opinion that as more and more practitioners and riders begin to recognize the complexity of these cases, we can work together to ultimately improve the clinical outcome of these challenging cases.”
The review team comprised Story, Kevin Haussler, Yvette Nout-Lomas, Tawfik Aboellail, Christopher Kawcak, Myra Barrett, David Frisbie and Wayne McIlwraith, all with the College of Veterinary Medicine and Biomedical Science at Colorado State University.
Story, M.R.; Haussler, K.K.; Nout-Lomas, Y.S.; Aboellail, T.A.; Kawcak, C.E.; Barrett, M.F.; Frisbie, D.D.; McIlwraith, C.W. Equine Cervical Pain and Dysfunction: Pathology, Diagnosis and Treatment. Animals 2021, 11, 422. https://doi.org/10.3390/ani11020422