Consider this: our horses balance their weight on four legs, yet, when we ride them, we are putting weight and strain on the largest part of their bodies that do not have direct support – their backs.
If you’ve ever strained or “thrown out” your back, either from lifting a heavy object or in an accident, then you know that back pain is debilitating. If you were a horse in such discomfort, you would be cranky, not move as well, resist in the reins, tense up the back, and get “girthy”, all to alert your human that all is not as it should be.
Back soreness in horses is common, especially in performance horses such as racehorses, dressage mounts, jumpers, eventers or reining horses. In the veterinary field, it is considered a multifactorial disease with multiple causes, which makes it doubly difficult for both owner and veterinarian.
“Primary back pain does not cause lameness. Nevertheless, unmanaged asymmetry and lameness, specifically hindlimb lameness, can result in secondary back pain,” says Dr. Sarah Allendorf, a Canadian veterinarian who has worked at the Palm Beach Equine Clinic in Wellington, Florida since 2015. During her career she has been a team vet for the Venezuelan and Dominican Republic show jumping squads, as well as for the United States dressage team at the Pan American Games and World Cup Finals.
Dr. Sarah Allendorf. (Jump Media photo)
How Horses Express Back Pain
While there are no “classic” signs that are strictly diagnostic for back pain, it can present as anything from reduced performance, lack of impulsion, disunited canter, reluctance to pick up a specific lead, lack of appropriate bascule over the jump, difficulties executing advanced dressage movements, or simply resistance to being saddled and/or being labelled “girthy.” As mentioned above, if ignored, a horse in pain could become dangerous to ride by spinning, bucking, rearing, or stopping.
Your vet will examine your horse for evidence that the back is the issue. Theye will palpate the back to see if the animal is reactive and also examine things such as a reluctance to bend, extend and flex, and atrophy and/or spasm of the major muscle groups overlying the spine.
Causes of Back Pain
The first thing most owners think of when discussing causes of back pain is the dreaded kissing spines. “Kissing spines” is the colloquial term for the medical condition known as over-riding or impinging dorsal spinous processes.
As Dr. Allendorf explains, each vertebrae of the back has a vertical projection known as a dorsal spinous process and they represent the bony protuberance running along the length of the equine spine. Between each dorsal spinous process is a small gap, but in horses diagnosed with kissing spines on radiographs, there is a reduction in this space. This condition can advance to the degree that there is no gap present, the dorsal spines are in contact with each other or even overriding, and bony changes can appear (sclerosis, lysis, cyst formation etc.).
“The most important thing to remember is ‘kissing spines’ is a radiographic diagnosis and scientifically there is a poor correlation between degree of clinical signs and the severity of the radiographic abnormalities,” she says. “Meaning, horses with severe back pain may present with only mild radiographic changes whist another horse may demonstrate only mild clinical signs but have significant radiographic findings.”
While owners stress about kissing spines, according to Dr. Allendorf, it’s not the most common cause of back pain. Even though kissing spine is frequently thought of as being a major cause of back pain, it is not actually the most common cause; rather, old-fashioned muscle soreness from fatigue, spasm, or disorders of the outer epaxial muscle groups or the deeper multifidus muscles is more likely.
“Each layer of muscle overlying the spine is responsible for stabilization and support and any weakness causes reciprocal compensation by the other muscle groups leading to pain and potentially injury,” Dr. Allendorf explains. She also adds that stresses and strains from the supraspinous and sacro-iliac ligaments can also contribute to the development of back pain.
Another common origin is the development of osteoarthritis in the articular processes of the vertebral bodies (thoracic and lumbar facet joints). “Similar to any other joint in the body, the degeneration of the cartilage in these joints can cause discomfort and inflammation with secondary bony change leading to restriction of movement and even more pain,” she says. “Unfortunately, once restriction leads to pain, spasm frequently develops and can cause even more restriction, leading to weakness, disuse and atrophy. Halting this pain cycle is integral even if a proper diagnosis is not achieved.”
Back pain should be considered as a clinical diagnosis more than it is a diagnosis made by imaging such as x-rays. The clinical diagnosis of back pain is made by a thorough veterinary physical examination alongside a comprehensive history and performance evaluation. Dr. Allendorf says it’s vital to differentiate primary versus secondary back pain to properly target treatments and therapies.
Although back pain relies more on a clinical diagnosis, there are many diagnostic tools that veterinarians can use to try and find the source of back pain including radiographs, ultrasounds, and bone scans.
Treatment and Management
Regardless of the primary cause of a horse’s back pain, it’s imperative that owners and their veterinarian work together to develop a treatment plan focusing on alleviating pain, increasing strength and stability, and improving flexibility.
A common treatment is the use of NSAIDs and muscle relaxants, but owners often find their effectiveness disappointing. A more targeted approach, such as injectable corticosteroids, has proven to yield better results. “These are often the mainstay of treatment, as they are potent anti-inflammatories that can be injected ultrasound-guided into areas of concern,” says Dr. Allendorf. She adds that these areas include the articular facet joints, between the dorsal spinous process and intramuscularly within the epaxial and multifidus muscles.
Working in conjunction with the above treatments, alternate therapies are important for stopping the pain-spasm cycle. Your veterinarian might recommend therapies such as laser, shockwave, functional electrical stimulation (FES), and therapeutic ultrasound. Acupuncture has been scientifically proven to give relief to equine back pain sufferers, and some patients benefit after even one session.
Once a horse’s pain levels have diminished, your vet may also suggest rehab treatments to improve movement and flexibility, such as chiropractic manipulation, physiotherapy, and strengthening exercises, which all work synergistically with the more tradition veterinary therapies for back pain. Some of these rehabilitation techniques can be performed daily by the owner and include “carrot stretches,” “butt tucks” and ventral lifts of the abdomen.
“These exercises are aimed at stabilization and can begin slowly, where just a slight bend or little stretch is requested, and held for a short period of time,” explains Dr. Allendorf. “By utilising these drug-free treatments, back pain can often be managed well, and by using these therapies the interval between treatment can be extended.”
To sum it all up, managing your horse’s back pain is a group effort between owners, trainers, veterinarians, and therapists. “Rarely do we truly get a “cure” for back pain, but optimal outcomes can be achieved with a combination of therapies that help control pain and rehabilitation modalities to increase strength and flexibility,” adds Dr. Allendorf. “The aim of all of these treatments and therapies to is get back to work as soon as possible, because rest will slow the recovery process.”