What is kissing spines, and what does this common condition mean for your horse? Dr. Josh Harvey, DVM explains.
Impinging dorsal spinous process — a condition known as kissing spines — is not unusual in barrel horses, but its effects are varied. Dr. Josh Harvey, DVM, owner and founding veterinarian of Outlaw Equine in Decatur, Texas, says treatment is not always necessary, but if needed, there are a few therapies and surgical interventions that can help.
What is Kissing Spines?
According to Harvey, this impingement of the dorsal spinous processes, where these processes of the spine are pressed too close together, is generally seen in the thoracic vertebral column in the cranial and mid back.
“Sometimes we’ll see it farther up the withers, but generally, that would come from some sort of trauma,” Harvey said. “Primarily, we’ll see this condition right in the flat spot when you come down from the withers, moving toward the horse’s tail, in the flat spot—that’s the most common area, radiographically.”
Symptoms vary for this disease. Some horses can have multiple kissing spines, up to five to 10 spaces of total impingement between the dorsal spinous processes. But they don’t always show visible symptoms—often the horse can continue to do its job in the arena.
“Not every horse that has radiographic changes in their back are affected by this problem,” Harvey said. “I tell people before you operate, before you inject, before you do anything, make sure that the horse is doing some of the [characteristic] signs of kissing spines.”
The biggest indicator of kissing spines tends to be your horse bucking under saddle. Other signs include blowing off a barrel on the backside or working really stiffly—unable to bend around a turn.
“I’d say one of the most consistent things I hear about horses with kissing spines that is affecting them in the arena is that they’re inconsistent,” Harvey said. “Once day they’ll smoke the first [barrel], the next day they won’t turn the first at all. Then, it’s the second barrel.” Harvey says the most consistent thing about kissing spines symptoms is inconsistency on the barrels.
Sometimes a horse has kissing spines as a result of a traumatic event. Other times, its conformational.
“Maybe a horse flips over, with or without a saddle, and breaks or crushes its dorsal spinous processes. Generally, I can see at least precursors to kissing spines, or kissing spines already started, in 2-year-olds,” Harvey said. “If I’m doing a prepurchase on say, a baby, 2-year-old, 3-year-old, I will X-ray the back. If the dorsal spinous spaces are wide and symmetrical, I know the horse is never going to have kissing spines unless it flips over onto something. I do think we can detect this very early on in a horse’s life.”
Kissing Spines and Pre-Purchase Exams
Harvey says if he was to radiograph 10 random barrel horses, probably four of them would have some evidence of kissing spines.
In barrel horses, Harvey believes the condition is very common but emphasizes that just because a horse may show kissing spines on an X-ray doesn’t mean they have a problem. It does not always translate to performance issues.
When kissing spines shows up on a radiograph during a pre-purchase exam, Harvey also looks at other factors.
“I actually saw a horse today that failed a vet check based on kissing spines,” Harvey said. “This horse has never bucked in its life, works outstanding, does not have any palpation [pain] down its axial skeleton and has great range of motion.”
Radiographically, this horse had one static kissing spine—meaning always touching—and one dynamic kissing spine—meaning it only touches with movement.
“For this horse, I’m not going to inject it, I’m not going to operate on it, I’m not going to push for that—I’m going to let it roll,” Harvey said.
Knowing the horse’s history, the veterinarian who has worked on the horse, and the owner or the trainer, Harvey can ask questions about the horse. Depending on its history and pathognomonic signs, or lack thereof, he may pass a horse on a vet check with kissing spines.
“Symptoms are variable, and they’re very horse-dependent,” Harvey said. “Make sure you know the horse’s history [when considering buying a horse with kissing spines].”
Harvey says a horse with kissing spines may not show signs of pain when palpated. They probably will have a decreased range of motion, though.
The information from three radiographs consisting of the upper, mid and lower back generally rule whether a horse has kissing spines or not, Harvey said.
The main treatment Harvey uses is an injectable bisphosphonate solution called Osphos to reduce bone pain associated with the impingement from kissing spines. He also employs therapies such as a water walker—similar to an Aquatread—and a deep-water pool.
“The deep-water pool is the trick,” Harvey said. “If those horses can pick their core up and strengthen their core and their back, it’s just like a human. As we get older and our core gets weaker, inherently, our back gets worse. The stronger our core stays, the better our back stays. It’s the exact same in horses.”
Harvey clarifies that he doesn’t think you can prevent kissing spines from happening, since young horses and 2-year-olds often have precursors to the condition.
“I do think you can help prevent the symptoms, or at least downregulate the symptoms, by keeping your horse’s core strong,” Harvey said. “Not every horse necessarily has to swim, but exercises such as stepping over logs will build core strength, which is very important.”
The fitter and stronger your horse is, the more sound it’ll tend to be, says Harvey.
Medical treatment for kissing spines can include back injections with a number of different modalities, says Harvey.
“We use a combination of corticosteroids, ” Harvey said. “Sometimes I’ll use the stanozolol therapy, but it all boils down to getting them out of pain enough that they can fix themselves by getting their range of motion back and their core strength built back up.”
If these medical treatments are unsuccessful, Harvey says there are two surgical options currently available. One is pioneered by Dr. Cliff Honnas, DVM. It includes removing ligament, nerve and bone, which removes the impingement. That method is Harvey’s preference due to its success rate of 80 to 90 percent.
The other method is dorsal spines ligament desmotomy. While this surgery can be successful, it also can have negative reactions post-surgery and can actually worsen when looking at radiographs and the horse’s pain levels.
“You’re actually cutting the nerve— it’s almost a neurectomy of the back,” Harvey said. “I have seen some of these work, but I’ve seen more of the horses done with the Honnas method work.”
Either way, post-operative protocols are essential to helping the horse heal, says Harvey. For his clients, he prescribes 30 days of stall rest, 15 of turnout, as well as 15–21 days of rehab at his clinic.
“We start saddling at the 45-day mark,” Harvey said. “This helps your surgery site or your incision flatten out and have a better cosmetic appearance. Most of these, by 120 days, it’s hard to even tell they were even operated on.”
Kissing spines is a head-scratching condition and one that Harvey says the veterinary community is still researching.
“I still think we’re in the infancy of kissing spines and kissing spines surgery, protocols and treatments,” Harvey said.
A kissing spines diagnosis isn’t an automatic call for surgery or treatment, Harvey said.
“Just because your horse has evidence of kissing spines radiographically, if they’re not doing anything [characteristic] for kissing spines, if they’re not working bad, they’re doing their job and they seem to be doing it pain-free, they may not need to be operated on. If they are showing those negative signs and symptoms, look for medical therapies, rehab protocols and surgical interventions, if necessary,” Harvey said. “Just like anything in equine sports medicine, I remain a student of the game. I’m definitely not the end-all, be-all. We all have a long way to go, and it’s the horses that teach us the most important lessons of all.”
This article was originally published in the March 2022 issue of Barrel Horse News.