In this episode of the Disease Du Jour podcast, José García-López, VMD, DACVS, DACVSMR, discussed nuchal bursitis in horses. He talked about the clinical signs, risk factors, treatment options, recovery process, and overall prognosis for the condition.
What Is Nuchal Bursitis?
Cranial nuchal bursitis occurs when the bursa of the nuchal ligament becomes inflamed. Most cases occur in athletic horses ridden with a high neck carriage, or in horses with a naturally high neck carriage such as Morgans or Tennessee Walking Horses.
“This is not an infection. This is just inflammation,” García-López said. “Every once in a while, they can become infected, but this is different from what people would call in the old days ‘poll evil.’”
This inflammation will sometimes create a noticeable growth near the horse’s poll, which will become very sensitive to palpation.
“It’s not necessarily a particularly common condition, but it’s one that in the last 15 years or so, we’re recognizing a whole lot more commonly than before,” García-López said.
Clinical Signs of Nuchal Bursitis in Horses
García-López noted there are many conditions that affect the neck, and signs can be nonspecific. Horses with nuchal bursitis will sometimes be resistant to traveling with a higher neck carriage and will prefer to keep their neck extended at shoulder-level when working under saddle. They might grind their teeth or exhibit attitude changes when ridden, especially in collection.
You might notice an asymmetry between the ears if the horse doesn’t have much of a coat or swelling on one side of the poll. In more severe cases, the horse might become resistant to haltering.
Diagnosing Nuchal Bursitis in Horses
García-López said diagnosing nuchal bursitis often involves a two-prong approach. The most common diagnostic method is ultrasound. “The bursa in a normal horse should not really be visible,” he said. “When it gets affected, then it’ll actually start filling up with tissue and fluid.” If you can see the bursa on ultrasound, it indicates the horse might have the condition.
Radiographs can also be helpful in your diagnosis, as some horses will have mineralization just dorsal to C1, which indicates the condition has been present for some time.
CT scans can also aid your diagnosis, but “the bread and butter when it comes to diagnosing these cases are ultrasound and radiographs,” García-López said.
Risk Factors for the Condition
García-López said horses in disciplines that involve a lot of neck flexion might be predisposed to the condition. He has also seen horses develop inflammation when their poll is injected without a diagnosis to warrant it. “You have to be very careful just randomly injecting this area,” he said.
When performing surgeries and collecting samples of contents from within the bursa, García-López has found a subset to be positive for Borrelia burgdorferi, one of the causative agents of Lyme disease. However, the connection between Borrelia burgdorferi and nuchal bursitis is not entirely understood, and García-López is still working on determining the significance.
Treatment for Nuchal Bursitis in Horses
If on ultrasound the fluid in the bursa is effusive without much cellularity, indicating the horse is early in the disease process, García-López said injecting an anti-inflammatory, such as a corticosteroid, can effectively reduce the inflammation. If on ultrasound the fluid is echogenic and the horse has mineralization, indicating a more chronic condition, García-López recommends surgical intervention versus medical management.
“I do worry that not only it’s [medical management] not going to help, but if then you have to go into surgical management later, those are the ones that have the highest rate of complications postoperatively,” he said.
The bursoscopy procedure is minimally invasive and involves inserting a scope inside the bursa to visualize the tissue, then debriding the inflammatory tissue with another instrument.
Rehabilitation Process
The rehabilitation process depends on the severity of the horse’s condition and the treatment they received. For horses with clear fluid within the bursa that received medical management, the rehab process typically involves a week of stall rest followed by a week or two of long-and-low work under saddle. After that, the rider can start to gradually increase rein pressure.
Horses that undergo surgery will typically be on stall rest with hand walking for two weeks. During this time, the incision site will be protected with adhesive bandages. After the two weeks, García-López recommends four more weeks of stall rest.
At six weeks postoperatively, he performs an ultrasound to see how the tissue is responding to the debridement. If the tissue is settling nicely, he puts the horse in a small paddock for another month. Then, the horse can start walking under saddle with a long and low neck carriage for another couple of weeks, with turnout still restricted to a small paddock.
Three months postoperatively, he performs another ultrasound. If it looks good, the horse can go back to more work, starting with a couple weeks long and low and gradually increasing collection. “It usually takes around 12 to 14 weeks if everything is going right for them to go back to pretty regular work,” he said.
Prognosis for Horses with Nuchal Bursitis
García-López said acute cases that receive medical management respond well to treatment and rarely have regrowth of the bursa. For surgical cases, the issue resolves in 75-82% of horses without a recurrence. The other 25% either have a recurrence of bursitis or develop draining tracts at the surgery site. “Those seem to be the horses that had severe changes and then were treated with steroid injections and then went to surgery later,” he said. Those horses sometimes require a second or third surgery. Some of the horses that develop tracts need to be euthanized because of the consistent drainage.
About Dr. José García-López
José García-López, VMD, DACVS, DACVSMR, is an Associate Professor of Large Animal Surgery at the University of Pennsylvania School of Veterinary Medicine, New Bolton Center. He received his veterinary degree from the University of Pennsylvania in 1996. He did a residency in large animal surgery with an equine sports medicine focus at Tufts Cummings-School of Veterinary Medicine from 1997 to 2000.
Related Reading
- Bad Behavior and Possible Neck Pain in Mares
- Techniques for Taking Good Neck Radiographs in Horses
- Disease Du Jour: Back Pain Management in Performance Horses
Stay in the know! Sign up for EquiManagement’s FREE weekly newsletters to get the latest equine research, disease alerts, and vet practice updates delivered straight to your inbox.