Veterinarian pulling up an injection.
Just because veterinarians can use an injection of steroids and hyaluronic acid to help a horse doesn’t always mean they should stick in a needle. Photo by Kate Bradley Byars.

Joint Injections 101: the How, What & Why

Injecting horses can seem like the miracle cure for lameness, but getting to the root of the issue and selecting the right injection blend can mean the difference between long-term success and short-lived joy.

With an advanced degree in veterinary medicine, equine doctors hold the fate of competitive horses and the hope of those horses’ owners in their hands. With a simple phrase — “We can inject.” — hope can be renewed that a horse will continue down the show road successfully.

But, is injection always the answer and does it always have the same results?

Not every equine injury or lameness problem can be fixed with a needle. To that point, not every needle is filled with the same miracle blend of steroids to reduce inflammation, hyaluronic acid to act as a lubricant and, sometimes, antibiotics to fight infection.

Brazos Valley Equine Hospital’s Joe Pluhar, DVM, understands both the owner’s side of a lameness check, as well as his part as a veterinarian. Getting to the root of the lameness is vitally important, he said. “There are two categories I place injections into: maintenance and injury,” Pluhar said. “For example, a reining horse that always stops big and isn’t getting the distance it once was may not have clinical lameness, but clearly that horse isn’t doing its job for a reason. Using a physical exam, history on a horse and lameness exam, you can figure out what you’re dealing with. In the maintenance category, we are simply trying to keep these horses performing at their very best. Sometimes, they need a little help.

“The other reason to inject joints is due to an injury. We say ‘joint injection,’ but sometimes we aren’t injecting a joint but a suspensory ligament, a tendon sheath and other areas [instead]. Hopefully, after the horse recovers from the injury, we won’t need to inject it again.”

Once diagnosed, an issue in a joint, tendon or ligament can be addressed through an injection of steroid, hyaluronic acid and/ or regenerative therapies, but the mix varies depending on the horse’s age, level of use and the budget the owner has to spend. It is a much more involved process than simply sterilizing the area and inserting the needle.

Horse owners who are aware of the process required to accurately diagnose, the options for injection and how to advocate for their horse are prepared for any eventuality. Pluhar walked through the how and why, and what to look for before opting to inject a horse for a performance issue.

The Overall Picture

In a nod to Shakespeare, to inject or not to inject is often the question when Pluhar examines a horse. The first step to answering that question is a physical exam of the animal and obtaining a thorough history from the owner.

He also looks at the circumstances surrounding the appointment.

“Sometimes it makes sense to inject and sometimes it doesn’t make any sense, be it not injecting it that day or ever. For example, a horse that is ridden once or twice a month and isn’t used very hard doesn’t necessarily need to be managed with an injection,” he said. “Instead, you can manage that horse with pain medications. “Other times, it doesn’t make sense to inject a horse at that moment because of the physical circumstances. For example, if I do a farm call and can tell a horse needs a coffin joint injection but the horse is covered in mud, I will not inject that horse that day. Injecting it then could cause issues with sterilization of the area.”

First, Pluhar seeks to understand what the horse is being used for, as well as information on feeding habits and previous health issues. He said the horse’s complete history is exceedingly important.

Vet performing a soundness exam.
Using a thorough physical examination, including flexing joints to check for lameness, as well as a detailed horse history, Dr. Joe Pluhar can best assess the situation. Photo by Kate Bradley Byars.

“Always disclose everything that has been done to a horse in the past year for a new veterinarian,” Pluhar said. “Some people use multiple veterinarians. No, I may not need to know the horse was injected five years ago, but if it was injected two weeks ago and we still have an issue, I need to know that now. “It could be the injections haven’t had time to work or we could have a larger issue. We need to know what has been done to reduce the risk to the horse and also so we can approach the problem differently so we can solve it.”

Knowing a horse’s background helps both horse and owner. Pluhar doesn’t want to continue down the same road as previously trod with the horse if that type of injection or procedure isn’t showing long-term results. From an economic standpoint, it really is not in the owner’s best interest to withhold previous treatment information.

“Maybe I’m a second opinion on this horse, and as a new veterinarian, I may think I can solve the problem in a way that the previous veterinarian already tried,” Pluhar explained. “If the owner lets the veterinarian know the situation, we can share information and hope to work on a solution that benefits the horse.”

With a younger horse in training for reining, cutting or reined cow horse, Pluhar wants even more information to make a successful diagnosis and treatment plan. He said things like nutrition, the horse’s physical fitness, its regular farrier work and its training schedule
impact his decisions. “As a horse is growing, it experiences pain in certain areas,” he explained. “Sometimes we can suggest taking care of that pain by changing the training schedule; I don’t mean to stop training but by training differently.

“A conversation I have with reiners, typically, is about young horses that have popped splints or inflammation around the splint bone in the front end. Those typically make the horse really lame because they are really painful. Those tend to come out more when a horse is worked in circles. A change in training doesn’t mean you stop loping circles, but I will talk to the client about doing some other things to keep a horse in shape but not lope as many circles.”

After riding reining horses and showing competitively in the American Quarter Horse Association (AQHA), Pluhar understands trainers are often at the mercy of the show schedule.

“My job as a veterinarian is to make that horse do its job better, and I can’t tell a client to stop a horse from doing its job just because we want to change how we inject the joints,” he said. “I inject to help the horse do its job to the best of its ability.” Pluhar’s outlook is not shared by every horse owner or veterinarian. He says that discussing joint injections can be a polarizing topic. From a group that is overly eager to inject in an effort to fix every issue to one that believes injecting a horse early in its career will create unnecessary problems down the line, Pluhar walks a line between the two sides.

“There is a risk involved every time we put a needle in a joint,” he said. “There is one argument out there that states if someone injects a horse young, then the horse will always need injections. That isn’t necessarily true. You don’t break a magic seal when you inject a joint that forces a horse to need an injection to continue working. The underlying pathology that causes a horse to need injections is going to be there, such as weakness. But it isn’t because we put a needle in there in the first place.”

When the veterinarian knows a horse’s history with injury and exercise, and understands how the horse is fed and handled regularly, the job of diagnosing the lameness issue is easier. Then, the choice of how to handle the problem is one of budget and longevity.

“Most of the time, we are really helping these horses, but no treatment plan is perfect every time without talking to the owner, the trainer and the veterinarian to get all the information about that horse at that time,” Pluhar said. “Factors outside of the joint can play a big role in, first, the decision whether to inject the joint and, second, what you’ll use [to inject in] the joint.”

Understanding the Blend

“There are as many options to put in a joint as there are grains of sand on a beach,” Pluhar said.

In order to understand what an injection can do to aid a horse in overcoming a pain-inducing lameness issue and injury or to help it perform, horse owners need to know what is being injected. And, they need to know why.

According to Pluhar, there are several options for “standard” injections with hyaluronic acid of different molecular weights. There are also several ways to stimulate regenerative healing through injection. He breaks it down.

Equine injections
Using factors like a horse’s age, nutrition, training program and level of use, as well as the desired result, Pluhar is able to
blend a steroid and a molecular weight of hyaluronic acid that best fits that horse. Photo by Kate Bradley Byars.

1. Standard Blends

For Pluhar, the “standard” injection blend is comprised of some form of hyaluronic acid, a steroid and antibiotics.

“I always put a little antibiotics in injections as an extra step to prevent infection,” he explained. “Not every veterinarian does that and there is no right or wrong answer, but it helps me sleep better at night. I also think it provides a benefit to the horse.”

The hyaluronic acid differs based on molecular weight. Without being a chemist, owners can understand that the size of the acid molecules affects horses differently — some being better for younger animals and some for older animals that are less active. “When you’re talking about different types of oil for your car, there isn’t one type that works all the time. There are different ones for different uses, and it depends on the weather and what you do with the car. It’s the same thing with hyaluronic acid,” Pluhar explained. “The acid is based on the size of the molecule — the bigger molecules are more expensive and that is due to the processing. There are varying degrees of hyaluronic acid.

“There are a lot out there and they vary drastically. You have super molecular weight hyaluronic acid all the way down to ones with smaller molecules. A mixture of small, medium and large [molecules] is less expensive. The bigger molecules take longer to break down and stay [in the joint] longer.” For horse owners, the varying weights provide options from a cost perspective. There are choices between the high end and the cheap route, and owners can talk to their veterinarians about what is the best option at that time.

Additionally, Pluhar said bigger molecules are better for younger horses or high-motion joints like fetlocks, stifles and coffin joints. The bigger molecule blends are ones that cost the owner more money, but they offer a major benefit.

“I like to use them in young horses to help make a horse’s career longer. Maybe we will spend a little more money when the horse is younger, but the hope is for it to compete a few more years,” Pluhar said.

For an older horse whose hocks may be in the fusing stage, the joints are considered low motion. Pluhar said while the joint may be causing discomfort or pain, the higher molecular weight injections are not as effective. “After the joints fuse, there is no more pain associated, so the horse can do its job without an injection. But until then, you can use a hyaluronic acid with a mix of that small, medium, large molecular weight, and it is a little less expensive.”

The other ingredient, the steroid, also offers options.

“Different steroids do better for different issues. Sometimes I choose a steroid not for the joint, but for the horse,” Pluhar explained. “If there is a horse that I am worried about metabolic syndrome with, I may not use a steroid that I know causes a laminitic event to try and be safer with the horse. For all issues, there is no 100% right answer. You have to talk to your veterinarian and come up with ideas.”

2. Regenerative

Acronyms fly around veterinary clinics like dirt flies in a reining stop. Often, an acronym’s full name isn’t known to most horse owners, but each one is indicative of another potential “miracle” fix.

Pluhar said that while regenerative medicine through the use of stem cells may seem like the poster child to cure all woes, it is by no means a veterinarian’s only option; however, understanding all options is how an owner best prioritizes a horse’s treatment.

An owner’s options include:

  • PRP – Platelet-rich plasma accelerates tissue regeneration in skin, soft tissue and bone. It is used in tendons and ligaments.
  • IRAP – Interleukin receptor antagonist protein is a natural anti-inflammatory product used in joints. It is produced from the horse’s own blood to encourage healing.
  • Pro-Stride – This is a combination of PRP and IRAP used to promote injury healing and reduce inflammation.

Pluhar said these regenerative-type medications typically start with a donor animal’s stem cells, the patient’s own stem cells or the patient’s blood. Often, those stem cells are gathered from amniotic fluid. Another option is harvesting them from the horse itself, processing the cells and re-injecting them back into the horse.

“Sometimes those processes are 15 or 20 minutes and sometimes the processes take several weeks,” Pluhar explained. “Stem cells are usually sent off to a lab that grows them, processes them and sends them back to the veterinarian.”

Cleaning the horses leg in preparation for a joint injection.
Before sticking a needle into a horse’s joint, like this horse’s hock, Pluhar and his staff ensure it is sanitized and cleaned. Contamination at the injection site can lead to infection. Photo by Kate Bradley Byars.

Pluhar typically turns to regenerative options when a horse is diagnosed with an injury and clinical lameness. Often, his first step is a standard steroid/hyaluronic acid injection, but if that doesn’t work, he will dig deeper to locate the root injury causing the issue and treat accordingly. “Say we inject a horse’s stifles and they are good for three months before you have problems again,” he explained. “Clearly, the horse has a stifle issue and clearly injections make it better, but the effect isn’t lasting as long as we want. We don’t necessarily want to put steroids in the joint every two or three months, so instead we look at doing something else like PRP, IRAP or Pro-Stride, and we don’t worry about the systemic affect of the steroid. But, you get a really nice benefit from that.”

Pluhar cautioned against owners putting all their faith — and money — behind any one particular product. The underlying issues a horse has must be addressed, even when the standard or regenerative therapies show promise.

“Stem cells are not cure-alls, but there are a lot of benefits from a pain perspective, an anti-inflammatory perspective and from a healing perspective,” he said. “With injuries, I think I get a faster healing time and a better heal to the injured structure with a regenerative therapy than if I turn the horse out. Also, we are not usually doing the regenerative therapy by itself; we are also doing shockwave or surgery or a rehab program.”

Be an Advocate

Horse owners should understand what a veterinarian is putting in the joint and why. Yes, a veterinarian is well-versed in these practices and therapies, but owners and trainers need to know the benefits and risks involved in injections. Pluhar cautions owners against not speaking up or asking questions before and after the injection process. If the horse is going home, whoever cares for it needs to be aware of potential negative reactions from the injection.

Vet finding the injection site on the horses's joint.
Pluhar takes his time to carefully find the precise point of entry to ensure success when he is injecting a horse. Joint injections are a treatment that require patience and precision. Photo by Kate Bradley Byars.

“Each veterinarian uses something a little different and there are different warning signs based on what [ingredients] they use,” he said. “The veterinarian knows what specific signs to look for based on what your horse is receiving. Post-injection, depending on the [ingredients], there are different time-off periods — from a day to several days to a few months — depending on what we inject and why.

“Some people, like me, like to keep a horse on an anti-inflammatory after the injection to protect against joint flares and also because we just put a needle in the joint and that has to be uncomfortable. So, I will put a horse on anti-inflammatories for a few days.” Injection site infection can be career ending or even life threatening to a horse. Vigilance is needed by all those charged with a horse’s care.

“If your horse is moving fine for a day, then the next day it can’t walk on the leg where it received an injection, that is a reason to get the veterinarian to look at it,” Pluhar advised. “It isn’t always the injection that is the problem, but be safe and sure. You want to get on this issue quickly. A veterinarian would rather know about it sooner than later. These things don’t happen super often, but often enough that horse owners, veterinarians and trainers have to all be on the same page and understand that, yes, the injection can do good, but there is a risk associated.”

Equine lameness can halt a horse’s training and owner’s goals, but today more than ever, there are several options to put a horse back to work. With knowledge and proper understanding of how different types of joint injections provide support, a horse has a better chance to continue down the show road.

*This story was originally published in the June 1, 2020, issue of Quarter Horse News.