What are they?
Joint injections are used to relieve pain and inflammation within the joint. For the most part, they are composed of a corticosteroid and hyaluronic acid. The corticosteroid acts by decreasing the inflammation and pain associated with it. The hyaluronic acid works by lubricating the joint and thereby decreasing the level of inflammation. Hyaluronic acid is the main component of joint fluid and acts as a viscous lubricant. When a joint becomes inflamed, the fluid degrades and the level of viscosity and lubrication within the joint decreases leading to more inflammation. Therefore, the reason hyaluronic acid is injected with the steroid is to help replace what has been lost or degraded.
Conventional joint injections are the most effective and most affordable option however biologiques are another very good option.
Biologics such as Irap or PRP are also used as joint injections. Irap (interleukin 1 receptor antagonist protein) is used to decrease inflammation within the joint but is much more expensive than conventional joint injections. PRP (platelet rich protein) is also used but to a lesser extent than conventional injections and Irap injections. It seems to be less effective as a joint injections as opposed to its very popular use in soft tissue injury healing. Both are created by drawing blood from your horse that undergoes processing which isolates certain antiinflammatory components to be reinjected in the joint(s) of interest.
Are they bad?
When people are told by their vet that injections are recommended either they do it or they are afraid to do it and in my experience in both cases its because they care for their horse.
The most common fears I hear from clients who are resistant to the idea is that they have heard that injections are bad for the long term health of the joint and that if you do it once you have to keep doing it. The thing is, if your horse truly has a sustained amount of inflammation in his or her joint that goes untreated, there are definitely going to be long term consequences in not only the health of the joint but in his or her overall health. Sustained inflammation leads to joint damage and even arthritis not to mention added stress on the rest of the body due to compensation for lameness. In fact I have many patients that have had their joint(s) previously injected either by me or another veterinarian in the past that do not require regular injections. Of the horses that do require a regular injections, I don't necessarily see the frequency increase over time. I think a couple reasons horses are being injected more today than maybe in years past are differences in genetics, training age, human perspective and level of performance.
As a veterinarian, my concerns with joint injections are making sure they are truly needed and making clients aware of the possible immediate risks of injections. In rare instances horses can have a reaction to the material being injected or can develop infection in the joint, all of which happen within days of injection and can be life threatening. Luckily this is a very rare occurrence in practice and I'm very fortunate to not have experienced it first hand.
Are they right for my horse?
I know this is a question that many horse owners struggle with when trying to balance performance and comfort of their horse with long term health and financial concerns. So, how do you know if injections should be considered for your horse: listen to your vet and your horse. Many horse owners will notice that their horse just isn't performing quite right and that something has changed either gradually or acutely such as not wanting to use their hind end as well, maybe feeling feeling a bit off or short strided in one or more limbs, maybe a bit sore in the lower back, etc. Its usually something along those lines that gets the owner to call the vet and have an exam. Once a veterinarian has done a thorough moving exam and likely some imaging such as radiographs he or she then provides recommendations. Some of the things your vet may notice that would indicate or warrant joint injections could be:
Gait symmetry or lameness that can range from quite mild to severe (an irregularity or unevenness in gait in the hind or front end or both depending on the limb or limbs affected)
Positive response to flexions corresponding to the joint in question (their gait will become more uneven and/or lameness will become more evident when that joint is flexed)
Joint effusion may or may not be noted upon examination (this can be seen visually in some joints and palpated indication there is inflammation in the given joint(s))
Nerve and or joint blocks resulting in resolution of lameness or positive flexion (your vet will inject a numbing agent similar to lidocaine into the nerve or associated joint to help more specifically isolate the area the lameness is coming from to better guide what should be imaged and what possible treatments such as injections are indicated)
Imaging such as radiographs that show irregularities in the affected joint(s)
After having listened to the history my client has provided, taking in all my observations during the examination and performing any diagnostics that are indicated to isolate the source...I then provide my recommendations. More often than not, my recommendations will come along with shoeing/trimming recommendations to help with whatever issue has been diagnosed. More often than not, the need for injections is a side effect of imperfect conformation, imbalances in the foot, wrong shoe type, etc. all of which can generally be aided with some podiatry changes if necessary for a more holistic approach that may save you from having to have your horse injected as often (or at all). Alternative therapies such as IV or IM injectables (such as legend or adequan), acupuncture or shockwave therapy can be very effective either in place of injections (in some cases) or in combination for a more “whole horse” approach.
By Dr. Caili Fulgoni D.V.M.
So many horses are being injected repeatedly and/or going around in some form of discomfort that could be resolved or at least substantially reduced by looking more closely at their hoof balance, alignment and shoeing. Coffin joint pain along with navicular pain and pastern pain are the most common issues we treat in the front feet. Traditional injections using corticosteroid and hyaluronic acid, biologicals such as IRAP and modalities such as shockwave and acupuncture can be very effective and are even necessary at times, but you should consider why it is your horse is having an issue with pain and inflammation in that particular joint, tendon, ligament or bursa in the first place. There are cases in which a horse may already have arthritis and injections may be required at intervals to help manage the joint, but often horses are being treated every 6-12 months or more frequently before the formation of visible arthritis for joint inflammation or pain. Being diligent about the alignment of your horse's foot you may be able to avoid any joint injections, nsaids or shockwave or at least reduce the frequency at which its required.
Hoof Pastern Alignment:
The majority of front foot lameness issues have to do with alignment irregularities. Sometimes these irregularities can be very subtle radiographically and are not evident by simply looking at the foot. In other cases, horses may have a very visible conformational alignment issue but the key to dealing with it may be a lot different than you thought which is why radiographs and proper interpretation are essential. Broken back hoof pastern axis with long toe and low heel is the most common alignment issue we see in the front foot and leads to joint inflammation, navicular issues and soft tissue injuries, all of which result in lameness. The issue is regularly overlooked, especially in cases that are not obvious without radiographs. Unfortunately, when managing these cases people often let the horses grow more heel to compensate but that generally just causes the heels to become underrun leading to even more issues. Another common issue is the club footed conformation. It is a type of angular limb deformity that begins when the horse is a foal and is caused by having contracted deep digital flexor tendons. These horses tend to be broken forward and grow a steep hoof with a lot of heel. The natural response for most people is to take as much heel off as they can to try and get the foot to appear more normal, improve weight distribution and improve the broken forward nature of the foot. However, I have seen too many occasions when the heels were trimmed aggressively to achieve alignment and though it did improve the alignment of the foot it also led to injury of the deep digital flexor tendon due to the tension created by the angle change. In some cases the increased tension/stretching on the DDFT causes it to contract further and pull on the coffin bone causing it to rotate creating laminitis. In these cases it is important to keep the horses on a short trimming/shoeing cycle no longer than 6 weeks. Small and continuous change is the only way to get the tendon to gradually give and adjust to the angle changes and over time. If the horse is on a long cycle and a great deal of hoof needs to be trimmed away then a wedge should be placed to help ease the tension on the tendon and frequent gradual changes should be made moving forward with gradual reduction of the wedge.
Horses feet can be quite deceiving by external appearance compared to their radiographic appearance. For example, it is assumed by most horse owners that a horse with very steep pasterns that grow quite a bit of heel ( club foot appearance) would never need heel elevation, but looks can be very deceiving. In fact, there are a great deal of these club footed looking horses that are actually broken back at the coffin joint and who suffer from a great deal of pressure/impingement of the dorsal aspect of the coffin joint. These horses respond very well to a good balanced trim to remove all excess hoof and some form of a heel wedge.
Medial to Lateral Imbalance:
Medial to lateral balance or imbalance refers to the symmetry of the hoof comparing the inside (medial) half to the outside (lateral) half. Radiographs allow you to compare hoof length from side to side with differences in joints space form the medial to lateral aspects of the coffin and pastern joints. Radiographs also give you the ability to assess the symmetry of each pastern bone and how it relates to the length of the hoof from side to side so you can have the farrier make adjustments if needed. Any imbalance can lead to joint inflammation/arthritis and serious soft tissue injuries as well. You can look at the hoof in person and find that one side of the hoof is longer than the other and have your farrier trim the horse so that its even, and you may be right...however that might be the way the horse needs to grow in order to compensate for some bone asymmetry in the pastern and maintain proper joint space balance. The bottom line again is that radiographs are necessary to know what's really going on inside the foot and if any changes in the trim need to be made.
Here is what you need to do:
Maintaining proper foot balance and alignment is crucial to the soundness of your horse over time. Though it has the potential to save you a great deal of money and time by helping to prevent the need for medical treatment, it does require commitment. Every horse should have a hoof balance and alignment consultation, not only to help those who have had soundness issues but also preventatively in sound horses.
Please call text or email with any questions and look for Dr. Fulgoni’s next post that talks about shoes and how she can help you figure out what shoe type might be right for your horse.