SI vs hock injections?

[leheath]

My mare is nearly 10yo and I’ve had her for 5 years. She was just started before I bought her and she is worked regularly (3-4x/week), but not particularly hard (jumps an average of 3x/month, rest is hacking or dressage) and she has been fairly lightly competed (3-4 competitions/year) in both dressage and eventing (training and beginner novice level).

She has had what looks like a “hunters bump” since I’ve owned her. Occasionally it shows sensitivity when palpated. She toes out on the right hind. This is less noticeable with good trimming and better dressage work, but it gets more obviously pretty quickly if either of those 2 things are lacking (neither are currently). She occasionally loses the lead behind when cantering turns to the right, but this may be because I am not symmetrical and tend to put my weight too much to the right while riding (but working on improving in this area). She is often “tight” in her back when I get on - head popping up, back and stride shortened, not keen on going forward. This improves significantly as the ride progresses. Other than these “issues” she is sound both in the dressage ring and when jumping.

2 months ago I had a new to me (but well respected by the barn I am boarding at, that I moved to 7 months ago) chiropractor assess her more for general good health/maintenance than because of any significant problem. She found some sensitivity in the right hock and some left front compensation. Had vet out and she passed flexions tests on all 4 legs. Had x-rays done on right hock and left front and both were completely clean.

Had chiropractor out again today to see if anything was better or worse. Still sensitive on right hock and SI is more sensitive to palpitation. Suggests getting vet out to consider SI or hock injections (depending on which one we think is causing the other). I am not a big fan of injecting anything unless I have reasonable confidence it will result in significant improvements for the horse - in 35+ years of horse owning, riding, and competing, I’ve never had one that “needed” joint injections until they were very close to retirement (e.g. in their 20s!).

Now the questions! Has anyone had hock injections be useful if no joint changes were seen on an x-ray and flexions tests didn’t highlight problems? If hock x-rays and flexions are “clean”, is the root cause more likely to be the SI joint? Is imaging in this area practical or valuable? How can I tell the difference between soft tissue vs joint related issues, before I allow a vet to stick a needle into a joint? Is something more systemic like Adequan effective for SI issues? We’ve also been increasing our collection work in the dressage arena recently. Could all this just be work-related soreness rather than something that needs vet attention?

Thanks in advance for any thoughts you might offer on these questions!

[skipollo]

So my horse is similar in that when out of work and when having hind end issues, he gets that prominent pointy bump over his hind end. When he’s up to date with his maintenance and in shape, it’s not very noticeable.

His hocks xray “okay.” My vet says his xrays look average for a 12yo OTTB in full work, they don’t look perfect but don’t look bad either. HOWEVER. He presents poorly, flexes poorly, and develops all over hind end soreness if I don’t keep up with his maintenance (injections.) He gets both hocks and both stifles done yearly, and if he goes too long, his SI will become sore. When we first discovered he was having all these issues (he began stopping XC which he NEVER did before), my vets said that SI pain is secondary pain from compensating from pain elsewhere most of the time. Is that a guarantee 100% of the time? No, but that’s the most common cause. If I stay on top of his hocks/stifles, then his SI stays calm and pain free.

I’ve never used Adequan but have used Pentosan with no success. Adequan is a totally different drug though, so don’t let that dissuade you from trying it. A lot of people swear by it. We opted to go right to joint injections because he was so uncomfortable.

Every horse is different, so TBH I would call your vet to see what they think. SI injections are a little more involved than hocks because they’re ultrasound guided. The needles are long, like almost a foot long :eek: We had to haul my horse to the clinic to get his SI done but hocks/stifles could be done in the barn aisle at home.

We did stifles, then hocks, then SI, all over a span of maybe five months from 2017-2018.

[Willesdon]

Do you always ride on the same surface? Is the horse better or worse on different surfaces?

[artisticgold]

Interesting topic as I just got back a 14 year old gelding who was one of my foals. He too has a hunter bump when neither parent had that, very poor top line, and was visibly off when I got him. He toes out on the right hind and it seems weak, going to the left, he usually picks up the counter canter, or the left lead in front but not behind. I’m wondering the same thing if it’s hocks, stifles or SI. I’d welcome more comments in the original poster’s thread.

[BayBondGirl]

I’ll be following this with interest.

My 20 year old flexed a bit sore on hocks, more so one than the other. X-rays came out surprisingly clean for her age and resume, we decided to inject hocks anyway. It made a major difference right away, but after ~6 months she was declining back into some stiffness. She warms up nicely out of it for the most part, but it definitely makes me think the hocks may not be THE issue here, even if that is what she flexed positive on. Vet didn’t feel that it was SI or stifles but SI would be my next avenue of pursuit.

[BoyleHeightsKid]

Work your way up from the bottom and start with the feet. If hind foot balance is off it’s going to cause soreness higher up. Feet with bull nosed appearance, long toes/low heels and medial/lateral imbalance, thin soles etc.

Here’s a great topic started a while back about SI injections. Lots of good info and experiences here:
https://www.chronofhorse.com/forum/f…pdate-post-102

[leheath]

@Willesdon

Do you always ride on the same surface? Is the horse better or worse on different surfaces?

We ride in a variety of surface with no appreciable differences between them. If anything, she might be slightly better on harder surfaces but we are typically conditioning or cross country schooling on those surfaces so less tight turns or collection.

[Elouise]

In my general experience (adult ammy), if I see a horse toe out behind…I question stifles. If I see a horse swap off the lead behind…I question stifles.
Have someone watch the horse go…does the stifle appear to be ‘pointing out’ as the horse goes. Then I really question stifles.

[CindyCRNA]

I am having the same issue with my guy. We have done SI injections, stifle and hock injections. We are looking into other causes. As a medical person, I can tell you xrays don’t necessarily correlate with physical presentation. Some folks can have significant arthritic changes and have no pain. Others can have mild changes but are in constant pain. My guys stifles looked fine on xray but when the vet inserted the needle, copious thin fluid poured out indicating inflamation. Joints can hurt before changes are apparent on radiograph.

[TheHunterKid90]

Yes, I have had a horse respond to injections that xrayed quite clean.
In this situation I would be looking more at stifles with the falling out of lead. I know you mention that you aren’t always centered and balanced but if you have to sit perfect to keep your horse in lead, I think your horse has some issues, not just you.

[leheath]

@BoyleHeightsKid

Work your way up from the bottom and start with the feet. If hind foot balance is off it’s going to cause soreness higher up. Feet with bull nosed appearance, long toes/low heels and medial/lateral imbalance, thin soles etc.

Here’s a great topic started a while back about SI injections. Lots of good info and experiences here:
https://www.chronofhorse.com/forum/f…pdate-post-102

Thank you for the link - that was a very useful thread. No idea why it didn’t come up when I searched!?

[BoyleHeightsKid]

@leheath

Thank you for the link - that was a very useful thread. No idea why it didn’t come up when I searched!?

It was tough to find for some reason… so when I finally found it a while back, I bookmarked it

[merrygoround]

OP-You have an essentially sound 10 yo horse. She flexes clean (not always reliable) but radiographs clean. The veterinarian sees nothing else.

Yet you have a chiropractor who sees this’nthat.

I would quietly continue to keep my horse as fit as possible. And save your money.

[Atlas_Shrugged]

I find that when I have hock injections on my horse, I wind up having SI done shortly thereafter- or vice versa - For as I tend to one problem, the other can become more pronounced. Have you tried Robaxin for the back? I have a giant WB and had the hardest time finding a saddle that would not interfere with his shoulder (he’s a hunter, from a dressage breeder)- finally had to buy him a Stubben that did the trick - amazing how he stopped being ‘girthy’ once the shoulder was freed up. I realize this is a dressage forum, so maybe it isn’t an issue.

[IPEsq]

So I have learned the hard way that SI problems do not always come from issues in the lower limb. My late horse had minor changes in the SI on rectal ultrasound. Didn’t have a hunter’s bump or anything suggesting acute SI injury. Had chronic soreness in the area and benefited greatly from SI injections. Less often we also injected his hocks. He had some mild OA in the hocks but while it hadn’t progressed according to Xray, sometimes there would be inflammation which was confirmed by the quality of the joint fluid when we injected and his response to injections. On necropsy, the SI joints were described as having evidence of non-union with dull red-brown corrugated and eroded articular surfaces. Therefore, SI joint disease can be a primary pathology and the more clinically significant finding. It’s not just an area that gets sore from compensation for a distal limb problem. That said, although he had some periodic inflammation the hocks and mild OA, he flexed 1/5 on rare occasion and usually flexed clean. We flexed him many, many times in his life chasing the problems that were higher up. He showed very specific symptoms when his hocks were bothering him that I could differentiate from the SI type behaviors.

Based on your description of performance behaviors and the evidence of SI issues, I’d probably start with the SI and then see if the hock calms down. But if not, you might need to treat both now but maybe the hock injections would not need to be repeated if you stay on top of the SI issue and fitness.

Imaging the SI can be a crap shoot (see above). It is just hard to look at much of the area. When I did the rectal ultrasound I was basically looking to rule out lumbo-sacral disc disease and things like that.

[OneTwoMany]

@leheath

Now the questions! Has anyone had hock injections be useful if no joint changes were seen on an x-ray and flexions tests didn’t highlight problems?

The short answer is"yes".

Stepping back for a moment, it might be useful to think about the progression of arthritis.

Every time a horse walks, exercises, or even just moves around, their joints experience minute levels of stress, compression, etc. In a normal environment, the body responds and the “wear and tear” resulting from joint use is repaired. However, sometimes the body is unable to repair itself fast enough. This can be due to different reasons such as genetic predisposition, trauma, increased levels of exercise, aging, etc. Conformation can also play a role. If the body is unable to make the necessary repairs, inflammation levels can increase, become chronic, and certain structures within the joint could begin to be compromised. The synovial fluid can thin and that can result in less lubrication within the joint capsule. Collegan fibers can thin, weaken or become damaged. The cartilage can begin to break down and the cycle builds. By the time bony changes are evident on a radiograph, the damage is irreversible and one is dealing with a condition that must be managed, with the goal being to slow down the disease and control pain.

On the other hand, if the joint inflammation is caught early enough, (before there is irreversible damage to key structures) joint injections, can be used to help interrupt the cycle of inflammation and give the joint a chance to re-establish a more healthy environment. This is why some owners won’t wait for a “bad radiograph” before they inject. Instead they and their vet will be guided by the performance of the horse, lameness evaluations and physical evidence of joint inflammation such as stiffness or sensitivity to palpation

Every situation is unique, but if a horse in our barn was having trouble holding a lead behind, I’d be concerned about the possibility (likelihood?) of joint pain. Our course of action would be to have our lameness specialist (we love our GP, but we use a specialist for lameness issues) in as soon as we could schedule a time. He would do a physical exam, noting any inflammation or sensitive areas followed by a lameness evaluation which would include trotting on different surfaces both in a straight line and on a small circle, lunging on a larger circle, observing the horse while it was ridden, flexions, watching video that demonstrate the horse having trouble holding the lead etc. When the vet identified the joint(s) that appear to be causing the issues, he would take radiographs. 98% of the time, the rads are clean, meaning we caught the problem early and we are going to be able to focus on breaking the inflammation cycle rather than the more gloomy topic of how to manage a joint with permanent changes.

[leheath]

@OneTwoMany Thank you for the helpful response - I hadn’t really thought of the relationship between arthritis development and injections in quite that way before. Can (or anyone else!) comment on the the efficacy of direct joint injections vs something like Adequan? Might Adequan be a better choice if we are struggling to differentiate between hock and SI issues? Are there any “reliable” ways to determine if a problem is hocks vs stifles vs SI?

@IPEsq thank you for sharing your experience. What were the specific indicators your horse gave when his hocks, rather than the SI, were the problem?

I have scheduled the vet to come out in a week so we will see what he thinks. While I tend to blame everything on my poor riding skills, I don’t think those skills are getting worse, while the horse has definitely developed “issues” that weren’t happening previously (stopping at fences that she previously wouldn’t have stopped at and she never use to lose the lead behind even in really tight right turns when I was way less aware of my own imbalances).

@Atlas Shrugged can you elaborate on the use of Robaxin? In the US that’s requires a prescription for humans, but I get it OTC for my back when I’m home in Canada. Do you get it through your vet or use the human version for a horse? All saddles have very recently been checked by a competent fitter, so I’m pretty confident they aren’t the problem, but I know how I feel when I need Robaxin, so if she feels like that, it could explain a lot! :eek:

[Obsidian_Fire]

I order Robaxin thru my vet, but it is human dosage. I get the 750 mg, 500 count. My mare gets 10 per day, it seems to be the ‘sweet spot’ for her.

This is an interesting thread, since a lot of what’s being discussed I am also struggling with.

As to differentiating between joints, nerve blocks are the only thing I would think to figure that out. Start low, work your way up until you see (or not) a response.

[IPEsq]

His hock symptoms were pretty subtle. Slightly loading his feet unevenly (more apparent if he was barefoot behind because it would cause some distortion in the foot). Maybe bringing a hind foot more midline when trotting on a straight line (part of the loading differently). He might want to swing his haunches out in the canter departure. Looked a little hitchy on a small circle.

SI symptoms were much more pronounced, ranging from a lot of bucking to crow hopping into canter to balking and refusing to canter at all. His lead changes would also go from perfect to slightly late behind. He was never one to cross canter, but that is a common symptom of SI issues as well as losing the lead change entirely. Downward transitions were braced. Sometimes he would hop into an upward transition especially from walk to trot. Looked almost front limb but it was coming from hesitation behind. Also would palpate sore in a SI to lower lumbar pattern. He had a long very mobile back and all of his stabilizer muscles would get pissed off if we let it go too long from the SI compensation. The last time I injected his SI, I caught it at the stage of just hesitating into the canter and being slightly late behind for the changes, and we kept it from escalating.

You may also want to consider proximal suspensory issues with the symptoms your horse is showing.

Adequan won’t really do anything if it’s an SI issue or a soft tissue issue. I would take that $300 and put it towards more diagnostics. And given what’s happening, you may need to inject (for example if it is the hocks) to address the acute problem and then follow up with Adequan. Robaxin could help with the back soreness and the whole body wind up kind of piece to it, but you’ll need to address the root cause also.

[KnockedOut]

I just injected my mares SI this year for the first time. SI flexions are hard to do correctly, but she definitely flexed positive on the SI, more so than she was flexing on the hocks. I think that SI’s are commonly overlooked when it comes to injections. Its always the typical combo of hocks + coffins/fetlocks as a default. We actually omitted doing the hocks this time and she’s been working great. Got a lot of umph back to her step.

I tend to think injections are worth a try. If you see no improvement, then don’t do it again. Plus, every horse is different. I’ve tried two horses on Adequan and saw zero effect. But I have friends whose horses look like night and day on it. They’re all individuals so you just have to figure out what works on them, even if it’s not what fits into your preferred treatment theories or plan.