DSLD "diagnosis" in young, lame horse -- UPDATE post 130, he's gone

[vineyridge]

If I were you and in the Mid Atlantic region, I’d follow Laurierace’s advice. I’d suck it up and send him to New Bolton for their diagnostic process. You’re spending oodles of money on what seem to be independent vets, several of them, and vet schools, especially New Bolton type vet schools, have all the experts right there within a single facility that is set up with all the latest technology and research information to do the best possible diagnostics and treatments available anywhere in the world. They will be able to tell you from vast experience what the prognosis for his future is likely to be within a high probability. After you’d gone through them, you’d know–as much as such knowledge can be gotten with today’s high tech vet procedures. Then you can decide based on what you will know.

If you are not willing to do that, I completely agree with findeight. Give Dr. Green his chance. If he fails, then euthanize.

[Stacie]

As I understand it, the lesions come from tissue not healing correctly. This is why its considered a degenerative disease. Your poor guy has lesions at a very young age. If the lesions are not from disease, what do you think they are from?

[mvp]

@Libby2563

I wondered about this myself. There certainly doesn’t seem to be much funding for DSLD studies, or we’d probably know more by now. The vet who mentioned donation said something about use as a blood donor.

I understand and appreciate your reality check. This would actually be so much easier if he were unhappy or in obvious pain during daily activities! I’m watching him meander around with his buddies enjoying the spring grass right now. His walk is still huge and elastic (last vet we saw noted that there was no sign of discomfort whatsoever at the walk). He naps in the sun as much as he ever has. He has no trouble getting his hooves trimmed. He romps and broncs sometimes and only in the trot can you see lameness. He’s always the first to meet me at the gate with bright eyes and pricked ears, waiting for kisses and attention. I have a good relationship with my local vet, who is very down to earth, but I’ve actually wondered if I can even get a vet to put this horse down when he shows no real signs of suffering. It also makes me feel like I’d be euthanizing him for my own convenience rather than his benefit.

ETA: I hope I don’t come across as stubborn or argumentative. I am processing everyone’s input and finding it valuable. It’s just a really difficult decision to make at this point–which is why I asked for input! And I want to get all of my second-guessing out of the way now, rather than making a decision and regretting it later.

1. Being a blood donor horse is not a bad life at all.

2. No need to apologize for bringing up the “what ifs” or new angles on the situation. You have gotta do what you gotta do in order to think through this situation to your own satisfaction. No one else is in quite your spot so, IMO, no one else should judge your process… at least as long as you are being honest with yourself about the horse’s quality of life.

I do wish you some comfort in whatever you decide.

[brody]

@Libby2563

I wondered about this myself. There certainly doesn’t seem to be much funding for DSLD studies, or we’d probably know more by now. The vet who mentioned donation said something about use as a blood donor.
…

ETA: I hope I don’t come across as stubborn or argumentative. I am processing everyone’s input and finding it valuable. It’s just a really difficult decision to make at this point–which is why I asked for input! And I want to get all of my second-guessing out of the way now, rather than making a decision and regretting it later.

you absolutely don’t come across as anything but caring, concerned and processing a whole lot of info.
I am so sad for you. What a horrid rabbit hole so young

thinking best thoughts the right answer presents itself to you soon so you can start moving on

all of your options are reasonable and fair. They are all also individual what might work for me might not for you <3

best thoughts

[Elouise]

Sent OP a PM.

[kiwichick]

Has a bone scan been considered? It just seems like there is a lot going on here, and a MRI just of the front feet wont give you all the answers (like another poster said, maybe even none)
There are very very many suboptimal conformation horses around, but not all are lame, and for a 5yo to be completely broken down, that doesnt seem like the contributing factors to me personally.

The MRI seems expensive and I bet you wont find out anything you dont already know (and still be wondering about the hind end)

Im convinced if I ever have anything non-straight forward with my horses now, im doing a scintograph. Ive seen it diagnose horses that have weird and wonderful and very difficult to diagnose issues, and I think it would cost less than the MRI.

[Lord_Helpus]

Oh my. I don’t know if you read my thread(s) about Goober, so I will give you the Cliff Notes version: Goober: 6 year old (was five when this started) gorgeous Hanoverian. 17.1 Beautiful mover. Got scores of 78 and 79 at first level. He is all Hano, top and bottom. W line on top and R line on the bottom.

When training for 2nd level (asking for collection) he developed a toe drag left hind. Every possible test and scan were done. After 8 months and no answers, soft tissue was suggested, and we started from scratch. I was told he was not a candidate for surgery and there was nothing more they could do for him. So I got a 2nd opinion from Dr. Kent Allen who suggested we have him tested for DSLD…

When I had been sure it was DSLD, I had stopped all efforts to make him better, since nothing would help him…

My plan had been to participate in the U Georgia research to the extent that he would be euthanized and then necropsied. I would take him to Ga, and would stay for several days for tests, and be there for him until he was gone. I would NOT let him stay alive when he was out of my control.

And I would NEVER allow a horse of mine to be a blood donor horse, Never, never, never.

But it was good news! We sent the nuchal ligament to U. of Georgia — and it came back NEGATIVE! Just to be sure, since DSLD almost always affects bi-laterally or quadrilaterally, I had the RH scanned and it was clear. So I now have a horse who will not die soon.

(Aside: How long did it take for the hole created when the harvesting of the ligament was done? It has been 5 weeks now and poor Goobs still has an open hole with gobs of puss. Vet insists it is normal because he had to go in 3 - 4" to get a big enough sample. G has taken over 700 SMG’s and has had 3 shots of Exceed. (and 4 weeks of Bute…) I say that this is not OK…).

PS: Is New Bolton actively doing research on DSLD? I was told that Georgia was the only place that had active studies going on.)

My heart goes out to you. FWTW, I had not planned to keep G around for years as a pasture pet. Possibly through this summer, to enjoy the grass, but not for much longer than that.

Horses ---- they will break your heart.

I think I haved PM’d most of the posters on this thread. Perhaps we should start a “Misery Loves Company” group.

As it stands now, he is doing “focused shockwave” every 2 weeks. We are doing sonograms every 3 - 4 months. slight improvement since last Nov, and guarded hope he can be a trail horse.

[J-Lu]

@Libby2563

That’s the problem: “as sure as she can be.” Based on her own descriptions of the test, it is not definitive. I’m attaching a pic of the info sheet she gave me via the vet that performed the biopsy. In case it’s hard to read, it says:

“This test is not definitive for DSLD, but will only indicate if the horse has histologic lesions consistent with DSLD. As of now, recommendations on breeding or treatment of affected individuals should not be made based solely on the results of this test. A negative result indicates that in all likelihood the examined horse does not have DSLD.”

I am so sorry. I’ve learned a lot in the last few days.

It seems that the researchers who developed this DSLD test don’t have a gene in hand. They know that ligaments have a higher expression of proteoglycans and that at least decorin has an abnormal structure. These are associations with the horses they studied, just associations, but they really need to definitively know that horses who don’t have DSLD don’t have these changes, and horses the do have the changes. That’s really difficult to prove and they don’t have the n size to say for sure. I’m pretty sure that is why you got a letter and communication with relatively vague wording.

Looks like there’s a 2016 PLOS One paper that simply notices differences in TGF-beta signaling related to cell metabolism. That’s difficult to know whether these changes are causative of the condition, or are a result of the condition without further research because TGF-beta signaling is involved in so much.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5130251/

As someone who designs and executes human and mouse cell experiments, I don’t know why they changed media in the cultured cell experiment. Confounding.

I suspect there is little money in investigating this disease, since it is not “human” and the science required to get to the bottom of this requires a lot of money and a good number of definitely negative and definitely positive samples. The special staining relies on the fact that the proteoglycans are already made, but a genetic profile that leads to the making of these proteoglycans would be of interest. Comparing the genetic profile of truly negative horses with truly positive horses is necessary…and expensive…and difficult to get samples. Biopsy samples can’t be used because they are prepared for immunohistochemistry (probably fixed upon collection), but perhaps in the future samples can be collected for genetic testing and immunohistochemistry.

in short, I don’t think the researcher at U of Ga can really say much more to you that giving you probabilities. She’s a scientist, she knows her test is not conclusive, just suggestive. I can appreciate her logic. Her team is working hard to learn more about the disease and thus hone the diagnosis.

Again, I’m sorry that you have to experience this, but very happy that if your horse HAD to experience this, he had you for an owner. A horse couldn’t ask for much more than this guy is getting from you.

[Lord_Helpus]

J-Lu, you are right on all accounts. In my will I had left the bulk of my estate to retired racehorses. But now I have talked to my atty about leaving most of it to equine research, some of it earmarked specifically for DSLD. (I am almost 69, so the bequest will be distributed sooner rather than later) The fact that it is hereditary should make it relatively easy to identify, as soon as they know what they are looking for.

My theory (it and $2 will get you a cup of coffee) is that XX% of horses who have the gene will not show it because of conformation. But, for horses like ours who start with longish sloping pasterns overstress their legs and the faulty nuchal ligaments give way. After all, the nuchal ligament exists throughout the body, yet it does not fail like it does in the legs.

Another theory is that both the sire and the dam must have recessive genes for the wonky nuchal ligament. It’s the old tongue rolling gene that we learned in basic biology. I can still remember everyone sticking out their tongues to see who was “special”. (NB: I am special)

PS: I have seen several videos of famous performance horses whose fetlocks touch the ground when bearing weight. I marvel that they are still at the top of their discipline.

[Libby2563]

J-Lu, thank you SO much for doing some research and chiming in!! (And for your kind words at the end. :)) Maybe a tough question to answer but if I may ask: if it were your horse, how much stock would you put in the result of the test, knowing what you know?

@Lord Helpus

My plan had been to participate in the U Georgia research to the extent that he would be euthanized and then necropsied. I would take him to Ga, and would stay for several days for tests, and be there for him until he was gone. I would NOT let him stay alive when he was out of my control.

…

(Aside: How long did it take for the hole created when the harvesting of the ligament was done? It has been 5 weeks now and poor Goobs still has an open hole with gobs of puss. Vet insists it is normal because he had to go in 3 - 4" to get a big enough sample. G has taken over 700 SMG’s and has had 3 shots of Exceed. (and 4 weeks of Bute…) I say that this is not OK…).

PS: Is New Bolton actively doing research on DSLD? I was told that Georgia was the only place that had active studies going on.)

I have indeed followed the Goober saga!

Interesting idea to take him to UGA for short-term research. That is something I would be comfortable with, if it comes to that. Was that something Dr. Halper or someone else there said was an option? If New Bolton is doing research on DSLD, that’s news to me. The only other place I’d heard of doing anything was U of Missouri, from Kent Allen, but he said it with sort of a question mark so I really have no idea. I’m not quite at the point of donation yet but I’ll keep looking for options.

Honestly, without putting your vet down too much, that does NOT sound normal! That is awful. I haven’t taken a pic of my guy’s incision since it was puffy the day after but it has only been 2.5 weeks and it is healed. I’m taking the stitches out later this week (vet first said 2 weeks then we decided on 3 to be safe). There was never any pus whatsoever, and he did not need anything beyond the Excede given the day of the biopsy and a couple days of bute. I wouldn’t accept that this is normal, sorry! I would probably see another vet at this point, after 5 weeks (!!!) of pus and antibiotics. Ugh! Sorry you are going through this on top of everything else.

[theresak]

U of WI is running/participating in a DSLD study too…

[Angela_Freda]

@Lord Helpus

J-Lu, you are right on all accounts. In my will I had left the bulk of my estate to retired racehorses. But now I have talked to my atty about leaving most of it to equine research, some of it earmarked specifically for DSLD. (I am almost 69, so the bequest will be distributed sooner rather than later) The fact that it is hereditary should make it relatively easy to identify, as soon as they know what they are looking for.

My theory (it and $2 will get you a cup of coffee) is that XX% of horses who have the gene will not show it because of conformation. But, for horses like ours who start with longish sloping pasterns overstress their legs and the faulty nuchal ligaments give way. After all, the nuchal ligament exists throughout the body, yet it does not fail like it does in the legs.

Another theory is that both the sire and the dam must have recessive genes for the wonky nuchal ligament. It’s the old tongue rolling gene that we learned in basic biology. I can still remember everyone sticking out their tongues to see who was “special”. (NB: I am special)

PS: I have seen several videos of famous performance horses whose fetlocks touch the ground when bearing weight. I marvel that they are still at the top of their discipline.

He’s famous only in very small, exclusive circles, but Yo’s fetlocks articulated very low when he moved.
He never had a problem, Dressage, jumping, riding out on terrain… until he was 23, stressed, ulcer’d and those fetlocks then fell.
I have always wondered about that, horses who have what appears to be pretty extreme flexion in the fetlock and if they are somehow more likely to be DSLD/ESPA.

[Libby2563]

@theresak

U of WI is running/participating in a DSLD study too…

Thanks! They just want DNA samples, not horse donations, but I reached out to see if they want his.

[Libby2563]

I finally got the actual biopsy report! For anyone who is interested, this is what it says:

“Pathological findings and opinion: Tissue (2.5 x 1.5 x 1cm) fixed in formalin received. Histopathology reveals mostly ligament tissue. Bundles and fibers of the ligament are separated by a network of light blue, and in some areas by darker purplish strands of acellular material on H&E stain. This material stains blue with trichrome for collagen, but also with alcian blue for proteoglycans. In addition, alcian blue stain reveals several pools of proteoglycans. The quantity of proteoglycans appears to be excessive, especially for the age of the horse. This is likely due to underlying DSLD.”

[J-Lu]

[quote=“L![](bby2563,post:30,topic:445914”]

J-Lu, thank you SO much for doing some research and chiming in!! (And for your kind words at the end. :)) Maybe a tough question to answer but if I may ask: if it were your horse, how much stock would you put in the result of the test, knowing what you know?

[/quote]

I looked at Dr. Halper’s papers and some other ones here at work. It seems like much of her work is based on her 2006 paper and her 2010 paper. Her 2006 paper looked at ~28 DSLD horses (mostly peruvian pasos) and 8 controls (mixed breed). She looked at samples from suspensory and other tendons and ligaments from all 4 legs, the nuchal, aorta, eyes, etc. When looking at morphology of collagen and elastin fibers, deposition of proteoglycans, ligament septa morphology, etc. from a whole horse, there was a pretty strong indication of which horses were DSLD+ and which were negative. However, very few of these samples can be taken pre-mortem without compromising performance. The nuchal ligament can (although as you state, a biopsy is not for the faint-of-heart). 17 or 19 horses showed the proteoglycan deposits and associated morphological changes in the nuchal ligament (meaning, 2 didn’t), and 1 of 8 controls showed PG deposition and morphological changes consistent with DSLD (1 was a false positive). She states that many control horses have wear and tear in certain/some ligaments for whatever reason (past injury? Strain?). So they can’t say 100% yes or no in a living horse. (A H&E staining, C, alcian blue - normal horse, B,D DSLD horse - see way below)

Her 2010 paper describes the decorin structural changes.

I did find a 2017 paper describing histological changes in induced proximal suspensory desmitis after neurectomy that resulted in resolution of lameness in all horses. Maybe that’s what vet #1 was going for? DSLD is now considered a system-wide issue, so the studies with local induction of desmitis may not apply to DSLD well.

So, I would put stock in her study, but because a negative horse had a false positive result with the nuchal ligament biopsy, I would keep that in the back of my mind and give weight to the other findings. Even though she probably performs this test for many horses, I doubt she receives the cadavers to see if they were indeed following the pattern or were false positives or false negatives. If the horse presented all of the other characteristics of this syndrome, i would likely consider my horse positive. note: some doctors don’t believe in lupus, and here in NC, there were marketed “quack” remedies for Lymes disease decades ago and some old doctors still don’t think it’s a real disease. I put maybe 90% stock in what any medical or veterinary doctor says, then go evaluate the facts myself.

[IMG]https://media.springernature.com/lw785/springer-static/image/art%3A10.1186%2F1746-6148-2-12/MediaObjects/12917_2006_Article_21_Fig3_HTML.jpg)

[J-Lu]

@theresak

U of WI is running/participating in a DSLD study too…

Sabrina Brounts is a co-author in that PLOS one paper I linked to. The last author, Anna Plaas, studies tendon integrity after trauma or inflammation (such as arthritis) at Rush University Medical Center. Huh, nice collaboration.

[Libby2563]

Thanks, J-Lu! You’re the best. I’ve read the publicly available summaries before but they didn’t include the numbers you did (2/19 “false negative” and 1/8 “false positive”). That helps put it in context. Thanks again.

I searched around for a good long list of DSLD symptoms and this was the most comprehensive I found: http://dsld-vet.blogspot.com/p/symptoms.html

Of those symptoms, I would say he definitely has:

Recurring unexplained lameness
Back pain/soreness or soreness/stiffness in hips
Pasterns flexing horizontal during weight bearing
Windpuffs in the fetlock area
Frequent hind leg resting <-- not on this list but I’ve seen it elsewhere; I noticed it last year and asked a couple vets about it, but they said not to worry
Toe dragging <-- also not on this list but seems significant to me

So he doesn’t have anywhere near all the symptoms (though I doubt any one horse has ever actually had ALL of those symptoms!) but he does have a few. He also had suspensory pain on palpation before the neurectomy. No enlargement though. He’s pretty young and hasn’t seen much use, so I wonder if this is a case of catching it early enough that some of the symptoms aren’t there yet?

By the way, I have Lyme disease myself and I pay out of pocket to see some pretty high-end specialists since the mainstream medical establishment doesn’t “believe” in chronic Lyme disease, so I totally see what you’re saying there.

[theresak]

I wonder if you could contact the researchers who are looking at the biopsies and see if they’d be interested in following your horse for months or years - re-doing biopsies and tissue slides to watch the progression of changes.

I suspect most horses only have a single biopsy done and if diagnosed DSLD, are euthanized or retired. If they get some control tissues samples of horses at the same ages, your likely DSLD horse’s samples could help with evaluation of biopsies of horses of different ages going forward. The researchers may be able to take the horse into their school herd or pay for veterinary treatment while your horse is “on study.”

Lastly, even if you think your horse is not in great distress from the DSLD and/or you aren’t convinced of the diagnosis - run a scenario in your head where you are sure he’s got DSLD…What would you do with him if that was his only issue right now? Would you retire him? Would you try to keep him in light work as long as he could? Would you try different treatments and supportive care? Then I’d bring that decision to your vet and ask them to help you determine what to do to chase the front end lameness - further diagnostics, 6 months in the field since he’d be retired anyway, try some injections…My vets are very helpful discussing diagnostic and outcome scenarios and percent likely hood/recovery based on quality of life and cost.

[Lord_Helpus]

Libby ! My bad. I did not even look at your screen name. DUH!

If you are still on the fence about the diagnosis, you might consider the following which I thought of and my vet agreed with):

We are doing sonograms every 3’ish months. The first was at NC State in October, then in Jan, now in April. My vet is seeing pronounced evidence of healing. Of course, it is scar tissue filling in, so he will never fulfil my expectations, but it is a good sign.

Do you have old sonograms? Perhaps a vet might read them to see the extent of changes in his bad legs.

Your vets must have been more positive than mine about the potential benefits from performing surgery, since my 2 experts both flat out said that Goobs was not a candidate. I am so sorry it did not work out.

---- In my research --thank God for the Internet. – I found several references to a low Vitamine B1 (thiamine) level in horses with ligament problems. Have you read anything that mentions it? I am very doubtful that there is a relationship, especially with horses who have access to pasture, but I thought I would ask the assembled group.

[IPEsq]

@Lord Helpus

Libby ! My bad. I did not even look at your screen name. DUH!

If you are still on the fence about the diagnosis, you might consider the following which I thought of and my vet agreed with):

We are doing sonograms every 3’ish months. The first was at NC State in October, then in Jan, now in April. My vet is seeing pronounced evidence of healing. Of course, it is scar tissue filling in, so he will never fulfil my expectations, but it is a good sign.

Do you have old sonograms? Perhaps a vet might read them to see the extent of changes in his bad legs.

Your vets must have been more positive than mine about the potential benefits from performing surgery, since my 2 experts both flat out said that Goobs was not a candidate. I am so sorry it did not work out.

---- In my research --thank God for the Internet. – I found several references to a low Vitamine B1 (thiamine) level in horses with ligament problems. Have you read anything that mentions it? I am very doubtful that there is a relationship, especially with horses who have access to pasture, but I thought I would ask the assembled group.

I think the problem with the OP’s horse is the hind suspensories do not look bad on ultrasound. The main soft tissue question mark at the moment is in the front foot, and the OP is not sure about doing a single MRI much less potentially multiple MRIs.