Neurological horse

[GPjumper]

Hi all.
I’ve got a friend in northern Virginia with a puzzling horse. She’s currently working with a Vet hospital and awaiting some more results but I figure I would throw this out to the hive mind here for her. The horse is a 7 year old warmblood gelding.
Horse is neurological. With progression between the initial work up and the bone scan appointment (about 2 weeks apart) Vets see axial skeletal problems and back pain. I’ll provide a list of what has been ruled out.
Negative for wobblers. (Clean x ray and bone scan)
Negative for EPM (positive for exposure but not causing inflammation. Confirmed via spinal tap)
Negative for Lyme. (Blood work)

Muscle biopsy is pending for PSSM.

Is there anything else it could be she should look in to?

[knic]

I would assume they have done basic bloodwork, but liver failure can cause ataxia.

[joiedevie99]

I had a horse with a tumor pressing on the spinal cord. Presented super clear as EPM, started meds, then test came back negative a week later. High dose of steroids for a few days brought her back to 90% (she was already retired due to other issues). She had a few flares, all successfully treated with steroids, before she passed.

[frugalannie]

What is the duration of symptoms: a couple of days, weeks or months? Sudden onset or gradual? Progressing or status quo?

I don’t have any answers, but more details are always interesting.

[GPjumper]

This has been going on a while I believe. Blood work came back normal.
In the last two weeks it progressed. Back in the spring she treated for one month with marquis and saw improvement but a few months later (3-4) he crashed again. EPM came back positive for exposure but not an active case.
That’s all I know.

[findthedistance]

In no particular order:
I thought a myelogram was required to definitively diagnose (or rule out) wobblers? Has that been part of the diagnostics?
Any chance this is a C6/C7 horse? Were they able to get good x-rays of C6?
If the vets that see axial skeletal problems have done x-rays of the neck and back – were the films clean?
A poster on here had a horse with EDM. Hopefully the vet hospital is literate on that unfortunate possibility.

[GPjumper]

All of your questions are answered in the original post. Clean X rays and Bone scan. It doesn’t sound like they are they thinking wobblers at all after the diagnostics. I think they are leaning towards PSSM or Motor Neuron disease.

[2tempe]

A rare possibility: I imported a 9 yr old horse from Spain about 18 months ago; when he arrived in Germany it was noted that the right eye looked NQR and had limited "menace’ response. upon arrival in US, he was sent immediately to Univ of Fla due to the eye issue. He also had other neuro symptoms described as very much like EPM, which is not seen in Spain. Multiple tests, including MRI of cranial nerves led to the suspicion of something called Polyneuritis Equi. It is believed to be auto immune related, and the suspicion was that the stress of being gelded, healing (which was slower than expected) and being in a new setting post castration were triggering events. Over 3+ weeks in US his condition slowly deteriorated, helped only briefly by a course of steroids. Sadly I had him euthanized and the necropsy supported the above diagnosis. In his case there was cranial nerve damage, not trauma related, and it presented with both issues in his head/face and also in hind end ataxia.

[JB]

@2tempe

Polyneuritis Equi

Wow, that is just…morbidly fascinating. I’m so sorry you had that experience

[JB]

Ohhhh, how interesting, in looking up more on polyneuritis equi, I found it’s the new re-name of Cauda Equina which I literally just learned about 3 days ago. Wow.

[GPjumper]

Very interesting. This guy was imported from Germany as a three year old. I wonder if he may have it and it’s slower progressing?

[Peggy]

Here’s some info on NAD/EDM.

pubs-HR29-2-bkm-sec.pdf

[Peggy]

IIRC you have to take specific radiographs to see the C6-7 malformation; presumably this has been done.

All You Need to Know About the Hidden C6-C7 Malformation That's Bringing...

[GPjumper]

Yes. Those neck x rays were taken first. He presents with very tight/painful muscles so the step after the x rays was a full body bone scan. The bone scan had nothing notable on it so the next day, they laid him down and did both the spinal tap and muscle biopsy. Spinal tap came back today. Muscle biopsy due any day.
Spinal tap results were 1:250 for S Neurona. Rood and Riddle ran the spinal tap.
U Michigan is running the muscle biopsy.

[Critter]

EDM is another possibility…my gelding was euthanized for that back in Feb. He was turning 5. If you do a search there should be some posts from me and from some others who have also been through it. Many of the research articles say it’s young horses…but those are not accurate, as they’ve been seeing an increase in horses in the 4-10 yo age range. The tricky part is there is no way to confirm it while they are alive…you can only do the pathology after. One of the clues with my horse was the out of character behavioral changes (got explosive out of nowhere…and it was under saddle and out in the paddock). That seems to be consistent…the neuro signs were subtle for some time…and then progressed quickly. There is a very detailed article in the Chronicle from several years ago from one of the other posters on here that goes through her horse’s diagnosis.
Edited to add there is a relatively new Facebook group for EDM that might help.

[GPjumper]

This sounds like him. Apparently he started with back pain and explosive behavior. She did say he responds well to certain calming supplements (synchill) when others don’t really touch him. She also said he does not shiver. When he got wet in the rain last spring, her other horses shivered until dry. His entire body seemed to seize instead of shake. When they tried shockwave for him, he was fabulous for a few days before his whole body seemed to crash. PSSM type 1 genetics test was done and that was negative. They limped him through those episodes and they notice he seemed odd in the stifle so they treated with Marquis for one month. She wanted to do more but the vet felt it was not necessary. Horse was going very well. Relaxed and back in work. She said he then started exhibiting the weird tightness behind. The stifles came back as if they were due to be injected. Vet came back and sent them to the clinic and this is where she is. In the time between the first eval and the bone scan, the horse did get worse. She still thinks EPM but is waiting for the results or what the next step is. (Sorry just got off the phone with her)
To top it off he is sore in his neck today. (5 days after spinal tap) when he was fine yesterday. It’s like he doesn’t want to drop his head all the way to the ground. She calls the clinic tomorrow for an update and to see if she needs to bring him in. (Plus her regular vet is coming for fall shots)

[2tempe]

My horse vetted fine prior to purchased in early May 2020. First symptoms estimated to have presented in mid May around time of castration. We euthanized late July. Unlike EDM, there was no explosive behavior. He was quiet and loved the vet students grooming him… ‘‘this all truly sucks when it is diagnosis by elimination. The only advantage I had was the lack of a bond; I never saw him mostly due to covid restrictions but also because I knew even one visit would send my emotional side into overdrive.

[Ghazzu]

i could just be tired, but I haven’t really seen a description of exactly what neurologic signs the animal is displaying.

[GPjumper]

Top line loss, instability walking downhills, back pain, paddling up front are the only ones I know of. There may be more but I haven’t asked.

[Ghazzu]

Sounds like a spinal cord issue.
Radiographs were mentioned–was a myelogram done?