Definitely try the PSSM2 diet. It’s quite different from the PSSM1 diet. PSSM2 is more common in warmbloods and can be triggered by something like being imported.
2 Likes
Because he has tied up, I would assume you are probably dealing with PSSM type 2 or MFM. I would get a muscle biopsy. Keep up the vitamin E and add protein. As much protein as you can. Be careful of too much sugar.
The struggling to maintain the canter is a pretty classic sign of PSSM type 2. As is the tripping.
My PSSM 2 mare is severely exercise intolerant and 20 minutes of light walk/trot exercise will provoke symptoms. Usually she runs out of energy and then starts to trip, struggles to pick up her feet.
Ask him to canter right when you start working him (no warm up). Can he canter normally at this time? Then do walk/trot for 10-15 minutes and ask for the canter again. If the canter deteriorates that’s a pretty suspicious sign of a muscle disease. Don’t do this under saddle. You want to see how he is moving.
Unfortunately the prognosis sounds poor no matter what the issue is. Muscle diseases are not something that the diet alone will cure and it’s something that has to be managed continuously and the horse may continue to have symptoms.
My mare is happy as a pasture pet and is happy to walk around the yard and maybe go for a really short hack down the street and back. That’s it. She will always be limited, which is a shame because she had such amazing potential (and as a younger horse she would jump anything you pointed her at). She was never quite right behind. It wasn’t lameness- it didn’t feel painful but it’s like her muscles just never really worked right. She runs in the pasture and acts like a happy horse, just can’t perform any sort of prolonged exercise. A short sprint and she’s done.
If it turns out to be something else, please let me know. I did not do exhaustive diagnostics because my mare is a pasture pet for the most part and finding out what is wrong isn’t going to change her situation.
Could all this be related to the vitamin E deficiency ? I would think it’s possible. I also think sometimes these horses just don’t utilize vitamin E the way they should.
2 Likes
Thanks for keeping your girl as a loved pasture pet. 
Too many horses get dumped to horrible ends when permanent issues arise.
3 Likes
Isn’t there a known but poorly characterized vitamin E deficiency related neurological thing specifically with Irish horses?
After ruling out a disease that requires treatment such as EPM, I would let him be for a while. I feel like a lot of these 4-5 yr olds go through phases of growth that affect their balance and movement and we often just ask too much of them too soon.
5 Likes
EDM and eNAD are linked to vitamin E deficiency. There are some genetic links…but there is also a recent jump in cases that are not connected to the earlier research published on the young horses with vitamin E deficiency. The newer cases are the explosive behavior plus some neuro signs (Dr. Johnson at New Bolton has been seeing many of those cases).
3 Likes
What is the likelihood of an Irish horse not having adequate access during development to green grass though? Vanishingly low.
3 Likes
Exactly…though some thoughts are not that they lack access to vitamin E, but there is something in the body’s ability to uptake or use the available vitamin E.
My gelding was raised on KY grass as a foal and mostly lived outside in a herd and he had very low vitamin E and eventually diagnosed with EDM. But we know it was not due to grass access as a foal.
5 Likes
We had full neck/back x-rays. Pretty much shot everything and all was clear. Plan to look into EPM.
Dentist was just out. He was floated but no other issues found.
He does not have draft.
1 Like
I already had all of those x-rays and he was clean.
There is a specific sequence for ECVM that is not included in the usual back & neck x-rays. Many vets don’t even know how to take them.
I took full body x-rays of my guy as part of my PPE, but the ECVM didn’t show up until he started exhibiting symptoms and we took the specific sequence. There are instructions for vets in the ECVM group on Facebook.
3 Likes
Thank you for this. Sounds similar to what you are describing. One vet did say a lot of his symptoms can be tied to Vitamin E deficiency. I am hoping that is it (and that isn’t being brought on by something like EDM). Unfortunately I agree… the more and more I read, the more I think his prognosis is not good, which breaks my heart.
3 Likes
Ahhh okay. Thank you.
1 Like
I got about halfway through your list and immediately thought EPM. My gelding finished treatment in late December and we are just about ready to pull blood again. His symptoms were very mild–the vet described it as a performance issue, he just didn’t want to sit on his hind legs and push. That combined with a very mild neuro exam lead us to pull blood and ultimately treat after antibodies came back elevated.
There are so many good treatment options now! EPM is pretty easy to rule in/out.
1 Like
Thank you for that info. So you only did blood? You did not go through with spinal tap?
Yep, just blood. Pathogenes is the lab my vet uses.
ETA: I’m in MI and EPM is extremely prevalent here as well.
1 Like
Most vets don’t recommend spinal taps anymore. Treatment is extremely safe and well tolerated (albeit not cheap). Blood tests aren’t perfect, but the titer levels are much better than they used to be. We use Cornell.
The hard part of EPM, imho, is assessing a horse that has had multiple infections and exposures over a lifetime. On a new import, you won’t have those issues. If he’s positive, it’s a new infection and you treat. In the northeast, it’s hard to find horses that haven’t been exposed - and different vets have different thresholds for when they recommend treating both in terms of test results and in terms of symptoms.
5 Likes
My vet will not do a spinal tap. She feels there are too many risks. UC Davis has processed the blood tests on my horse.
2 Likes
This screams PSSM2 / MIM to me. See my experience with my young mare here - also started right around age 4-5:
I will add that my mare also drinks a lot and pees a lot. I have typically attributed it to PSSM2 but do not know the connection or whether that is in fact the driver. But the fact that your horse had a tie-up, seems prone to ulcers / girthiness, serious muscle tightness that doesn’t seem to be resolved with body work, poor muscle development and top line, toe dragging…all of these were hallmarks for my mare.
Whey protein, magnesium, and Vit E are the most impactful for my mare, along with the turn out and regular exercise – but the protein and magnesium are critical. We ran out of the magnesium for 2 days and it triggered a 2 week flare up of symptoms (tightness, bucking/kicking out, spooking, toe dragging, rock hard muscles, etc)
My vet sent us to Alamo Pintado hospital and they said that the blood test will only show if the horse has ever been exposed, not whether it’s currently causing the symptoms. Alamo recommended the spinal tap.
