Poss SI pain (or owner going loopy!)

[diablo]

Evening all
It's been ages since I've been on here but just looking for a little bit of advice....
I have a lovely 9 year old warmblood that I have brought back from Navicular Impar ligament injury to eventing this year.
He has been totally signed off from the vets - they cant believe he is as sounds as he is
So ran first event, total super star jumped like a stag and loved it, slightly faster than OT - very pleased rider and horse
Second event - had a fence SJ, very unusual for him and then got stuck in a pace round the XC, jumped everything just lacking sparkle.
Third event (Sunday, Somerford) another fence in the SJ, and similar in the XC although conditions were sticky when we went round at the very end of the day.
Before all this though tacked him up as usual in the lorry got 2 steps off the ramp and leapt the rest like a lamb and then proceeded to act as though he had never had a saddle on his back in his life, proper bronching rodeo performance with me and dad looking like total numpties stood watching him.
Was fine when I got on.
Watching XC video back landing with back back feet together in a jolty manner.
Plus when I got home very unhappy at rug being put on, ears back, rounding his back, nipping - not like him
I have very little vets cover left with him so looking for opinions before I bankrupt myself!
He is sound - definitely.
Only other thing to have changed is his field about a month ago (before 2nd event) and seems to eat himself stupid all day and looks and sounds like a fat bloke whos been on the beer for the full day session!
Only went out for half days before Somerford for a week so cant think this has a great deal to do with it.
When he did previous injury he stopped wanting to jump but was sound, until he chased sheep around on hard ground and came in crippled
Thinking poss SI pain? Anything else anyone can think of??

Thoughts please.......

 

[SullivanB]

has he had his saddle fitted recently, especially if hes put on weight?

 

[diablo]

Yup sorry should have mentioned saddle checked very recently too

 

[PorkChop]

Problem is it is possible that her is bilaterally lame behind.

I personally would nerve block one hock, purely because it is the most common joint for wear and tear - I would think this would be the cheapest place to start.

Other than that, depending on the finances, a cover all injection such as Osphos might be worth a try - I'd be more inclined to do this with an older horse though.

You know him, if your gut is telling you SI then talk to your Vet.

 

[diablo]

Should also mention here that he has had stifle arthroscopy 3 years ago, was told to keep them moving, but had a long period of box rest with impar ligament injury.
Just doesnt add up with his behaviour?

 

[PorkChop]

Ahh, fair enough, then the stifles are definitely what I would start with then, stifles are a pain in the behind.

A couple of nerve blocks and a scan/x-ray won't be too pricey and its the only way you are going to know.

 

[mega spoilt ponies]

I would be inclined to think gastric ulcers/hind guy discomfort. Fits symptoms (especially hind gut). (Touchy, sour, stuffy, cold backed, change of field, lush grass, perhaps not eating much while travelling? Etc)