Help - sudden change inmares behaviour

[Janiceforsyth]

I have a 4yo mare, and all of a sudden she has changed when being ridden, but only when attempting schooling.
It started last week. Only things I can think have changed are that I tried a jump saddle from saddle fitter for a weekend, last weekend but decided it wasn't quite right. I have changed her feed but gradually and not massively - happy hoof to alfafa A original. I rode this afternoon and when schooling in the field she was tense and just ran off the in the trot - have very little control. Head up in the air and pulling on reins and running.
We did some XC training on Friday and she was fine - jumped well, and seemed happy. I don't understand what's happening. Any ideas appreciated? Will probably get vet out to check her back, and might give her a week off, just to see if that helps. Saddle rode in today was checked in July. Recently had teeth done.

 

[ycbm]

Take her off the alfalfa and see what happens. Some horses are maniacs on it, I have one.

 

[Equi]

Quit the alfalfa.

 

[L&M]

Sone horses can react to alfalfa, and I think that alfalfa a is the highest calorie of the range (but you might want to check that!)......

 

[Pearlsasinger]

I would ditch the Alfa A to start with, lots of horses react badly to alfalfa and it could be that she is just getting too much now. Unfotunately you probably won't be able to go back to Happy Hoof, either now. You will need to find something with no alfalfa.