We has it.
I arrived to feed Fox on Friday evening. I noticed straight away. He wasn't tracking up, looked like he was almost walking on tippy toe, and didn't like putting any weight on it. Worst of all his fetlock made a strange almost popping movement every time he put it down. Checked all the way up and down his leg. He had a puffy fluid filled just above his fetlock. It was warm to the touch but not painful. He also has some extreme sensitivity on his back around the point of hip. Very bad :(.
I cold hosed his fetlock for 20 minutes and saw an improvement in his movement. I put him away for the night to re-asses things in the morning. Vet's here are unfortunately a bit useless when it comes to horses here. I read Andrea's Eventing-A-Gogo blog with envy at the resources.
The next morning, Fox was moving a lot better he was tracking up a lot better, putting more weight on it and best of all the horrible popping movement was gone. I cold hosed him again which seemed to help again.
This morning I cold hosed again and by the evening the puffiness was pretty much gone his movement was almost back to normal but still resting it quite a bit. Which leaves the soreness of his back/pelvis. I am calling a physio first thing in the morning. Hopefully she will be able to figure out what's going on.
As there is two points of soreness, it's hard to figure out what's actually causing the lameness. The hip, the puffiness above the fetlock which could be tendon or ligament damage or a combination of both. I will keep cold hosing in the meantime and hope the physio can come very soon.