sudden personality change please help :(

[literally anything else]

ok, so i apologise in advance for the essay....i have an 8 year old thoroughbred gelding. ive had him 2 and a half years, so like to think i know him well. he has always had a relaxed outlook on life, had a couple of issues arise i.e started to nip but always sorted it and been fine. only real issues he has is he wont let people ride him when im not present, he will throw them, and he hurt his back 2 months after i first got him and still when saddled will hump his back and walk with short strides for a few minutes (this comes and goes depending on the day) vets and physio agree he is just remembering the back pain and acting up until he realises it doesnt hurt anymore. well 5 weeks ago i had to move to a new field (two of his good field mates came with him) he has been fine up until two weeks ago, when he started to snatch his feet away, be abit stubborn to lead for a split second instead of instantly willing as usual. 5 days ago i went to bridle him and he bombed off with the rein around his neck and put his foot through his bridle and snapped it. 3 days ago i saddled him and he reared up and leapt forwards straight on top of me, i told him off and led him round he was back to his usual calm self, very chilled and loving, next minute he raced at me biting and knocked me over. every day since he has decided he is a stallion ( never had any interest in mares whatsoever) being agressive, any pressure from me to do anything and he flips out, rears when picking feet up, fidgets and stamps and pulls away when grooming, if i pull gently on his headcollar to lead he just flips his lid..when loose in the field he has always been one to 'play' follow me around and enjoys loose schooling..now he will be going beautifully doing everything from hand signals and next second he will bomb at me and be bucking and rearing which will last a minute or so to 5 mins...then he is normal again...will be phoning vet in the morn but any advice? has anyone experienced anything like this? im not a nervous person and have dealt with many problem horses but he is baffling me and i will admit im worried about being injured, so far i only have a bruise from a bite and a pulled muscle in my neck and shoulder but dont want to get seriously injured. thank you for reading !!

 

[kinnygirl1]

Ulcers? Only suggesting as I wonder if his reluctance to be tacked up could be cos it hurts his belly....mine threw himself against the door and wall when I tried to tack him up, he was previously very chilled out about everything! He also walked very tensely when first brought out tacked up but would then settle a bit. He had grade 2 and 3 pyloric ulcers.

 

[Leo Walker]

He screaming at you that its pain! After 2 yrs of no pain surely he'd have stopped being cold backed? Sometimes they are given the all clear but it still hurts! I've had an MRI scan that shows nothing that would cause pain, yet 2 days ago I collapsed in the kitchen screaming with pain so bad I was praying to black out. If I was a horse I'd have been given the all clear, and on a good day Id be ok, but on a bad day its soo horrific I literally cant bear to be alive

 

[literally anything else]

ive only gone on what vet and 2 different physios have said, he hasnt looked distressed ever after being tacked up he normally looks chilled out as hell even though he is walking silly..he will be having a full mot from vets again..just hoping it isnt something too bad

 

[literally anything else]

i did think ulcers, but would that have contributed to the sudden 'im a stallion' behaviour? he mounts my mare, i cant seperate them as he will do anything to get to her (she isnt phased by him). he constantly has his bits out, mounts her and herds her about :/ he isnt actually agressive to her or the shetland he is with just me and doesnt matter if ive tacked him up or stroking him so im stumped !