Why my 3 year old mare who recently came up sore on her right hind can hardly put weight on it?

Thanks for the advise everyone. Had the vet out this week and turns out she has very advanced navicular
Check for an abcess with hoof testers.
Have the bet come check it out. We'd need more info on here to give you further recommendations.
I would have a vet check her for a tendon injury. I am dealing with that now. No fun but apparently getting treatment quickly can really make a difference with recovery.
Check the hoof by putting pressure on different areas on the bottom of the hoof to check for stone bruises. If untreated these can turn into abscesses in the hoof
She's propably just temporarily lame, keep doing the same thing (little to no turnout if possible as well), probably worth calling your vet to give them a heads up. If it doesn't clear up after ~6 days it'd be worth getting the vet in.
I would have a vet come and check it
She also hardly reaches forward with that leg at a trot and won't put any weight on it at a canter. I've tried wrapping for 2 days and ligament daily.
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