Originally Posted by Indyhorse
Some horses will not cycle over winter, but the days should be long enough now (assuming you are in the northern hemisphere) for her to be back in swing. Since she is only three, did you notice her cycling last year? They can be pretty irregular for the first several heat cycles. She might be late to mature. Best bet is to get a vet out to check her asap. Horses can and certainly will breed through fences.
Tell me about it...the school's 2 year old colt (who was supposed to be gelded by now!!!!) tried to breed my mare through the fence about 4 weeks ago...then someone let him out in to the main pasture when I was gone 2 weeks after that, and he destroyed part of her corral trying to get in with her...I am on the 'I'm hoping she's not bred' boat too...