Finishing a colt

Question
I have trained jumpers and am new to the racing world. I am conditioning a 2yr old filly and have taugh her lead changes and am almost ready for her first work. I am having a real problem keeping her straight when she gets moving fast. She is fine at the gallop until I ask her for some speed. Please help!

Answer
hi ---well if she is not changing leads at the right time then i would look for a problem in her shins?? 2 yo's always have shin problems-- always!!  i always paint their shins with a good iodine paint to keep then sound. also the teeth might be bothering her  check for loose caps as 2 yo"s have caps. i hope this helps you  thanks ED HESS