get your goat

[dancecaller]

It's annoying me (getting my goat, even), that I don't know where this came from.

[valerieb1254]

http://www.phrases.org.uk/meanings/get-your-go at.html

[cobbler37]

This saying is possibly from an old Americanism - is said to relate to a practice among racehorse trainers of soothing a nervous horse by putting a goat in its stall. Someone wanting the horse to lose could sneak in and remove the goat. The horse would again succumb to an attack of nerves and would not run well. The explanation seems contrived however.