Extra horse?

I joined the game earlier in the year, but then I got busy and unfortunately haven’t been able to spend much time on it.  I logged on earlier this week for the first time in a while and noticed that I have an extra horse, a weanling that I never bought or received before.  When I look at the horse’s page it says it is located at Gust O’Wind Farm, so I assume this is the rightful owner?  I wasn’t sure if I should report this as a bug, so I apologize if this is in the wrong place.