Q: In reading the article by Dr. McDonnell about the effects of anabolic steroids on geldings and their behavior, I wondered how long the effects last after the steroids are given to the horse. I have a 3-year-old off-the-track Thoroughbred at home recovering from illness, and he is not the same sweet gelding I sent out for training. Even something as simple as leading causes him to go straight up in the air for no apparent reason, and he is finally learning that he cannot bite like a barracuda.

He was very docile before, and now he is aggressive over the fence with the mares and the other gelding.

I would just like to know how much of it is caused by the steroids and how much is newfound self-confidence, as it will make a difference in whether I wait it out or deal with it now