Is my mare in heat?

Question
I have a 4 year old mini mare. I have a few questions to ask you. One is that since she is 4 years old, I think she still has her baby teeth? Is this normal is it just that she is still maturing, like people take longer? The other is that I want to breed my mare soon but I cannot tell when she is in heat. I do not own a stallion, I would use my friend's stud. Is there a way you can tell when your mare is in heat? The last question is that I have seen people with minis that are very fit. I only give my mare a handful of grain morning and night and a flake with it. I try to do as much with her as I can but since I am in middle school, I get a lot of homework so i try to do my best keeping my grades up. Is there something I can do that can help to keep her more fit? I used to even take her for a walk down the road and back which is about a mile or 2. Or I would lunge her for about 10-15 minutes. I want to keep her fit so I can start showing her. Please answer my few questions.

Thanks, Samantha

Answer
Hi Samantha-
Thanks for your questions which I will try to answer. First, I doubt your horse still has her baby teeth but only your vet can tell for sure. If they are not bothering her and she eats normally, I wouldn't worry about it. Second, mares are generally in heat during the spring to early fall months. Generally, you can tell by the way she acts- squealing, etc. but also they often "wink" with their vulvas as well as urinate cloudy streams. How they react to a male is a good sign if they are kept in separate pens. Third- besides cutting back on your mini's feed, exercise can include lunging or training her to jump small jumps. Both are good exercise- just keep her moving as much as possible. I hope this helps. Best, Toni