First off, I think that there's no set age that a horse "should" be retired at. Personally, I have a 26, almost 27, year old Arabian mare that I ride relatively hard (because she wants to) without a thought. She's always raring to go and I have trouble keeping rides light and easy even when I want to go easy! haha
For instance, yesterday we were trotting and cantering on gravel for about 2 hours and when we got home, she was wanting to canter some more!
I know that for me, I'm going to start thinking about retiring her when rides start not being fun for her. When she stops wanting to run, when she stops enjoying herself on the trail (no pricked ears, no walking faster to explore a new place, etc). Alternatively, if her body starts showing signs of not being able to handle our pace (I try to keep her as fit as possible to combat that) I'll start thinking about retiring her since, currently, she hates going for slow rides.
Some things I can think of with your mare:
What's her diet like? My mare gets less happy about working when something is missing in her diet/she's not getting enough food. I have mine on 15 pounds of alfalfa, free choice grass hay, a pound of a ration balancer, and a pound of beet pulp, daily, and that keeps her happy to work. My mare is a very easy keeper though so if your mare is harder, you will probably need to give her more.
Is she on any joint supplements? Her joints might be sore if she's not.
Do you have the ability to trail ride her on a gentle trail or two? I know my mare gets pissy when we go on the same route every time. She loves exploring neighborhoods, finding kids playing, exploring a new trail, going to the park, etc. I try to mix it up all the time for her so that her mind stays active as well. My thought is that the older the horse is, the more their mind needs to work. They often don't have as much physical energy that needs to be released but I've found that most older horses have a ton of untapped mental potential.
Also, have you checked her saddle fit or had someone knowledgeable do that recently? Like humans, horses change shape as they age and saddle fit can definitely contribute to her enjoyment of being ridden, or not. When my mare starts getting stuffy undersaddle, one of the first things I check is her saddle fit. In her case, sometimes she's lost weight and needs a thicker pad and sometimes she's gained weight and needs a much thinner pad.
Another thought I have is that you say you've always gone easy on her. Have you ever tried increasing her fitness and challenging her a bit more? When I'm out of shape, I hate exercising but when I'm in shape, exercising can be super fun. My mare was crazy fat and completely out of shape when I got her (when she was 23). Once I got her into shape, she became unstoppable. She's really fit and she looks forward to being ridden where she hated it as a fatty.
These are just some things to consider. I think you're doing a really good thing by considering your mare's state and her enjoyment of being ridden. Kudos. :)
Fabio - 13 year old Arabian/Lipizzaner gelding
Hazel - 14 year old Angora goat
Atticus - 4 year old LaMancha/Alpine cross goat
Rest peacefully, Lacey.
Last edited by Wallaby; 11-02-2011 at 01:50 PM.