Well especially for young males this could be a breeding fast. Have you been tracking his weights? This will be the One thing that will save you a hell of alot of worry. If you haven't gotten a digital scale and a notebook by now..... Do so! A breeding fast the animal will lose little to no weight. An illness and they will drop weight quickly. Having an action notebook or sheet to track your bp is the single most important thing to keeping them. It will show you there's a problem way ahead of it being life threatening, you will notice the patterns and if he or she needs to go to the vet it gives you a true back ground on the animal that your memory alone cannot give.
I track sheds, feeds, defecations everytime and weigh in monthly. If the animal stops eating I weigh bimonthly. If the animals losing weight it's time for a vet visit.
Personally it sounds like you have a little boy that is ready to go find a girl this year. But at the same time without watching weights you won't be sure.
The only thing that bothers me is his active roaming during the day.
What's the hide situation like?
What I would do is track his actions starting now, weigh in bi weekly, that will give you a decent baseline. From there just keep offering on his normal feed day and keep things as normal as possible.
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