Worried he will be sentenced to jail time. I have medical issues and he is my caretaker. He does have legal representation. Court date in September though I don't know the exact date.
Jail time is always a possibility, but as Mr. Hall ably states, it is highly unlikely in such a case like this. The key thing is that he has counsel. You should direct, or have him, direct these questions to them. They will have unique knowledge of the CWs case and possible outcomes given the DA's office and Judges in that county. Each county handles these cases a little different. Some won't even require a misdemeanor conviction. Make sure he is in contact with his attorney so your (and his) concerns are addressed.
I can't imagine there'd be any jail time unless he's currently on probation right now. If his only criminal record is a DUI more than 10 years ago, then he wouldn't be on probation for that.
From what you're telling me, I say no jail time. If the threat is there, however, the fact that he is your caretaker would very likely persuade a judge to grant probation instead of jail time anyway. Best of luck to him.