1 yr old boxer peeing in crate at night

Question
Hello, I have a 1 yr old boxer who was easily trained and very consistent up to this last week. He is bell trained, so during the day he will ring the bell on the door and we let him out. Before we would put him in the crate at night and he would not make any messes. All the sudden every morning he's been peeing in his crate, and we're not sure why. We started by taking his dog bed and replacing it with a small towel but he has continued. I know he can hold it all night because he's done it for months, and he can hold it during the day for 9 hours and not make a mess. Last night I also tried to gate him in the dining room (where he stays during the day alone with no messes) hopeing that if he had to go he would ring his bell which would wake us up, but he didnt. He found a rug and peed on it.

Here is my plan for tonight. I'm going to take out ALL of this towels/blankets in his crate. If he decides to pee again he'll have deal with it, instead of having a towel or bed absorb the mess.I'm going to move the crate in my bedroom, so if I here him peeing and I startle him.

What do you think? is this the next step I should be taking? It's just very frustrating that he's been great all this time and all the sudden he's doing this. Thank you for your time and help on this!

Answer
The first thing I would do is to have a vet take a urine sample, just to make sure that he doesn't have a UTI.  Next, try feeding him in his crate (most dogs dislike soiling where they eat).  Taking the blanket out is a good idea, as is making sure that the crate is the right size - only large enough so that he can stand, turn, and lie down, but not "get away" from any messes.  But, the first thing is to give him the benefit of the doubt and insure that there is no health reason for this.  Also,  have there been any changes to your household?  Moving, new baby, noises, construction, anything?  Some dogs regress in their housetraining when that happens.  The solution is just to go back to housetraining 101 for a bit.
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