Bodhi is seven and a half.
I've had him since he was one and a half.
He's been going to doggy day care for about four hours twice a week for the last four years with out problems.

Recently, they told me that he should stay home for awhile.
He had bitten another dog in the face and nipped at a human who had tried to correct his behavior.
They said he doesn't understand cues from other dogs who don't want to play and that someday this might cause a big fight.
Also, he gets into trouble when other dogs coma and go; there is a big scrum at the fence and he gets too excited.

Before you ask, his behavior at home is unchanged.
He is still enthusiastic and friendly with us, neighbors and their dogs.
His health is fine and we haven't changed his diet.

Ideas?

We really need this day care to work out when I can't be with him during the day or when we board him.

Michael, I think if it were me, I'd get real insistent on "What really happened?"  

I can't picture a good natured dog - one who's been around the day care for more than a while - abruptly deciding to take a chunk out of a dog.  Questions *I'd* be asking would be along the lines of "Was it a new dog?" If Bodhi was getting insistent that he wanted to play, with an unfamiliar pup, I can picture him getting nipped by the new dog but not the reverse.
Who was the "handler" involved, someone new?  What did they do when they tried to "correct" his behaviour?  It's way too easy for someone to surprise a dog and - surprise - they get nipped or bit.  An experienced handler shouldn't have been in the position to get nipped by an "out of control" dog.  (Not saying he was, just their perception of his actions)

Not understanding cues - my Avalanche is a persistent cuss when it comes to wanting to play.  Seriously he'll instigate till the other dog responds with "I *said* no!" (and you know how they do that, right?)  Then he'll go off and find someone else - human or canine - to bug.  I'm afraid that my response to "someday this might cause a big fight" would have to be a sarcastic "Having two dogs in the same space might cause a big fight - so you're going out of business?"  but not until I was disgusted with a bunch of non-answers.

Relative to the scrum - I've boarded my various pups both here and in Houston.  Here the vet tech (I board with my vet) goes in back and gets my dogs - one at a time.  Simply to avoid the chaos of having all three come out into the waiting room at once.  When I boarded in Houston, the only time I ever saw the dogs at play - that wasn't through a window - was when I went to get them.  They had a "porch" separating the main play indoor area from the entrance area - it eliminated the possibility of having all the dogs run out at once.  I went in, on the porch, called my dog to me, leashed her and left.  If they've got a scrum at the door, they're doing something wrong.  Oh, in Houston when two or more of us showed up at once only one was allowed to get their dog at a time.  

Personally, it sounds like they need a little more organization there - not your problem.

I agree with al. I would want to understand the environment better. Chances are it is what has changed, not bodhi. That said, it might be good if you have a friend with dogs who could dog sit for a day and see if bodhi isn't having some kind of separation anxiety that is showing itself when you're away.

He does have some separation anxiety when I leave the house- pacing, searching for me.
I've taken to sneaking out the back door.

But that's not the case at day care.
He is super eager to get inside and won't even say good-bye to me then.

I agree with Al. I've only used day care twice. Two different ones. Both had strict procedures for leaving and entering, including id check, staff member getting the dog, an "airlock" analogous thing and only 1 dog at a time.:-)

They have that- inner sanctum, external iso cages, then customer area.
The dogs get all agitated when one goes from the inner sanctum to the iso cages.

On the way in, the dogs go crazy when a new dog is put in the iso cages.
Then after they quiet down and are used to the new dog, the new dog is released into the inner sanctum.

They asked me to think about bringing him from 10-3, after the work day starts when most dogs come, and before they go home. I'll try it, but it doesn't solve my problem when I need a whole day.

Not sure if this helps but the daycare I was taking Gabby to in MI was having issues with 2 of the other regular dogs (both smaller dogs than Gabby and I know she tends to pick on smaller dogs when she gets the chance). It was pretty consistent from what they had told me so what they did was separated Gabby from those 2 and let her play in smaller groups which had similar hyper dogs. Not sure on their setup there but maybe that is something you could ask they do to help you out.