Not all dogs are a good fit for daycare, and some don't even like it. There, I said it. Like humans, dogs are individuals with different personalities, experiences, and preferences. Some want to play all day with any and all other dogs. Some are more selective, and prefer certain play styles or speeds. Some prefer not to be in a crowd at all. Others love a good party for a while but then need some relaxation time. And, again like people, some could use a little work on their social skills. As long as the dog is interested and not a danger, we can help these dogs a lot in a well-managed daycare.
One huge factor that can't be changed is what the dog's infancy was like. Puppies who have at least 8-12 weeks with their dam and litter-mates (and possibly other well-matched dogs) have a huge advantage over the millions that are unfortunately weaned at 4-6 weeks. Milk is not all they get out of they life with Mom and siblings. Bite inhibition, learning to read body language, etc. are all well on their way by 8 weeks of age, so letting other dogs teach them how to “play nice” is invaluable. The learning continues, but by 4-5 months there is much less chance of affecting bite inhibition, and other dogs are less tolerant of poor manners in adults than in puppies. Body language nuances they seem to keep picking up for life, so that's where we can have more of an effect. (Bite inhibition refers to the force behind an automatic, reflexive bite from a dog under stress, so it's not something they're concentrating on in that moment. But that doesn't mean you can't teach them to take treats gently!)
So if you try daycare and are told that your dog isn't one of those happy-all-the-time socialites, don't worry! That's OK, and perfectly normal! They might do well in certain playgroups, or with a nap after they play for a while. Sure, we think of them as a social species, but so are we. And who among us wants to hang out with every other human all the time?
I have to go hug Gracie now (and she's doing so well learning social skills!!); more next month!