I find my guy barks, as in annoying high pitched barks, not play noises, when another dog that he wants to play with doesn't want to interact, but is a little too scary to bully (via nipping his ass) into interaction. So typically it goes like this:

sniff sniff
Shiba does some play signalling
other dog just looks away
Shiba tries an exploratory whine or other noise, or maybe an arm slap
other dog gives him a warning
Shiba goes into play bow, or down, and barks.. many times over..
other dog keeps ignoring him
at this point the only solution is to find him something else to do.

On the other hand if the other dog is willing to interact and play fight boisterously, there are only nice play noises.

@Rikka....thats what @Tatonka does to Bootz!

Bootz usually try to sit on his face though to stop the nipping. lol.

I will say with my experience in daycare, some dogs find that very annoying. Keep in mind they are with multiple strange dogs, and sometimes it can turn into giant barking everybody nipping one dog session. I've also seen a retriever do it to an older dog once, and the normally docile dog turned around and shreaded his ear. Its just not behavior I ever allowed in daycare unless both dogs were enjoying themselves. Usually you remove the intiator if they don't let up.

I don't think its a bad punishment, and sometimes when it came to the shibas, they would do that because they wanted space (the older they got, the more intolorant they got of daycare, and if they got annoyed they would either get snippy/jerky, or bully dogs). I think the leg nipping is just not something most dogs tolorate, especially if you can have dogs with possible joint issues. Kenshin for example is not allowed to do it to zora because of her bad hips, but he knows its ok with his friend down the block.

Good luck finding another daycare. I had a similar experience.

We were trying to socialize Niktia and I finally found a place with socialization classes for dogs of all ages since she was 2 at the time and had been attacked by another dog before we got her I wanted to try to get her to a class. I found a place that was over an hour away but liked that they used positive reinforcement most trainers in my area still use choke collars. I talked to the trainer for about a half an hour on the phone and she was willing to work with Nikita and thought the best time would be doggie play time when the owners stay with their dogs so I could learn to read her body language better. The trainer was really good with her and teaching me how to read her body language we went for 5 weeks 1 day a week. On week 5 someone brought in a little terrier she had been the smallest there for the previous weeks so I was keeping her away per the trainer till we could do a meet and greet with the trainer to help (she was busy with a lab that was bulling everyone out of the pool). The terriers owner had been told to stay in the pool side but decided not to listen and brought her dog over and set it down. Nikita took off after it by the time I got to her she had the poor little thing pinned with her paw but did not have her mouth on it. My mom has a yorkie terrier mix that she plays with at my moms house and she has done the same to her not sure why she tries to do that but it is only when we first get there and they play ok but we don't let them play long because the yorkie is older and can only handle about 15-20 min at a time. Their were no puncture wounds and they took the the dog to the vet and it was fine. The trainer asked me to skip a week (she would be off) and come back, saying it was not our fault the lady who was in working on her training certificate said Nikita was not aggressive while doing it and seemed to be playing since she had saw what happen and the trainer had not. Nikita had actually played with the labs and play bowed to the grayhounds instead of staying right next to me that day so she was making progress.

When we returned the owner was there and not the trainer. She looked at Nikita and said "why would you bring a shiba to doggie play time no shiba likes to play with other types of dogs? My husband raises (shows,breeds) Basenjis and I would never bring one to play time." She said this while Nikita is playing with her lab friend. We were asked to leave and not come back, with her comment I would not have gone back anyway.
I found a rescue that is willing to let her come over and work on socialization when they have bigger dogs and since the head of the rescue is a behavioralist I feel comfortable, we start sessions in the spring (I am due to have a baby in the next few weeks and I just found her a month ago so we are waiting so I don't have to take the baby too).
She loves to try to get Toby to play by play bowing and barking or nipping at his back legs but he refuses. It has even got to the point if he is carrying his stuffed animal around she will nicely try to grab the stuffed tail and pull but he releases it immediately and it falls to the ground since she leaves it there I am pretty sure she is just trying to play and not take it from him. I know she loved the last few times we went because she would be wagging her tail when we got off the highway. The only people I know that don't have 5lb dogs are our neighbors who breed English Mastiffs and they won't even let there son play with my boys because my kids are to rough with him (there son is 13 mine are 9,8,6,4) when he comes over, so I doubt they would allow Nikita over.

Hope you can find some where that is willing to work with Sagan and follow what you want for him.

@Rikka my two poor dogs would never be allowed out of a crate if "chicken-legging" calls for time outs ... at home my two dogs if they are not trying for the World Wrestling Smack Down via mouth wrestling they are going after each others back legs.

I don't use daycare a lot, but I was very fortunate to find a day care center that while they start segregation by size they don't hold to it if they clearly see a smaller dog better fits with the bigger dogs, which in Bear's case is very true. Bear is typically bored by most small dogs other than the real high energy runners.

@Rikka, he doesn't even notice how much money disappears until i mentioned it to him lol!

@Tatonka...get a house near us ;) then i can take Tatonka. Woot woot!

@Rikka good luck on finding a new daycare for Sagan. There are a couple of doggie daycare places closer to our house, but we were not impress with their establishment or they don't really have a lot of experiences with shibas. Nowadays we drive a little further to take Sam to a daycare that has way more experiences with shibas. I am glad to know that Sam is always happy to be there!