I have only used the doggy day care once and was shocked when they brought my minpin out to greet me. The attendant was leaning back as my puppy was straining to get to me. Instead of putting on the harness he came in, they had the lead doubled over and around his collar. As he strained to come towards me the quality of his bark changed to becoming hoarse, rather than release tension on the lead she kept the pressure up until I took over and took the lead off the collar.
When I asked her why she didn’t stop, she replied that the pressure on the dogs neck causes a reduction of oxygen that helps them regulate and stop pulling(!!!!!!) Minpins are a small breed, with a tiny neck circumference and it is not wise to continue pressure if you hear hoarseness.
When I tried to talk to them regarding this issue and if they had had any education around this, they stated there was no way this could cause an injury.
Whilst most of this should come under common sense, I thought I would refer to one of the many articles that talk about this risk
https://www.google.com.au/amp/s/healthypets.mercola.com/sites/healthypets/archive/2017/02/12/amp/laryngeal-paralysis.aspx