Something I witnessed yesterday when I was picking up my son from the after-school club. There was a little dog tied up at the edge of the playground - which is perhaps not wise and I wouldn't leave a dog there alone if I had one, but it's not against any rules.
I saw three boys in my son's year (meaning they were 5 or 6 years old) tormenting the dog. They were running right up to him in an aggressive way, bending down and shouting right in his face and spitting on him. It was horrible to see and the poor dog was obviously highly stressed. There was a staff member outside but she was playing football with some other kids and hadn't noticed what they were doing. I told the boys to stop it and informed the most senior staff member who called them inside and told them 'the dog doesn't like that'.
Obviously not all children have experience of dogs so I can understand that running and shouting around them is sometimes not meant in a bad way and they just need educating. But they were shouting rude things at the dog (not that the dog cares about that, but I think it indicates that they didn't mean to be friendly to him) and I don't think there can be any reasonable explanation for the spitting.
I described what I'd seen in the parents' group chat, not naming the children of course but just saying can everyone make sure their kids know that this isn't acceptable behaviour and can be dangerous because frightened dogs are much more likely to bite.
I feel it was a very disturbing and serious incident. WIBU to send a follow up email to the school, which is separate from the after-school, about this? Maybe suggesting it could be made against the rules to leave dogs unattended on the playground, for everyone's safety? And that someone speak to the children about the importance of being kind to animals (which you would think that they should have learned at home but obviously not).
Or should I just trust that it has been dealt with appropriately?