I feel like an arse posting this, and am probably being judgy. However here’s the story.
I constantly see a friend of mine posting on Facebook her feeding both her dog and her grandchild completely inappropriate food,
Example - dog - full English breakfast including buttered bread
Granddaughter (less than 1) mc Donald’s breakfast - a whole one - muffin plus hash browns Etc.
I’d never make a negative comment publicly on a post but have seen others quite kindly make hints about the dog (like your vet will tell you off etc).
Would you (privately) say something?