"...landlord won’t allow it..."
Why? What did the landlord do wrong?
The landlord doesn't allow dogs in his rental properties. This is a perfectly reasonable request. Dogs destroy things.
The tenants violated this rule by bringing in their dog. The landlord told them to get rid of the animal and they complied.
If they really wanted to keep their dog, they could've chosen to rent somewhere else where dogs are permitted. The landlord is under no obligation to alter his rental policies.
Too many people in this world think the rules don't apply to them.
And you think the landlord is the one that should be shamed?