You value your in-laws’ efforts to better the world they live in, and it would be wonderful if they did the same–if they saw past their own judgment to appreciate your dogs and all they offer. (Sigh. In-laws.) That said, they do get to champion their cause, and you can recognize it’s merit, even if you’ve made a different decision. You could confront them about the perceived aggression or remind them of the service work your dogs perform. But neither option is likely to bring satisfaction, and you’d probably do better to breathe deeply and let this difference go. Mute your in-laws on social media, love them in the tangled way of humans, and love your dogs in the uncomplicated way of animals.