All of my pets are members of my family, even our pig. We've adopted every single one of them that were abandoned or abused, or both. They provide therapy for my Autistic son as well as companionship for the rest of us.
We have 3 dogs, 2 cats, 3 birds, and a pot-belly pig. Our lives, especially my sons, would not be the same without them. I do not believe our pets are a luxury item. They are part of our family.
In ancient times, people used to live in spaces in the sides of rocks. They would keep their animals inside the rock caves from weather elements. Animals have been an important part of families since the beginning of time. Horses, donkeys, and camels, for example, were necessary before cars.
I think it's a tragedy that Mexico would consider such a tax. It just means more animals left to perish with no one to take care of them due to the cost.