I just returned last Saturday and needed a proof of rabies vaccine, a letter of good health from my Mexican vet dated maximum 5 days prior my departure. I was asked if I usually pay the $35 'dog tax' (the immigration officer call it) and I said I haven't since the pandemic and he told me I was lucky again and not have to pay! (I know I was not going to pay because I saw there was nobody behind the "cashiers'" booth at 11h30 pm).

On a side note, I had checked the box if I was over my limit of booze and cigarettes because I always have a delicious 1.75 liters of Kirkland Vodka with me. He asked again if I usually pay a fine for that and I said no. He checked in his computer and said "sure enough, you are lucky again, I am not charging you".

A suggestion, when boarding the plane tell the flight attendant that you are traveling with a dog and ask for a confirmation that your dog is on board... Air Transat came and offered a little paper specifying my dog was on the flight!

Safe travels!