Beginning in 1933, Germany began passing antisemitic laws. One such law was that Jews weren't allowed to have pets and their pets must be killed. So no Jews would have had pets by the time they were deported. On the other hand, Jewish peasants would have had farm animals. They would have been seized and given to others.

Also, I don't think Hitler was an animal rights activist. He just had fondness for certain animals, but no interest in giving them rights.