It's unclear how the Yorkshire terriers will be kept when they are not being made to perform "feats", but the Lonely Planet's description suggests it wouldn't be unusual to see them locked up like its many other animals.
The zoo's oddest exhibit, the review notes: a "huge cage of domestic cats."
ACTION GUIDE: Zoos and Aquariums
Hundreds of millions of people visit zoos every year, despite increasing public anxiety about animals in captivity. If you want to make sure you're at least visiting a zoo that makes efforts to be humane, make sure it is on the list of U.S. facilities accredited by the Association of Zoos and Aquariums; internationally accredited facilities are listed here by the World Association of Zoos and Aquariums. If you want to see whether a facility has any recent USDA violations, you can search this database. You can report a zoo or aquarium to the USDA here. And if you want to become active against having animals in captivity, Peta and Born Free USA offer places to start.