spg - st regis, w, luxury collection - for example >
http://www.starwoodhotels.com/stregi...language=en_US
seems some of the luxury collection haciendas in mexico are pet friendly

hyatt - http://www.mendoza.park.hyatt.com/en...et-policy.html
seems PH buenos aires is also pet friendly (and "winter" down there is jun/jul)

hilton - waldorf