I thought it was a very funny episode, specially the pony. It was a good example of BB showing a slightly warped sense of humour. They usually do make a fuss and throw a party for birthdays, not sure why didn't for Tiffany, maybe it was just a launch night thing. They could have given her a cake or something. Though she may have told them beforehand she didn't want a fuss.
Didn't they take in someone's dog once for their birthday?