This is a special day that takes place once a month, here is the information that someone shared on www.examiner.com explaining the event:
So far, these fund raising virtual parties have raised more than $5,000 for organizations such as The Humane Society, Kitten Rescue of Los Angeles and Orphans of the Storm in Illinois. The next pawpawty is scheduled for May 2-3 to benefit the Margaret Green Animal Rescue.
For each pawparty, a theme is chosen and "party-goers" are encouraged to change their Twitter default pictures to something theme-related (see the slideshow below for some cute examples). Prizes are given away for various contests such as trivia and scavenger hunts – all the while people are encouraged to donate even just $1 to the featured charity.
Who can attend the #pawpawty?
The pawpawties are open to anyone with an interest in raising money and getting the word out to friends about the fund raising efforts. Many of the party-goers are animals, or people who tweet as their pets. There are thousands of Twitter Critters online, ranging from dogs and cats to hamsters, gerbils and even a moose!It is not necessary to be an "animal" to attend these virtual fundraisers, however. Everyone is welcome – the more attendees, the more opportunity to raise as much money as possible for animal charities.
If you decide to join in, be sure to follow us and say hi, I share my owner's account and we trade off regularly - http://twitter.com/happynutrition. And if you click on this #pawpawty link, you'll be taken just to the search results for pawpawty, and see only the "tweets" related to the event. See you there, I hope!