A dog or cat party can be a fun and rewarding experience if planned properly. The first thing to consider is getting the pet to human ratio correct. I suggest more humans than pets and only stick to pets that your pet is familiar with as this will make them feel a little more secure. If you are holding the party at your house, keep in mind that dogs and cats are very particular about their territory and can get a bit stroppy when other pets try to spray their scent in these areas. You may have a spraying war on your hands especially if there are too many male pets at the party. I suggest keeping the amount of pet guests to a maximum of 3 or 4 and the human guests to a maximum of 6 to 8. Dogs can get confused and may resort to nipping or jumping when they are confused or frightened and this may be undesirable for your human guests.