It's my party and I'll cry if I want to - la la, la la la.  Okay, so I don't know the words to the song but I do know bringing a dog or cat to a party needs to be approved first by the party host.  Double check the front of the party invitation, who was it addressed to?  Did it include your pet?  If not, then a friendly chat with the host should be done before bringing your animal.  It is an easy oversight, even if the invitation was engraved, to forget inviting a pet.  So use kindness when speaking with the host. It is not recommended asking the host if your pet can come to a few types of events like a wedding,
baby shower,
baby naming
party or bridal shower
.  Once the host agrees to your pet coming to the party, there is a few simple rules of etiquette to follow.

    First, be sure to have your pet brings the hostess a gift, like gift baskets
or flowers.  In addition, bring the hostesses pets party favors. 
Next, bring along extra pooper scoopers.  Have your pet dressed appropriately like wearing a bandana or
Halloween costume.  If it is a theme party like luau,
Mardi Gras,
Super Bowl,
Christmas, Hanukkah, or other
holiday choose a festive matching pet outfit.  Animals tend to have different diets, so bringing along pet food and bottled water is a good idea, too.  Be thoughtful by bringing your own bowls and placemat for when your pet dines.  Your pet should not rely on the hostess for any special
requirements.  So, don't expect the hostess to provide your pet with a
party favor.  Although the hostess might invite your pet, not all hostesses will think ahead of time about having party supplies for your pet,
too.  Thus, prepare your pet for any possible disappointment.  Remember, glow sticks
are not pet friendly party favors.