Carnival is underway in Rio de Janeiro with hundreds of block parties in full swing. But the fun is not exclusively reserved for humans. Their four-legged friends are also hitting the scene.

Called "Blocão," a play on the words in Portuguese for block party "bloco" and "cão," dog, it is organized by Marco Antonio Toto and an animal rights activist.

"This is the only pet friendly block party in the city where you can come with your dog and you know he is having fun, because if the owner is happy so is the dog," said Marco Antonio, who thinks it is not good for pets to be left alone during Carnival.

There are two "Blocão" parades in two different Rio neighborhoods - Copacabana and Barra da Tijuca - during the city's famous Carnival, where hundreds of owners and their best friends take to the streets dressed in similar and elaborate costumes.

"I always think about a costume and ask a seamstress to make it. This year she is parading as an Indian princess," said Nadia Rei who owns a five-year-old female Yorkshire terrier.

The "Blocão" even has a contest for best original costume. Dogs of all breeds showed off in a country where they exceed the number of young children. According to latest official numbers, Brazil has 52 million dogs, exceeding the number of children under 14 years old.

Celebrating its 18th year, this dog parade is becoming bigger and more sophisticated with every edition.

Buba, for example, a seven-year-old dachshund who has been parading since she was born, was dressed in a custom-made golden ballerina dress. Her owner Jessica Leal said she loves it: "We always dress her up for Carnival and every year she uses a different costume, and she enjoys it, she is cool with all of it."

Tails wagging, many dogs in Rio are having their share of Carnival fun and even the lyrics of their own samba song proclaiming this a true animal party for real party animals.