Zoos and parks used animals for advertisements, and business did the same thing. To this day, businesses use animals for their ad campaigns no matter the medium -- whether it is TV or print -- to sell their products to customers. In some cases, artists such as Ryan Fowler created fictional companies named after animals to create fake ads. These prints were similar to ads as they are promoting a fake product.
Art Nouveau artist Theophile Alexandre Steinlen used cats in some the prints he made. Many of Steinlen's designs were advertisements for clubs, shows that were happening around Paris, and a few hotels. Steilnlen's work is an example for both the vintage animal poster art that interest people and the fact that many of these prints were once advertisements.