Dogs are a species in Adventure Time.
The dogs in this world for the most part have been shown to be a specific yellow- or orange-colored breed of bulldog and have many attributes akin to real dogs. They have increased senses such as sight and smell compared to humans and most have shorter life spans due to living in "dog years." It's unknown whether dogs with magical powers such as Jake have different life spans. Dogs have adapted and evolved to the circumstances of the world they now live in. They have become anthropomorphic and gained the means of speech as well as the usage of tools and weaponry akin to prior humans.
Other dogs may have gained supernatural attributes. These include various magical powers such as being able to change their size and mass, as well as communicate with one another in dreams.