What Is That?! - Incisive Papilla

One of the most important topics studied in vet school is anatomy - as veterinarians, we need to know what is normal and what isn’t.

Most pet owners, on the other hand, haven’t spent countless nights studying every organ, vessel, and protuberance found on a dog’s body. So it’s understandable that when an owner notices a less obvious anatomic structure for the first time, they may become alarmed and rush their beloved pet to the vet, fearing the worst.

These situations have inspired a new series for our column called, “What is that?!”

Maybe you’ve experienced this scenario before -- your happy, fun-loving pet is playing and when she rolls on her back, you suddenly notice a firm, diamond-shaped lump on the roof of her mouth, just behind her front teeth. Panic bells start ringing.

But not so fast! This is actually a completely normal structure. It’s called the incisive papilla and every dog has one, though some may be more prominent than others. The incisive papilla contributes to the dog’s intricate and exceptional sense of smell.

A human’s primary sense is vision - we understand our environment best through visual pictures. Dogs, on the other hand, rely most heavily on their sense of smell. To put into perspective just how sensitive a dog’s sense of smell is, dogs have more than 200 million olfactory receptors. Humans only have about 5 million!

And it gets even more interesting. Dogs don’t just smell with their nose. They also have a vomeronasal organ, which helps detect chemical cues called pheromones. Pheromones are important for communication and passing social messages between dogs. The incisive papilla helps collect these cues and is connected to the vomeronasal organ.

So if you’ve ever lost sleep after noticing this bump on the roof of your dog’s mouth, don’t worry - you’re not the first and you won’t be the last! The incisive papilla is one of the most common normal anatomic structures that cause owners to scratch their heads and wonder, “what is that?!”