Dear Most Esteemed and Knowledgeable Kitties:

My 18-year-old cat had a dental cleaning and 3 premolar extractions from the upper jaw two weeks ago. She seems to be healing nicely and is eating well again. However, she has developed a strange habit after the surgery that she didn’t have before: she has started frequently curling her left lip up in a “sneer”– almost exclusively her left lip. I asked the vet and he said it was a smelling reflex, but she never did this before, and she doesn’t seem to be smelling anything in particular when she does it. Has anyone else ever experienced this?

~ Tiffany

This cat’s sneer could be due to the fact that he’s smelling some pheromones. On the other hand, he could just be copping an attitude! Photo CC-BY-SA by Hilary Perkins

Siouxsie: The smelling reflex your vet is referring to is known as the flehmen (pronounced FLAY-mun) response, a special way that cats — and horses, goats, tapirs and lots of other critters — “grimace” to enhance the scent of pheromones.

Thomas: Pheromones are natural chemicals that creatures of the same species use to send messages to other creatures of that species. So don’t worry if you can’t smell what your cat is responding to; it’s totally natural that only she can smell it.

Bella: Or maybe she smells something stinky, like I do when Siouxsie makes a poo!

Siouxsie: Do I have to come over there and smack you?

Thomas: Bella, be nice to Siouxsie. Now, come on!

Bella: Oh, okay … spoil-sport.

Siouxsie: Anyway, as I was saying before I was so rudely interrupted … the flehmen response is built into kitties. The grimace or sneer a cat makes when she smells pheromones allows air to pass close to a special scent organ called the Jacobson’s Organ, located between the nose and the mouth, which has receptors for those pheromones.

Lioness exhibiting flehmen response, CC-BY-SA by Joxherra Aihartza

Thomas: Many cats exhibit the flehmen response when they smell catnip, honeysuckle, or the urine of tomcats or female cats in heat.

Bella: If your cat is having a flehmen response for the first time you can remember, it’s possible that having had her teeth pulled and the pain treated is allowing her to use her full range of smell sensors again.

Thomas: The thing is, the flehmen response is usually a full sneer or grimace, not just a one-sided expression.

Bella: It’s possible your vet isn’t fully understanding what you’re trying to explain about your cat’s sneering. On the other hand, it’s possible we’re not fully understanding, either.

Siouxsie: You might want to get a photo or some video of your cat displaying the behavior and share it with your vet. That way your vet will be able to see exactly what you’re talking about and will either be able to reassure you that your cat is exhibiting a flehmen response or ask you to come in and have your kitty’s mouth looked at.

Thomas: This is actually a great tip for anyone, because as you know, we cats can be pretty contrary and stop displaying the behavior that made you want to call the vet once you get to the clinic — and then you look pretty silly worrying about what seems to be nothing at all.

Bella: Photos or video can also allow your vet to observe the behavior or symptom without worrying that he or she doesn’t understand what you’re trying to communicate.

Siouxsie: We hope this helps, Tiffany. Please let us know how things turn out.