What is what does it mean when a cat opens its mouth at you?

When a cat opens its mouth at you, it can mean a few different things, and the context is key to understanding the behavior:

• Flehm Response (Lip Curl): This is perhaps the most common reason. The cat is processing a scent, often related to pheromones. They open their mouth slightly and curl their lips, drawing the scent over the vomeronasal organ (also called the Jacobson's organ) located in the roof of their mouth. This organ enhances their sense of smell, allowing them to "taste" the air. It's not an aggressive behavior.

• Confusion or Curiosity: Sometimes, a cat might open its mouth slightly if it's puzzled by something you're doing or saying. It's like a "what?" expression. The mouth might be slightly agape, and they might also be tilting their head.

• Respiratory Issues: Open-mouthed breathing, especially if it's accompanied by panting, wheezing, or labored breathing, is a serious sign and indicates a possible respiratory problem. Get your cat to a vet immediately. This could be due to asthma, heart failure, or other medical emergencies.

• Discomfort or Nausea: If a cat is feeling nauseous, they might open their mouth slightly and drool or gag. This can be related to eating something bad or having an underlying health issue.

• Post-Spraying or Marking: Similar to the Flehm response, but sometimes seen directly after spraying or rubbing against something to deposit their scent.

Consider the overall body language of the cat. Are its ears forward or back? Is its tail twitching? Is it relaxed or tense? These clues, along with the context of the situation, will help you determine why your cat is opening its mouth.