New Study Decodes Chemical 'Messages' in Cat Urine for Feline Identification
A recent study published in the journal Current Biology has revealed that cats use branched-chain fatty acids (BFAs) in their urine as unique chemical fingerprints to identify one another. Researchers found that unusual fat droplets in cat kidneys likely help maintain these distinct scent marks. While many animals use a combination of visual, audible, and scent cues, some, like insects and mice, rely on specific chemical signatures. The study investigated the 'flehmen response' in domestic cats, an open-mouthed expression used to draw chemicals into their vomeronasal organ. Cats showed this response less frequently to familiar urine samples but more often to new ones. By splitting urine samples into components, scientists identified BFAs as the key chemicals triggering the flehmen response. Each cat possesses a unique mix of BFAs, which remain stable for at least a day, providing consistent identifying information. These BFAs are stored in lipid droplets within the renal cortex of the kidney, a feature als... 
