TL;DR: Drooling during relaxation is usually a normal sign of contentment in cats, but sudden changes or bad breath may indicate dental issues requiring a veterinary exam.
What causes my cat to drool when they are happy or being petted?
Many cat owners are surprised to find a damp patch after a petting session, but this is often a sign of extreme relaxation and contentment. Known as 'pleasure drooling,' this behavior is frequently linked to a cat’s kittenhood. Just as kittens knead their mothers to stimulate milk flow, many adult cats knead and drool when they feel completely safe and happy with their human companions.
When should I be concerned that my cat's drooling is an emergency?
Urgency Level: Low. If your cat has a long history of drooling during cuddles and is otherwise acting, eating, and drinking normally, this is considered a normal behavioral trait. It is not an emergency. However, if the drooling has started suddenly in an older cat, happens when they are not relaxed, or is accompanied by a bad smell, it may indicate a dental issue that requires a non-emergency veterinary appointment.
How does sharing a photo or video help a vet evaluate my cat's drooling?
- Capturing a clear photo of your cat’s mouth and gums allows a veterinary professional to check for signs of gingivitis, redness, or broken teeth.
- Providing a video of the drooling while the cat is purring helps confirm the behavior is related to happiness rather than nausea.
- Visual evidence assists in determining if the salivation is a normal behavioral trait or a sign of oral pain.
Clinical Context (Merck Veterinary Manual)
Drooling in cats, or hypersalivation, can be associated with excitement, fear, or nervousness. However, it can also indicate a more serious underlying cause, either local or systemic, that requires veterinary attention. Other causes include oral foreign bodies, neoplasms, injuries, infectious diseases (e.g., rabies), convulsive disorders, reluctance to swallow (due to esophageal irritation or obstruction, or GI stimulation from gastritis or enteritis), sublingual lesions (e.g., linear foreign body, tumor), tonsillitis, administration of medicine (particularly in cats), conformational defects (e.g., heavy, pendulous lower lips), metabolic disorders (e.g., hepatic encephalopathy, especially in cats, or uremia), and abscess or inflammatory conditions of the salivary gland. The possibility of rabies should always be eliminated.
Chapter: Neurology, Gastroenterology, Infectious Disease, Dentistry, Emergency, Toxicology
Source: The Merck Veterinary Manual, 11th Edition (Page 368)