Cat Drools When Petted. This is not uncommon and merely indicates a physiologic response to happiness. When your cat is drooling whilst you’re petting her, you should take it as a compliment.
Pets overload says cats can start to drool when their stomach is being rubbed for a long time. If your cat drools out of apprehension it will not persist. Because they are happy and relaxed, some cats drool when petted.