I have a 5 year young border collie lab and she has these episodes where she starts licking/salivating, sometimes lip smacking occurs. Episodes last about 1-2 hours. Her heart rateia normal 69-80 bpm. Her breath doesn’t stink. I brush her teeth daily. Pupils are responsive (no epilepsy or seizures, she doesn’t lick the air just her mouth) She has had a general blood test done. Her kidney/liver function, electrolytes, thyroid, hormones, and her Red and White blood cell count were all normal. Test results were all normal.