Graciela
Frost
Some dogs drool when you take them out for walks. The major condition of this is Hypersalivation lies galore, the one being excessive production of saliva in the dog’s system, which is known as Ptyalism. The reasons for excessive production of saliva can be caused due to Rabbies, nausea (does your dog puke while taking a walk, if it does, then please consult a vet). Another condition which can really also be the reason of Hypersalviation can be Hepatic Encephalopathy which also makes the dog salivate excessively. It means that the liver is not working fine.
Another reason for salivation may be the side effect of some medication like Soloxine or Sucralfate. But the cause of salviation is different in your case. I think it must be behavioral for your doggie pal to salivate like this in public. Try to take your doggie pal with you in some place outside your home, like a friend’s place and see what happens! If she does salivate over there also, then it means it is behavioral for her.