Persistent swallowing and Distemper

My dog was swallowing repeatedly last night, and she looked sort of stressed or scared.  She was also retching.  She vomited once, but it was only water with white bubbles.  She was eating her food, drinking her water and she was also playing with her toys and with me.  Took her to a vet (not her regular vet) and she said it could be distemper.

Upon arriving home from the vet, I found a small hairball inside her mouth and removed it.  Her persistent swallowing has significantly decreased although she still does it.  By the way, she hasn't been drinking a lot of water lately, and we have been giving her water thru a dropper.

She has complete vaccination.  She was given two 5-in-1 shots but missed her booster shot, so she was given another 5-in-1 and then her booster.  She's also been vaccinated against rabies and kennel cough.

Please help.  What could be wrong with her?  Could it really be distemper?

[Aleda M Cheng, D.V.M., C.V.A]

It is unlikely that your dog would have distemper if she has had a completed series of distemper vaccinations.  However, the disease would be possible if your dog were inadequately vaccinated.  

Distemper can be confused with other diseases that carry the same symptoms of fever, gastrointestinal and, neurological symptom involvement.  The infectious diseases,  leptospirosis, infectious canine hepatitis, and Rocky Mountain spotted fever can be mistaken for distemper.   Lead or organophosphate poisoning can also be mistaken for distemper.

Perhaps it would be best to bring her back to her prior vet or get a second veterinary opinion.