Distemper Vaccine

Question
Does the distemper vaccine "calm down" dogs or is it just for protection against the Distemper disease?

Answer
It's to protect dogs from canine distemper- which is becoming prevalent again. Canine distemper is almost always fatal to dogs, and they can get it at any age.

Why someone would think it would be to "calm down" a dog? That is confusing to me...