
I use Kelp (seaweed powder) in my dogs food just a little bit, that helps with the pigmentation. All mine have nice black noses etc.
What breed is your dog, sounds like the poor wee thing has not had a very good start especially with parvo glad you managed to get that cleared up as it can be fatal.
Some one else will be along soon to give you some more advice as you are asking about things that I have never experienced , so cant really answer the rest of your questions.
Good luck with the puppy anyway.