
If you didn't feel sad it wouldn't be normal IMHO.
When I collected my bitch Jessie from her breeder(Jessie was 14 months old)she couldn't watch me drive away even though she knew it was the best this for her(long story) & when I collected Jessie full brother Wukee, her partner always puts the puppies into the new owners car & then rushes indoors to cry. they both say the day that they stop being upset is the day they will no longer own dogs.
I bought a BC puppy for a friend in Germany & knew that she would be going away from the day I got her, yet when she happily went off with her new owners to the ferry I had to turn & walk away quickly as i was so upset & this puppy was not related to my dogs at all.
Wukee & Jessie's breeders know that the four puppies that have left them from this litter are in good homes & they are forever homes, but they still care about them as all good breeders should.
Can't say that about the breeder of my cavaliers, they never even bothered to contact my friend when her dog died suddenly, they were simply breeding for money & the kudos of producing winning show dogs