I agree that "winter coat" should be added.
The first definition of "pelt" in Oxford Dict. of Eng. (not the OED but big!) is "the skin of an animal with the fur, wool or hair still on it" but it also has the definition "an animal's coat of fur or hair" so it is used for living animals, if not as often.
Also, "Fell" in German does not refer only to the coat of a living animal, so "pelt" would still be a good translation of "Fell". I can imagine that there might be a distinction made between "winter coat" and "winter pelt" if I was talking about a ladies' fur coat and said it was a "winter coat" that would just mean it was a coat for me to wear in the winter, but if I said it was a "winter pelt" that would mean it was an animal's white winter fur.
1. a) dicht behaarte Haut (eines Säugetiers):
b) (als Rohmaterial dienendes) abgezogenes Fell: -e gerben;
"This price will get you a mid fall, early winter pelt without feet. ..." http://www.facesoftheprairie.com/05furpelt.asp
"As the winter pelt was a seasonal item, most contracts specified payment in the spring or in a specific month, usually April but sometimes May or June. ..." http://www.coins.nd.edu/ColCoin/ColCoinIntros...
"Ermine in its original form is the winter pelt of the stoat, an animal which turns all white except for the tip of its tail. The fur was (and is) prized and ..." http://www.nyrond.org/university/heraldry/www...