The major pattern companies have a few dog clothing patterns.
Butterick has a swing coat that I think (hope, even, as I intend to make Gracie one) would look great on a Doberman:
B4885 | Dog Coats | Crafts/Dolls/Pets | Butterick Patterns
You can obtain fabric laminate that irons on and it can be used to make any non-fuzzy fabric water resistant.
Vogue even has a dog-wear pattern, though it'll need altering for a dog more than 26" long:
V8312 | Dogs' Coat | Crafts/Dolls/Pets | Vogue Patterns
McCall's, including a roll up "go to place" mat:
M4686 | Pet Gift Items | Crafts/Dolls/Pets | McCall's Patterns
McCall's even has some occasional wear, including a sort of Santa suit, and in sizes that would fit even a Great Dane:
M6259 | Pet Clothes, Blanket In 2 Sizes And Sleeping Bag | Crafts/Dolls/Pets | McCall's Patterns
The biggest problem I have encountered with the patterns is that many are only sized for dogs considerably smaller than a Doberman. I've tried here to only link to patterns that are sized to fit at least a female Doberman (26" nape of neck to base of tail).
Meadow Cat, fleece is technically a knit fabric. Try a ball point needle, and do the usual things one does when stitches skip; new needle, clean feed dogs inside and bobbin and bobbin race & oil. You may need to fiddle with tension some as the fleece tends to be thick relative to most fabrics. I'd use a walking foot, too, if I had one. And fleece is generally polyester, so the thread should also be polyester. I'd try a stitch designated as good for knits, too. Good luck!
Tuxedo Jack, please do post a photo of this jacket you love.
And would someone, please, pretty please, post me a photo of the bikini styled bitches' britches laid out flat? Pretty please? I really think they're likely to fit a Doberman more comfortably than regular bitches' britches.