Itching and scratching in a Rottweiler

Where is he itching? Is there any hair loss or flaking anywhere? Any other skin lesions? Certainly allergy is a big cause for itchiness, but all other causes such as skin parasites need to be ruled out first.

What do you feed, and what do you use as treats?

Thanks for your re: You wrote. To answer
your questions no his skin flakeing,no
lesions but, there is hair loss on his
back. The food he eat's is as follows
Pro Visoins,pro plan dry mixed with hot
water once a day. His treats are called
Team Treats dog biscuits. As you know
our vet is treating him for allergies
with a needle and type of strroied pill.
The needle does not do much but the pill
stops the iching but also knocks him out.
When on this pill he wets the floor,
he can never get enough water, he just
not right.
If he responds fully to the steroid (stops itching altogether) then you should think about starting a fatty acid-antihistamine combination which will allow you to wean him off the steroid (which is the reason he has such a tremendous thirst, and of course the more he drinks, the more he will urinate).

I find a combination of a product called EFA-Z+ and hydroxyzine work well, but I'm sure that your vet has some combination which he uses. In either case, start the fatty acid-antihistamine, and supplement this with four 1,000 mg fish oil capsules per day (reduce to two/day after two weeks).
I also usually treat my itchy patients homeopathically. Allergy is basically a hypersensitivity of the immune system. Once balanced, the allergic triggers don't cause a problem.