my dog is a beagle-Bassett hound, she sheds alot! and she is always really itchy...
There are several reasons that your dog could be itchy including: parasites, allergic reaction, and hot spots.
First I would check to ensure that your dog does not have any hot spots, fleas, or ticks. Allergies, however, can only be determined by your veterinarian. You may wish to consult with your vet before starting any treatment.
Then, you can try an anti-itch Shampoo or anti-itch medication