Vet Brendon Bullen said that coeliac disease was possible, but very rare in dogs, gluten-free food would not do any harm providing it was part of a balanced diet.

She added that gluten-free pet food means it was free of grain, and was often an extension of that lifestyle choice. Auckland dog owners Sherryll Foot and her daughter Maddie Kinsman invested in gluten-free food for their pet dog Daisy and saw that she was certainly sleeping a lot better and her skin seems to be in a better condition.
Vet Brendon Bullen of the Companion Animal Society said that coeliac disease was possible, but very rare in dogs, adding that gluten-free food would not do any harm providing it was part of a balanced diet. He added that a sales factor might be that some humans who do have a sensitivity were recommended to have a gluten-free household, and of course pets were part of that.
Source-ANI