Whereas, ragweed pollen could be a problem in late summer and early fall. ??? When pollen grains are in the air and the inhalant allergies occur, the dog will bite and scratch his body, shake his head, lick his paws, shake his head, and rub his face on the carpet or grass for relief. ??? Inhalant allergies can also be caused by household dust, mold spores, and other irritants.