Edge of dogs ear - loss of hair and dry

I have noticed that on the very edge of both of my dogs ears there is some hair loss and also dry skin. There has been no bleeding or open wounds, it doesn’t not seem to be irritating him at all he is not scratching or shaking his head. He is a 2 and a half year old Staffordshire Bull Terrier. 

Hello!  I wonder whether there could be demodex mites present.  Most mites are itchy, but not demodex; they burrow into hair follicles, causing tiny swellings and baldness.  Your vet would be able to rule Demodex in or out with a series of deep skin scrapes, which can often be done in the space a long consultation.  Often, the fact that demodex have managed to proliferate implies underlying illness, so if that's the case then they may then go on to test for other things.  Other possibities are many and varied, including an early sign of endocrine disease, yeast infection, ringworm etc.  It's definitely worth a trip to your vets at this early stage.