I have been using one of the top dollar $35.00 per single monthly dose flea and tick repellant on my dog. Hes not getting wet after the application and im applying it per single drop wise between his shoulder blades and down his spine to his hips. Im also rubbing a very minute amount between my finger tips and massaging the backs of his ears with it. Trying not to get it too close to his eyes, nose and mouth. The first week after the treatment he is fine but right into the second week the deer flies are biting his ears to the point the hair is gone and the tips are crusted thick with dried blood. What can i use now?

I thought about rubbing permethrine on the tips of his ears but that might be a bit too much for him.

Could i possibly use white diaper rash salve and add cornstarch to it and make a paste that maybe the flies cant bite through and apply it to the tips of his ears daily.