It does kind of look like leather ear but the leather ear could be as a result of all of her scratching....and that is most likely due to ear infection and/or ear mites. As dirty as you say they are I suspect ear mites and an infection. Definitely get her checked by your vet, to get proper meds for the infection and ear mites.
With treatment and getting the scratching to stop along with warmer weather, her ears and nose will get better (grow hair) most likely.
One of the foster girls I have has had leather ear, since she's been treated for infection and is getting proper grooming her hair is coming back and she's been here about a month.
__________________  ~Ruby, Reno, Razz, & Jack~ |