I would like to know what illness my princess has, a year ago she scratched her right ear, her right hind leg is stained brown and what she has is contagious because she already infected two dogs, scratches and shakes her head, the vet He prescribed some drops for possible animals such as mites but he did not help me, when the bathroom washed his ear and he did not scratch that day, his ear was shaved in Petsmart but it's still the same.
You should go to your vet to explore Princess and determine if there is something that is generating pain and discomfort. It could be a wound or ear infection (otitis), or even some neurological problem.
If it is otitis (ear infection), the vet has to determine if it is just external or if it has moved into the inner ear.
In both cases, your veterinarian will give you corresponding treatment and indications on how to keep your dog's ears clean in order to prevent infections.
If your dog gets often ear infections, it would be necessary to do a mycobiological culture, cytology and contemplate the allergic factor, to determine the origin of the otitis and the most effective treatment, since many of the dogs with chronic otitis develop antibiotic resistance.
All the best