My dog has black crusty patches on her back legs. What could it be?

I am sorry to hear about Freckles. The black crusts could be flea dirt, which is digested blood left behind by the fleas (if you place it on a paper towel and wet the black debris and it turns a rust color then it is likely flea dirt). We can also get skin infections resulting in crust and debris in dogs. I would recommend an examination by his vet if he is very itchy. He may need oral medications, or a topical treatment such as a medicated shampoo like Duoxo Chlorhexidine may be needed.

We commonly see an overgrowth of normal bacteria on the skin cause crusting and scabbing. When this happens around and in the hair follicles, the hair will easily fall out. When a dog has a thick coat, the crusting can spread under the coat and go unnoticed. From your picture, it looks like this area may be over the hip/pelvis. In older dogs, when their bones are more prominent, they will sometimes have areas like that due to lying on harder surfaces. These can become pressure sores, so be sure to keep an eye out for those. I agree that the area does not look irritated, but there is still some brown crusting left, so be sure to monitor the area closely for any spread of the crusting. If the crusting spreads or the skin appears red, be sure to have your vet evaluate the area. Good luck! I hope that was helpful. Thanks for using Petco Pet Education Center, formerly Petcoach.

The most common reason that we will see circular or semi-circular rings or crusts in a dog is a superficial bacterial skin infection. These areas typically start as a small bump which ruptures and forms a crust. That crust can spread and form a large area of hair loss with crusting around the edge. We can also see fungal infections that will have this same behavior. In order to determine what is causing the problem, your vet can so some simple skin tests and look at a sample under the microscope to make a diagnosis and determine the best treatment for Cooper. There are topical medications like wipes and shampoos that we will sometimes use or other times an oral medication is needed. Good luck! I hope that was helpful and answered your question. Thanks for using Petco Pet Education Center, formerly Petcoach.

It's possible your pet is experiencing symptoms of a bacterial infection due to mange mite infestation. You'll want to be sure to visit your local Veterinarian as soon as possible and request a skin scraping examination. This will allow your doctor to identify the underlying cause of your pets discomfort. You're doctor may prescribe an antibiotic to help stop the infection and mite/mange treatment if needed.

This is probably due to a severe allergy, although it could also be fleas or mites. First of all, in order to rule out skin parasites, you will need to treat Katie with a high quality flea treatment (e.g. advantage), then get her to the vet to perform a skin scrape - this might reveal an infection or a mite infestation. If all of those came back negative, the next step is to treat the allergy symptomatically and try discovering the cause of the allergy. Some medications can be given by the vet in order to repair the skin lesions (steroids and antibiotics). simultaneously you should start her on a prescription hypoallergenic diet for at least 2 months. Hopefully you will see some results after all this, if not you and your vet should consider putting her on a long term allergy treatment (Atopica or Apoquel).

Hi. Thanks for the photos. There are a few common things that can cause the dark coloring, hair loss, and even itching. The most common can be allergies. Others would be deep infection, parasitic, low thyroid, and hormonal imbalances. With the photos here and the severity, I am highly suspicious of severe allergies or low thyroid level. I would make an appointment with your veterinarian when you are able and they will do a full exam. They will do some skin testing, bloodwork that will include thyroid levels, and whatever medication may be needed depending on the probable cause after an exam. Good luck

In your picture it looks like there might be a small skin growth in the center of the ring like skin lesion, so if there is still a raised area I would recommend seeing your veterinarian. Some skin growths are benign and can be monitored while others should be removed. The areas of crusty debris could be from trauma, or potentially an infection secondary to allergies. If these areas do not improve in the next few days or if new skin lesions develop I'd also recommend seeing your vet.