Treating Black on Dog Skin

Reader Question: How do I treat and diagnose dark spots on dog skin that are only partially responding to treatment

Hi Dr. Coates,

I adopted a 10 pound dog about 5 months ago. She was a mother in a puppy mill so I don't have much history on her. I believe she is a border/cairn terrier with possible a bit of chihuahua. The vet estimates her to be about 3-5 years old. She has been in great health!

About two weeks ago I noticed two black areas on her sides. There was no hair loss associated with the skin color change. I took her to the vet, she shaved the areas to get a better look. Upon examination we found a total of 9 of these blackened areas! The vet did a woods test (negative), a skin impression (showed some yeast and bacteria), and a skin scrapping (which has shown no changes after almost a week). At the same time she scrubbed my dog with chlorahexidine.

The next day the spots appeared to no longer be dry and scaly. I went back and she gave me a chlorahexidine shampoo to use every day for the next week (which is over tomorrow). I also put Mandi (my sweet little dog) on a grain and poultry free diet (Inovia Prime) and started giving her one fish oil cap per day. The spots are still supple and appear healthy but are still black. (it almost looks like they are tons of little tiny black spots in a cluster).

HISTORY: no signs of flees or other obvious creepy crawlies. She does lick at her paws a lot.

Spots are located on her flanks (one on each side almost but not quite symetrical), one on chest, three down the mid-line of her back, one on head (above eye), one under chin, one on paw(where she often licks), one small one on her spaying scar.

PLEASE give me any feedback. My poor baby had such a hard life in the puppy mill and should not suffer or have anything wrong in her life ever again... I'm worried... Should I be?

Sincerly,

Mandi's Mom

Vet Suggestions for Treating Dark Spots on Dog Skin

Hello,

The dark changes to your dog’s skin could have a number of causes. It sounds like your veterinarian is being very thorough, so I recommend that you continue with her diagnostic plan. Negative skin scrapings would mean that demodectic mange is unlikely, though still not impossible.

I cannot tell whether you are waiting for the results of a fungal culture, but ringworm should definitely be ruled out with this test. The yeast and bacteria (as well as the partial response to chlorhexidine that kills these microorganisms) makes me think that infection is at least part of the problem, but skin infections in dogs tend to occur secondary to other problems so I suspect something else might be going on too.

Allergies are a common underlying cause of skin infections in dogs, but hormonal disorders like Cushing’s disease and hypothyroidism are also possible. Additional testing would be necessary to determine if a hormonal condition, allergies, or something else was playing a role here.

Mandi is lucky to (finally!) have such a devoted owner. Skin problems often take patience and perseverance to diagnose and treat. Keep working with your veterinarian and I bet you’ll succeed.

Regards,

Jennifer Coates, DVM