A dog’s skin can darken for a variety of reasons. Proper diagnosis requires careful observation by you and a skilled veterinarian. A veterinary dermatologist may also be consulted.CallusesDarkening of the skin in a crease or on an area of the body that comes in contact with the ground may be normal callusing. As a puppy grows, the skin in these areas roughens, hair falls out and skin darkens. This protects the area from friction.InfectionsDarkening of the skin may be caused by bacterial or fungal infections. These infections also cause pus or discharge, cracking, flaking, foul odor, blistering, scabbing or bleeding.AllergiesAllergies to food or medication are also suspect. In terms of food, corn and milk are common allergens.Diseases and ParasitesDarkening of the skin is a symptom of hypothyroidism and some autoimmune diseases. Mites, fleas and lice can also cause skin irritation. These are accompanied by scabs and sores.Sunburn and Contact DermatitisA dog’s skin may darken from sunbur
It is called hyperpigmentation. It is not a specific disease but a reaction of a dog’s body to certain conditions. The affected areas will go away on their own only after identification and treatment of the underlying cause. My advice is to address a vet. My dog had this problem because of an allergy. All I had to do is to give her a prescribed medication that I bought at Pet Pharmacy. Everything is fine now.
I prevented my dog from darkening that area, using some things more than anything physical means and bought a wheelchair for disabled pets on a page so that it would not hit the back part to the ground and it would not become calloused. I don’t know if it’s because of her genetics, but that’s how it worked for me.