Hi Sir or Madam,
What areas are turning this color?
Is she licking these areas?
How large are the areas?
Any scratching or hair loss?
Any odor to the skin?
The pinkish brown area started on her front paw. I do recall her licking that area. Now the discoloration has progressed up her leg and onto the back area. There is no odor and no hair loss.
Most likely this is caused by her saliva. Dog tears and saliva contain an enzyme that causes a chemical reaction on the hair turning it reddish brown. There are many products on the market to remove this. They are marketed as Dog tear Stain Removers. This discoloration is frequently seen around the mouth, on the paws and under the eyes. Other areas are places the dog can lick.
The website below has a different approach suggesting altering your dog's pH levels to prevent the staining which you may wish to look at.
There is also an antibiotic that your vet can prescribe called Tylan that has been shown to be useful to stop tears and saliva from discoloring a dog's coat. You will want to ask your vet about this.
Now there are medical conditions which can lead to skin discoloration such hypothyroidism and reoccuring skin dermatitis leading to thickening and discoloration of the skin. I hope this information is helpful to you.
Vet's do not routinely check for thyroid problems unless symptoms are present. With thyroid problems we usually see some hair loss and possible change in behavior. With a skin dermatitis, we usually have an oder and itching associated with it. However, if the dog has a history of skin problems the skin darkens then as well. Two common ones are staph dermatitis or yeast dermatitis. Staph usually occurs on the lower regions of your pet and tends to have small pimple type bumps. Shampoo containing Chlorhexiderm and/or Oatmeal can help with this condition. Yeast typically shows as a greasy area that has a sweet musty odor. Sometimes the skin can become inflamed, darker and thickened due to itching. Yeast likes areas such as between toes, armpits and ears. Selsun Blue Shampoo can help with Yeast dermatitis. When shampooing, lather and leave on 15 minutes before rinsing.
It might be dermatitis related to allergies, but they can occur without allergies. Anything that causes a dog to scratch can damage the skin and lead to a dermatitis. There is black skin disease as well, but usually there is hair loss associated with this as well.
You might also be seeing the start of one of these conditions and it hasn't progressed to the point of hair loss being present. If this was my dog, I'd try the selsun blue shampoo and the stuff for tear stains like angel eyes and see if that helps. If it doesn't seem to improve, then you will need to consult your vet so skin scrapings can be done .
One thing I failed to mention is that flea dirt can cause the skin to appear a pinkish brown as well though we usually see this in the areas where fleas are like armpits, abdomen and in front of the tail. Shampooing might rid the area of the color, but it will come back if the fleas are still present.
Flea dirt is how we refer to flea excrement which is mostly dried blood and is brownish until slightly wet and then becomes a pinkish brown color and can stain the skin. And fleas are very fast and you seldom really see fleas. To check for this, take a paper towel and wet it lightly. Rub it in the area and if you see pink on the paper towel, then fleas may be the cause. A good vigorous scrubbing with shampoo should remove most of it if this is the case.
With black skin disease it gradulally darkens and can start out brownish before going darker. But as I mentioned, there is usually hair loss associated with it as well.