Discoid Lupus Erythematosus (DLE) in Dogs
Dogs nose around in all sorts of things but they should not get crusty or ulcerated noses. When they do, there is generally a disease afoot and biopsy may well be needed to determine what is going on. Discoid lupus, or DLE, is a common disease of the leather of the nose. Thankfully, it is usually easily treated and there are many options.
Discoid Lupus Erythematosus (DLE) in Dogs: https://veterinarypartner.vin.com/doc/?id=4952581