Bottom Discoloration and Itchiness

Hello,

My dog's anus has a rash that has turned black in color (from the usual pinkish). It itches him.
What is this and what can be done?
Thanks

[Cliff Redford, DVM]

skin rashes can be due to simple infections, fungal disorders, autoimmune disorders, allergies, parasites such as mites....the list goes on and on. The darkening of the skin is simple related to the trauma that is occurring from excessive scratching or licking. Your vet will need to see your dog to determine the cause of the itchiness. Once the primary cause is treated then the skin colour should slowly return to normal.