* Ringworm: This is a fungal infection that can cause hair loss, scaly skin, and green patches on the skin. Ringworm is contagious, so it is important to take your dog to the vet if you think they may have it.
* Mange: This is a skin condition caused by mites. Mange can cause hair loss, scaly skin, and green patches on the skin. There are two types of mange: sarcoptic mange and demodectic mange. Sarcoptic mange is contagious, while demodectic mange is not.
* Bacterial infection: A bacterial infection can cause hair loss, scaly skin, and green patches on the skin. Bacterial infections are often caused by bacteria that enter the skin through a break in the skin, such as a cut or scratch.
* Allergic reaction: An allergic reaction can cause hair loss, scaly skin, and green patches on the skin. Allergic reactions can be caused by a variety of things, such as food, pollen, and dust mites.
* Cancer: In rare cases, hair loss, scaly skin, and green patches on the skin can be a sign of cancer. Cancer can affect the skin directly, or it can cause changes in the body that lead to skin problems.
If your dog has spots with no hair, white and scabby skin, and green in the middle of it, it is important to take them to the vet to determine the cause. The vet will be able to recommend the best treatment for your dog's condition.