Cushing's disease manifests in dogs as increased urination, thirst, hunger and panting, according to petMD. Obesity, hair loss, lowered energy levels and insomnia are also common. Female unspayed dogs may no longer go into heat, while male unneutered dogs may have shrunken testicles.
Cushing's disease also affects the skin, explains petMD. The skin darkens and may appear as though it is covered in blackheads. As the dog gains weight, the skin becomes thinner and more prone to bruising. Finally, hard, white, scaly patches appear, often on the elbows.
Cushing's disease occurs when the pituitary gland increases cortisone production, usually due to the presence of a benign tumor, states petMD. Rarely, the tumor is malignant and metastasizes, spreading throughout the body. Cushing's disease is usually treated with surgery, but if this is not possible, drugs are used instead; however, the drugs have severe side effects and the dog may require close monitoring. Owners are recommended to watch their dogs and observe any changes in behavior, including vomiting, diarrhea, appetite loss, weakness and difficulty walking.
Cortisol is an important hormone for dogs, notes WebMD. It is responsible for helping the dog's body respond to stress, control weight and maintain the immune system. Cushing's disease can be fairly difficult to diagnose, with no guaranteed method available as of 2015.