Josie (our Chocolate Lab pup) cushings is caused by a tumour in her pituitary gland (not sure if that is good or bad).
The pituitary gland is located in the brain stem and over here in the US is considered pretty risky surgery. As Cushing's is seen in more in older dogs it may be more of an age thing but brain surgery is usually pretty complicated.
The pituitary gland is a clump if sensors and switches that monitor blood content. When it determines cortisol is needd it sends a signal to the adrenal glands to produce what is needed. In pituitary Cushing's the tumor plays the role of the bully, dolt, or oaf that leans aginst the control board, continually pressing the switch that calls for cortisol. The adrenal glands respond by producing cortisol 24/7 (twenty-four hours a day/ seven days a week.) The tumor is generally very slow growing and at least in older dogs is not the primary cause of death.
The body needs a certain level of cortisol to function properly. The amount fluxuates depending on the activity. Stress increases the need. Too much cortisol produces a toxic effect on joint tissue as well as muscle mass, and also attacks the organs. It also messes up the coat. Many symptoms of Cushing's are shared by other diseases.
Beware of staph and yeast in infections. They can produce hard, *****, dark coloured nodules, and hair loss.
Misty was a rather chunky Labrador when she came to live with us, weighing 81 pounds. We had been able to get her down to about 76 pounds over about two years when she started to shed weight and hair rapidly. She went from 76 to 64 pounds in five months, started drinking water until she was consuming over three gallons of water per 24 hours, had UTIs, and dilute urine.
Be sure to monitor water input/output and note any sudden changes as well as subtle trends. If the meds used to control cortisol block too much production, stress could produce an Addisonian crisis wher ethe body uses up all available cortisol and causes collapse.
Even though Misty likes the vet's it is stressful and even though water intake did not appear low, she collapsed at the vet's during an exam and presented life threatening symptoms: comatose and very low blood pressure. Fortunately she was at the vet's when it happened othewrwise she would have died.
Some vets believe it is simplier to treat an Addisonian dog than a straight Cushing's case and will induce Addison's.
Cushing's also messes up temperature control. Increased panting is a symptom of the disease.
Learn as much of the disease, treatments and medicines used, and the side effects. Diet may play a role so do research different feeds and talk to people.
Please keep us posted on how she is doing. PM me if I can be of further assistance.
HTH