HYPERADRENOCORTICISM (CUSHING’S DISEASE)
SIGNS
Cushing's disease is an overproduction of a hormone (cortisol) which produces the signs of excessive drinking and urinating; the veterinary term is hyperadrenocorticism. Cortisol is produced by the adrenal gland, and is usually released during times of stress (i.e. fear). The cortisol alters the metabolism, preparing for ‘fight or flight’, by releasing fat, sugar and keeping in water/sodium. When this occurs over time, your pet’s body is seriously affected resulting in many of the clinical signs, such as muscle wasting.
Cushing's disease is most often seen in small breed, older dogs. The biggest clinical signs are increased drinking and urinating excessively. Most dogs have a distended, swaying belly; the excess cortisol causes loss of abdominal muscle. Many dogs have skin changes seen as hair loss and a sparse hair coat, at times the hair loss is symmetric. In most dogs there is an increased, appetite, and excessive panting. These dogs typically have been tested for other causes of increased drinking (including diabetes, kidney and liver disease) and all tests have come back negative.
CAUSES
The most common cause is due to a tumor on the pituitary gland (a gland at the base of the brain). A small percentage of cases are caused by a tumor on the adrenal gland (a gland in the kidneys). In some cases, pets can get all these signs by being on steroids, such as prednisone. In this case, the treatment is to wean the pet off the drug.
The most useful diagnostic test your veterinarian can perform is called the low dose dexamethasone suppression test. This is the most accurate in confirming Cushing's disease - about 90% of dogs will test positive. Normally if you give dexamethasone to a healthy dog, the pituitary gland will sense this, and you will see a drop in blood cortisol. In a dog with Cushing's disease (usually a pituitary tumor), there is no drop in blood cortisol 8 hours after giving the injection.
The major part of diagnosis is differentiating between pituitary Cushing's disease, and adrenal tumor as the cause. This is important to know, because treatment is very different for each type. If there is an adrenal tumor is present, there is a 50% chance of it being a malignant; surgery is an option in that the tumor may be removed. If the cause is pituitary, then medical options are the treatment of choice.
SOLUTIONS
TO THE VET. If your pet has some of the signs of Cushing’s (excessive drinking and urination) then it is first important to rule out other diseases. Your vet will check for diabetes, kidney disease, and liver disease. A general blood screen will be suggestive of Cushing’s. At this time, they may recommend further screening tests and discuss traditional treatment.
CONVENTIONAL MEDICATION. There are primarily two conventional options to consider in treating your dog for Cushing's disease. Lysdoren is an older, cytotoxic drug which destroys part of the pituitary gland. It has serious side effects, and if given as an overdose it can give your dog a condition called Addison's Disease. Trilostane is the newer drug that is treating dog Cushing's disease with fewer side effects. It works by inhibiting adrenal enzymes, lowering the blood cortisol. Both drugs require that your dog take them regularly, and that there is regular monitoring by your veterinarian.
CURCUMIN. This herb is found in the spice turmeric, and recent studies have shown is may be very helpful for this disease. The study was titled:
'Growth suppression of mouse pituitary corticotroph tumor AtT20 cells by curcumin: a model for treating Cushing's disease.'
The authors concluded:
'The ability of curcumin to inhibit NFkappaB and induce apoptosis in pituitary corticotroph tumor cells leads us to propose developing it as a novel therapeutic agent for the treatment of CD.'
The study is here: https://www.ncbi.nlm.nih.gov/pubmed/20405005
The dog curcumin dose is 100mg/10lbs once or twice daily of the 95% curcuminoids. They can be ordered from pharmacies, on Amazon, but must be given with food/fat to be absorbed.
If I were to have a dog with moderate signs of Cushing's disease, I would be inclined to try the curcumin first. | 
