There is a natural treatment for Cushings that I found for my dog. It's called Suprglan and I bought it online from Petwellbeing.com
This is what the website states: Supraglan uses natural ingredients to lower your dog’s adrenal system from a hyperactive functioning state, slowing overproduction of corticosteroid hormones. Supraglan is designed to restore your pet’s quality lifestyle and to increase life expectancy by reducing thirst and regulating elimination (liver/kidney and digestive); balancing blood Sugar levels (endocrine); increasing muscle use and ability (anti-inflammatory); protecting against infection (immune); and by promoting a healthy skin and coat (natural herbs)
It certainly helped my dog and now I recommend it to anyone who is facing Cushings with their own beloved dog.