Great article. My goldendoodle ( yr) used to have frequent wet dermatitis until I switched to a prescription food high in fish. Last week, however he developed a spot on his leg that I could not manage with homeopathics (Florasone Cream) and triple antibiotic ointment. I took him to the vet (my regular vet was out) and he gave him a shot of Dexamethasone. It has been a bad experience. Extreme thirst, such frequent urination that I had to take him out all through the night every two hours. Panting. He is losing a lot of hair when I brush him, as well. I had asked the vet if I could expect frequent urination and he said no and did not inform me of any other side effects.
The spot is not improving, either. He is wearing a e-collar during the day but can’t sleep with it, so he licks it at night. Any suggestions are appreciated.
As a glucocorticoid , the lipophilic structure of prednisolone allows for easy passage through the cell membrane where it then binds to its respective glucocorticoid receptor (GCR) located in the cytoplasm. Upon binding, formation of the GC/GCR complex causes dissociation of chaperone proteins from the glucocorticoid receptor enabling the GC/GCR complex to translocate inside the nucleus. This process occurs within 20 minutes of binding. Once inside the nucleus, the homodimer GC/GCR complex binds to specific DNA binding-sites known as glucocorticoid response elements (GREs) resulting in gene expression or inhibition. Complex binding to positive GREs leads to synthesis of anti-inflammatory proteins while binding to negative GREs block the transcription of inflammatory genes. 
Hypoadrenocorticism is treated with fludrocortisone (trade name Florinef)   or a monthly injection of desoxycorticosterone pivalate , DOCP (Percorten-V or Zycortal)     and daily prednisolone . Routine blood work is necessary in the initial stages until a maintenance dose is established.  Most of the medications used in the therapy of hypoadrenocorticism cause excessive thirst and urination. It is absolutely vital to provide fresh drinking water for a canine suffering from this disorder.