Hi Jennifer. I am sure Marianne will have some input for you when she has time to check in but I wanted to address your question about the DDAVP injection based on my own experience. DDAVP is a synthetic form of the anti-diuretic hormone (ADH) which regulates the amount of water in the body and increases sodium and water absorbed by the kidneys. It is rare that a dog being treated with Vetoryl does not see a complete resolution of excessive drinking and peeing but a small number of dogs will still have an ADH deficiency. If this were to be your dog's problem, DDAVP would likely be effective. My second cushingoid dog was a shelter rescue so I knew nothing about his history. Unfortunately, his excessive drinking and peeing never resolved with trilostane or mitotane treatment despite excellent control of cortisol His urine specific gravity (USG) never improved and stayed at a pretty consistent 1.008 which is quite low. If your vet is suggesting DDAVP, I have to assume your pup's USG is also below 1.015. Unfortunately my dog did not respond to either the DDAVP eye drops or pills so he was ultimately diagnosed with nephrogenic diabetes insipidus. To correctly diagnose diabetes insipidus through testing, a water deprivation test is done but I did not want to subject my dog to that so we did a trial with DDAVP. That is what most vets recommend so there is no reason why you can't give it a try. If there is an ADH deficiency, a dog usually responds quite quickly. I hope this helps.

Glynda