About 5% of dogs with Cushing’s Disease have atypical Cushing’s Disease which as with typical Cushing’s disease may be pituitary or adrenal-dependent.
Some dogs with atypical Cushing’s, like your dog have problems in the adrenal steroid production pathway. This is because of certain enzyme deficiencies.
The lack of enzymes can result in the accumulation of cortisol precursors that end up being sent or shunted into other metabolic pathways.
With atypical Cushing’s, they are sent to stimulate production of sex hormones referred to as androgen biosynthesis. This is why your dog’s androstenedione is elevated.
Lysodren is the preferred treatment for atypical HAC as it effectively lowers cortisol, androstenedione, progesterone, and 17 OH progesterone hormone levels.
Lysodren is referred to as an adrenocorticolytic agent.
We use a low “induction phase” dose which is about half the dose used for typical Cushing’s and that alone in about 3 days reduces adrenal cortex hormone synthesis and sex hormone levels.
The reduction in levels of the sex hormones including androstenedione.
can be validated with blood work and occurs whether or signs of Cushing’s disease signs such as excessive water drinking improve or not.
Note that Trilostane although great with typical Cushing’s should not be used because Trilostane increases adrenal sex hormone synthesis and hormones including17 OH progesterone. Trilostane usually also increases estradiol and androstenedione.
Note that Melatonin has anti-gonadotropic activity, but it takes 3-4 months to see results and melatonin may not reduce androstenedione levels as it’s effect on adrenal
sex steroid hormone synthesis is negligible.
Be aware of the fact that dogs are not able to convert flax into the essential omega fatty acids EPA or /DHA, but the lignin’s do carry anti-estrogen activity and can lowers cortisol enzymes.
Ketoconazole, an anti-fungal agent also decreases androgen and cortisol enzymes.
I hope this information is helpful.
Dr Carol Osborne, DVM
Thank you, Dr. Osborne,
So, other than Cushing's, there is no other cause for elevations in this hormone. Am I understanding this correctly? If so, I am prepared to deal with that. My fear was that something else could be going on. So I will look for an 17b- hydroxysteroid dehydrogenase inhibitor via nutriceuticals for now.
When Squirt was first diagnosed I wanted Trilo for her but as I have learned more, that drug will be the last resort for her..even if she develops true Cushing's, Trilo will not be used on her unless all other avenues have been exhausted. It scares me much, much more than Lyso!
Again, thank you for your reply and for the info!
My recommendation according to your post is that your dog has Atypical Cushings Disease and Lysodren is currently the preferred treatment to treat this. With 3 days of Lysodren at a low dose your dogs elevated sex hormone levels will reduce. Trilostane will not help as it causes further elevation of sex hormone levels.
Dr Carol Osborne, DVM
A related discussion, Lysodren and incontinence