Expert: Jana Connell RVT, CVT - 2/20/2010

Question
QUESTION: Thanks in advance for your answer.
My 9 year old Brittany was recently diagnosed with Cushing's. After the first 8 days of treatment with Lysodren. We went in for his ACTH test. He had been having a few problems so the vet instructed me to give him predizone for a few days before the test.
My questions is; Wouldn't the predizone affect the ACTH test? The reason I suspect this is, his cortisol was 3.9, which I was told was acceptable. The following week (after taking him off the Predizone) I almost lost him. Vomiting everything I fed him for days. I finally managed to keep the predizone in him and he made it through the night. I went to a "new" vet the next day and we changed his drug therapy. My new vet couldn't answer this question. I think it was professional courtesy, but i would like to know the truth. Since the ACTH test is to measure Cortisol and predizone is cortizol I think the vet didn't measure his own cortisol rather the predizone.

Matt

ANSWER: Matt I am not quite sure what the question is here. I have never heard of a vet giving Prednisone to a Cushings dog since the problem is too much cortisol in the bloodstream to begin with! Your dog got an overload of steroids is my guess, and that is only a guess. But Lysodren is a very touchy drug and it can cause many side effects, vomiting being the most prevalent one.

Your new vet couldn't answer the question because he doesn't know why any other vet would do what they do. No one ever knows. There are times, however, when a Cushing's dog may need some pred to get them over a rough spot, but not often.

Here is an article on Cushing's that might help you understand what it is and what the tests are. It doesn't get into the ACTH test, just that it is one of them.

http://www.peteducation.com/article_print.cfm?c=2+1597&aid=416

Here is another one that describes things more clearly:
http://www.cushings-help.com/case_study.htm

As you can see, Lysodren itself can be an issue.
So what is the new therapy that he is on now and how is he doing?
I hope this helps some. Please let me know how he does.

---------- FOLLOW-UP ----------

QUESTION: Thank you for your quick response.I'm sorry for the confusing way I asked my question, a little more info from me would have help.
The dog had been on Lysodren for 8 days. He was not eating, had diarrhea and very lethargic so the vet recommended the Prednisone for a few days till his body could produce enough cotizol to stabilize himself. Obviously, the initial therapy of Lysodren was a day or 2 longer than it needed to be. Hence, the lethargy, vomiting, etc.
When the vet did his cortizol test a few days later, I was still administering Prednisone twice a day. My concern over the test was, since the test was to establish the level of cortizol his "body" was producing and I was administering an artificial cortizol the test would indicate higher than actual. His true cortizol level, his body was producing, was very low. Hence, by administering his weekly, maintenance Lysodren
the following weekend, I sent his cortizol level dangerously lower.
Though all of this is after the fact. I'm trying to educate myself about Cushing's Disease. In my area, I don't find many vets which seem to be too knowledgeable about it. (I actually, diagnosed the disease myself and told the vet to test for it)The vet originally diagnosed old age/renal failure.
I took him off Lysodren 2 weeks ago. We start Vetoryl tomorrow. I will let you know how things turn out.
Thanks again for your help and the web links.

Matt

ANSWER: You did well Matt. And you are correct. Since Lysodren kills off the adrenal cells responsible for making cortisol, his levels did drop too low. Hence the Pred. So he is doing better now and on Vetoryl.

Cushing's is often misdiagnosed as kidney failure/hpothyroidism, etc by a vet that hasn't seen many cases of Cushing's. We saw a lot of it and it can also be a psuedo-cushing's brought on by constant bombardment of steroids for flea allergies, etc. Many other types of drugs can make the adrenals overactive to produce too much cortisol.

I am glad to see you taking things into your own hands and being proactive for your dog. Not many are willing to do that.

Thanks for letting me know and yes, please keep in touch. Your new vet sounds like he is on the ball.

---------- FOLLOW-UP ----------

QUESTION: You asked me to give you follow-up information on my dogs Cushings disease treatment.
Well... 5 week after we started trilostane he is doing great. He acts like he reversed 3 years in age. I see no adverse side effect with this drug and it is much easier to administer and regulate. His cortisol is 3.2. My only complaint is the costs. At 120mg per day it is sooooo expensive. My vet is working with a compounding pharmacy, so hopefully my next script will be a little less expensive.

Thanks again for you help,

Matt

Answer
Is this correct? "120mg per day it is sooooo expensive" Is that $1.20 a mg? or a pill?
I know drugs are expensive Matt and some Veterinary Drugs are as expensive as human ones. Many times they ARE human drugs which jacks up the cost to the vet and the owner. Believe me, vets do NOT mark up their drugs by much at all!!

I am so glad he is doing better. I hope that Vetoryl will be the new drug of choice for Cushing's dogs. There are way too many of them out there and as you found out, Lysodren is not only expensive but very hard to regulate.

Thanks again for letting me know. Tell you vet thanks for me too!