Mistake on ACTH test

[Paytonsmom]

Hi I'm mom to Payton a 7 year old - 8 next month- year old Vizsla. She was diagnosed last June. Since then she has been on 60 mg of Vetoryl.

Last month she went in for a follow up ACTH test. My question is - What happens if the ACTH test is done too soon after taking the dose of Vetoryl?

When Payton was first diagnosed the vet at the clinic seemed to know a good deal about Cushing's. He provided me a summary of what to expect - in it he said there should be a 3-4 hour period between dosing and the test. However, at this follow up appointment I was called to take her home by the clinic less than 3 hours after she received her dose. She got the dose at 7:15 at home. I drove her to the vet and dropped her off. They called me to say they were done with her by 9:45. This is less than 3 hours from dosing to being ready to come home. Not what I was told by the first vet.

The next day I received a call telling me to STOP giving her the Vetoryl as she was going Addisonian. At that point I had noticed no changes in her behavior and no physical symptoms. We stopped the medicine though as directed by the vet (the previous vet had left the clinic and a different vet tested her this time). Within a few days she was just not herself so she was started on 30 mg Vetoryl. Now a month later we are noticing a slow return of the Cushings symptoms (increased water consumption and not acting like herself).

I questioned the vet at the retest and asked how the test could be finished so quickly and what happens when testing is done too close to dosing. She pretty much dismissed my concerns. (I'm not too fond of this vet since she made a serious mistake with another dog about 10 years ago). Now that Payton is having symptoms return I'm worried.

I'm taking her back to the vet tomorrow for a new ACTH test - four weeks is next week but I don't feel like we can wait that long.

[Dixie'sMom]

Welcome to you and Payton. I'm sorry she is having health issues but very glad you found us. I will let the experts on the forum guide you as they have much more experience than I do. But I will say that I think your vet owes you another ACTH free of charge because she didn't following the proper protocol for testing. The resource forum here has a lot of great information including the proper dosing/testing protocol designed by the manufacturer of Vetoryl, Dechra.

How much does Payton weigh? Can you get your hands on any of her recent blood, urine or Cushing's tests results and post the abnormal values here with the reference ranges? If you do not have copies, please request them. It will help the experts here give you more meaningful feedback.

Has the vet that diagnosed her that seemed to be very knowledgeable left the clinic? It sounds like the vet you are seeing now is being somewhat careless with your precious baby and I don't like that at all and am sure you don't. You did the right thing by questioning it and seeking out help.

Others will be around soon to welcome you and give you their thoughts. I look forward to getting to know you and your sweet girl. :D

* Here's the link to the manufacturer's recommendations in the Resource Forum. You may want to print a copy and take with you to your vet visit.

http://www.k9cushings.com/forum/showthread.php?t=185 (http://http://www.k9cushings.com/forum/showthread.php?t=185)

[labblab]

Hello and welcome to you and Payton! As Suzie has said, it will help us greatly if you can tell us more about any recent testing results, and also the symptoms and testing that initially led to the Cushing's diagnosis in the first place.

Was this recent ACTH the very first monitoring test since Payton started the Vetoryl back in June? If so, that is a huge red flag in terms of your vet, because several monitoring tests should have been performed within that period of seven months! If more tests were indeed performed, it will really help if you can get us the results for them all -- especially this last one.

Regarding the effect of the early testing...the goal of the monitoring ACTH is to determine the cortisol level at the point when the medication is having its maximal effect and the cortisol is at its lowest in the body. This information is important for both safety and dosing guidance. According to Dechra's published literature, Vetoryl typically reaches its maximal effectiveness by 1.5 hours after dosing, and returns to baseline by 12 hours after dosing.

Correspondingly, Dechra recommends testing between 4-6 hours after the morning dose with food in order to be certain to catch the maximal effect; other clinicians move the timeframe up to 2-3 hours after dosing. I have not seen anybody who recommends testing any earlier than that, so it does seem as though your vet was pressing the envelope if the testing was already finished before 3 hours had passed. However, I think the big danger of testing too early would be that you would not yet be catching the cortisol at its lowest point. So if Payton's cortisol was already deemed to be too low at the moment of testing, it only would have gone even lower had the medication not yet reached maximal level. So stopping the Vetoryl would have been the correct decision, regardless. However, the question is, what were those actual test numbers and were they really too low?

I am glad you are returning for another test, and hopefully this time around it will be completed within the proper timeframe. You will also want all subsequent tests to be performed around the same time interval so that you are comparing apples-to-apples from now on. Please let us know how things go, OK?

Marianne