Westie - 12yrs old male - Cushing's

[PWestie]

Hi,

I'm new to the forum, and have a Westie that's recently been diagnosed with Cushing's. He's 12 years old, weighs 19 lbs, doesn't have other health issues. He had an ultrasound in Oct, 2015 which showed slightly enlarged adrenal glands and a slightly enlarged liver but no masses or other issues. They suspected Cushing's at the time, but we decided to wait to treat him until his symptoms became more prominent. They have, so on 3/23/2016, he had a Dexamethasone Suppression Test with the following results:

Pre Dexamethasone = 5.3 ug/dL
Post 4 Hr Dex = 4.1 ug/dL
Post 8 Hr Dex = 7.1 ug/dL

Cushing's was confirmed. We began to treat him with Vetoryl (10mg/day). After he was on the drug for 7-10 days we did a ACTH test: Pre=.3 ug/dL, and Post = 9.5 ug/dL. The vet wanted to keep him on the med a bit longer as guidelines say that within 9 ug/dL on Vetoryl can be fine and he was at 9.5 ug/dL.

Ten days later we did another ACTH Test. Pre=1.2 ug/dL, Post=9.3 ug/dL so we increased his Vetoryl dosage from 10 mg/day to 10mg/am & 5 mg/pm per day.

We retested ACTH 10 days later with the following results: Pre=2.9 ug/dL, Post=10.2 ug/dL.

The little guy doesn't seem to be responding to the Vetoryl, so the vet recommended changing the med from Vetoryl to Lysodren. He's only at a very moderate dose of Vetoryl for his weight (i.e., we could increase it), but the little guy hasn't responded at all to that med so the vet recommended we move to Lysodren.

Any comments or suggestions would be welcomed!

Thanks!

[Renee]

I would not be so quick to jump ship on vetoryl. The best, and safest, method of controlling cushings is to go low and slow. Cushings doesn't develop overnight, nor should we expect symptoms to resolve so quickly either.

Since it does not appear you did an ACTH before starting treatment, there is no way to judge how far your westie's cortisol has dropped. It may be that it has dropped significantly over the last month, and you just don't know. If the starting cortisol has been, for example, 40 ug/dl, then you would have had a massive decrease in just a month. No way to know.

I am concerned your vet would be so quick to say it's not working. Are you seeing any symptom resolution? Does your vet treat other cushings patients successfully?

My suggestion would be another small increase, such as 10mg am / 10mg pm, and retest his numbers in 2-3 weeks.

[Tinkerbellsmom]

Hi PWestie, I'm new here too and trying to figure this all out but wanted to welcome you!

[molly muffin]

Hello and welcome to the forum.

I agree with Renee I would go to 10mg/10mg and see how he does on that before switching. That would put you right at the recommended starting dose of 1mg/1lb

[labblab]

I agree that I don't believe I'd abandon the Vetoryl quite so quickly, but I do understand why your vet is puzzled by the cortisol increase after the Vetoryl dose was also increased. Obviously, that is indeed unexpected. Here's a couple of quick questions...

Were all three monitoring ACTH tests conducted within the same timeframe (Vetoryl's manufacturer recommends 4-6 hours after dosing)?

On all testing days, was the Vetoryl given along with breakfast? Vetoryl is not metabolized efficiently when given on an empty stomach, so ACTH test results will likely be higher on days the medication is not given with food.

I'm just searching for reasonable explanations for the results you got...

Marianne

[PWestie]

Hi,

First of all thanks to everyone for welcoming me to forum!

In response to the question about his ACTH tests, we'd feed him around 6 am and give him his meds with the food, and then he'd have the test within the 4-6 hour window after taking the med, so we should be good in that way. Here are his ACTH results.

Cortisol-Pre Level Cortisol-Post Level
3/31/2016 .3 ug/dL 9.5 ug/dL
4/12/2016 1.2 ug/dL 9.3 ug/dL
(4/14/2016 - increase from 10mg to 15mg)
4/26/2016 2.9 ug/dL 10.2 ug/dL
(4/28/2016 - increase from 15 mg to 25 mg)
Going to schedule another


In talking to my vet last week, we decided to increase his dosage of Vetoryl to 25 mg/day (15mg am and 10 mg pm). I've been tracking his water intake since mid-April and when we increased his dosage from 15mg/day to 25mg/day his water intake dropped after being at that level of Vetoryl for one day and then it started to climb again up to 30-40 oz/day. (We also saw this decrease for a day when we went from 10 to 15 mg and it also went back to the higher level.) He's also urinating as much as ever given, "What goes in must come out."

To me, it doesn't seem as though the Vetoryl is having any lasting impact on his symptoms and I'm kind of at a loss. I just want the little guy to feel better.

I need to chat with my vet today to schedule another ACTH test ... but I'm also feeling like the Vetoryl isn't making any real change for him. Do you think we should (1) increase the Vetoryl again if after an another ACTH we have similar pre & post levels or (2) stop the Vetoryl for 5 days and try Lysodren ... and if so at what level?

Could we be missing something else that would make him less responsive to the Vetoryl?

Thanks for all the help ... seems like Cushing's conditions can be so uniquely individual that it's hard to figure out how to treat each one so all your assistance is much appreciated!

[lulusmom]

Hi and a belated welcome to you and your Westie boy.

I wanted to chime in and say that I too believe you may be premature in throwing in the towel on Vetoryl (trilostane) The recommended starting dose of Vetoryl is 1 mg per pound of weight and your vet started your 19 lb boy on half that dose. At 15 mg you were at about 3/4 of that dose and the current dose of 25 mg is only 1.3 mg per pound. It is therefore not that surprising you have seen little evidence of control yet. To give you a frame of reference, my 4.5 pound Pomeranian stabilized on 30 mg once a day and my 7 lb Pom stabilized on 15 mg twice a day. That equates to daily doses of 6.67 mg/lb and 4.3 mg/lb respectively. I truly think the dosing prescribed by your vet has been cautiously low, which is not a bad thing, and I think you have a ways to go before anybody should consider your pup as being hopelessly resistant to the effects of Vetoryl. It is not uncommon at all for dogs to require multiple increases in the first month or two of treatment so my vote is to give Vetoryl more of a chance to work it's magic. Do some dogs not respond to Trilostane? Absolutely, but it is rare.

Glynda

[PWestie]

Thanks for all your comments. The little guy has another ACTH test this morning so we'll see how his numbers come out.

I had read on several different sites that the recommended dosage for Vetoryl was 1-3 mg/lb depending on how the dog responds and the recommended starting dosage for his weight could have been 30 mg. My vet started him out at conservative level, which I appreciate, and maintained it at that level because we were away on vacation and wouldn't be around to monitor changes with him. But, it leaves us quite a bit of room for further dosage increases (he's 19.2 lbs so could go as high as 57 mg under that guideline) and given others experiences with their dogs, which have taken up to 4 or 6 times the recommended dosage/lb of body weight, it would seem we should keep building the dosage. It's just sometimes hard to be patient. :-)

[Renee]

Yes, you may end up building his dosage up.

Your vet was correct to start out conservatively, although 10mg may have been extra conservative, but nothing wrong with that. Better safe than sorry!

My pug, 20 pounds, started at 20mg and eventually worked her way up to a total of 40mg to stabilize over a period of about 5 months. She's completely off her medication now, but that's a whole other story. It may just be that your little guy needs a higher dose of the medication and working your way slowly is the best way to do it!

[hermine]

hi. I'm new to Cushings. My Boston terrier, Maggie was diagnosed in February and we have been working inadjusting her meds. She weighs 30 lbs. but is at 90 mg, 1x per day now for about a month. She's drinking less, going out more, more alert, but unable to lose weight. I would say to keep working on the dosage a while longer. good luck!

[molly muffin]

None of us ever know where a dog with end up stabilizing at on medication.
We started out at 8mg for my 18 lb dog (at that time) and are now at 21mg and my dog now weighs in the 16lb range.