Thoughts?

[Lepper]

After many tests, my 85 lb black lab was diagnosed with Cushing's. He is almost 13 years old. Pituitary, because his ultra sound was negative on the adrenal glands.
He was put on 100 mg of Triolstane, 50mg every 12 hours. After a couple days, his water intake slowed down but he stopped eating.
He was recently diagnosed with spinal stenosis so his back legs were kinda weak already (not too too weak) but he could hardly get up after day 4 or so days of 100 mg.
Dr. said to stop meds so we did. We gave him a week break because some of us were going out of town and we all wanted to keep an eye on him.
He has now started on half the dose, 25 mg every 12 hours. Prior to meds, it's been extremely hard in that we needed to let him out every few hours, including the night time.
None of us have slept a full night in months. It seems he is also just barking at weird times and it was something he never did unless he needed something. It's not his I want to go out bark, it's like a restless bark or something is bothering me bark. He's usually fine during the day and doesn't do that during the day.
It's like having a newborn and they get fussy in the evenings. Has anyone experienced this? My vet said try trazadone but that never really lasts and I don't want to keep him drugged up at night. Any suggestions or thoughts?

[labblab]

Hello, and welcome to you and your boy! As you can tell, I’m a Lab lover, too ;-). First of all, kudos to you for taking such good care of your boy that he’s made it to nearly 13. That’s wonderful! Sadly, neither of my first two beloved Labs (one of whom was my Cushpup) made it even as far as 12. My sweet Lab girl now has just celebrated her 11th birthday, and we have high hopes that she still has more quality time left. I know you’re surely hoping the same for your boy, as well, and we’ll do our very best to help you along the way.

Given his age, though, !’m guessing that it can be tough at times to isolate which symptoms may be caused by Cushing’s vs. which symptoms are related to his senior status. For instance, things like hind end weakness can be especially tough to diagnose. Is it due to the muscle wasting of Cushing’s, or instead arthritic pain or other orthopedic issues? Having said that, it sounds as though it is his excessive urination that led to the Cushing’s testing. Can you tell us more about the testing process, and whether he has any other outward symptoms or lab abnormalities that are consistent with Cushing’s? The reason why I ask is because both of the diagnostic Cushing’s blood tests can be vulnerable to “false positives” when a dog is suffering from illnesses other than Cushing’s. Although excessive urination is a classic Cushing’s symptom, other disorders can cause it as well. For that reason, we feel more secure about a Cushing’s diagnosis if we see a number of consistent symptoms as opposed to just one or two. Excessive appetite, pot belly, seeking cool places to lie down, hair loss, and muscle weakness are some of the other classic symptoms. Does your boy have any of these problems, as well?

Since you’ve already started treatment, however, let me jump ahead. Unless your boy has regained his appetite and ability to get up as he did before, I’m concerned about restarting his trilostane at any dose. As it turns out, 100 mg. is a higher starting dose than is currently recommended by most clinicians. Dechra, the manufacturer of brand name Vetoryl, recommends a starting formula no greater than 1 mg. per pound. However, other researchers and clinicians are suggesting that larger dogs should be started off on even smaller doses.

Dechra recommends starting treatment at 1 mg/lb (2.2 mg/kg). A UC Davis study suggests that dogs weighing >66 lbs (30 kg) tend to be more sensitive to Vetoryl and require less of the drug to control the clinical signs of cushing’s than dogs weighing less <66 lbs (30 kg) Based on that study, UC Davis’ established protocol for treating larger dogs starting at doses ranging from .3 to .5 mg/lb (.66 to 1.1mg/kg)

Based on these newer recommendations, your new daily dosing total of 50 mg. seems more reasonable. However, until or unless you feel confident that your boy has completely recovered from any oversuppressive effects of the earlier overdosing, I don’t think it’s safe to start giving him any trilostane at all. So how about his appetite — is he eating normally again? That really is a key consideration, because trilostane is not metabolized properly unless it’s given along with a meal, it can cause GI upset given on an empty stomach, plus most importantly, lack of appetite can signal a cortisol level that remains too low.

I’ll go ahead and close for now, even though I do have more thoughts to add. But I’m afraid I’ve already bombarded you with enough questions for the moment! So I’ll give you a chance to reply, and then we can talk some more. Most importantly, once again — welcome!

Marianne