Larger dogs with Cushing's?

[Big Fish]

Hi Group Members,

Thanks for welcoming us. My dog, a 95#, 8-11 yr old, B& T coonhound, who is currently undergoing tests to R/O Cushing's. He's PU/PD (SG 1.013), have done CBC, chem panel (only irregularity mildly elevated ALT), neg. on thyroid screen, completely normal abdominal ultrasound, UA, UPCR, UCCR=78, and awaiting results for an adrenal panel (includes ACTH stim+ other hormone screen) sent to Univ. of TN. Everyone has told me Cushing's is r-e-a-l-ly hard to diagnose in dogs not to mention expensive. Seems it's more common among smaller breeds. Was wondering which tests seemed definitive for Cushing's? Does anyone have an atypical case of Cushing's? Just trying to learn more so truly appreciate the info. Thanks! Deb

[Harley PoMMom]

Hi Deb,

I have manually approved your membership so now all your posts will be seen right away. Also please just disregard the validation email that was sent to you from k9cushings.

Welcome to you and your furbaby! And yep, unfortunately Cushing's is one of the most difficult canine diseases to diagnose, which makes it one of the most misdiagnosed. One of the things that makes Cushing's so challenging is that there is not one test that can 100% accurately identify it, so vets have to perform multiple diagnostic tests to validate a Cushing's diagnosis. Are the PU/PD and mildly elevated ALT the only symptoms your furbaby has? Besides PU/PD other common symptoms from Cushing's are a ravenous appetite, skin/hair issues, pot-bellied appearance, exercise intolerance, and difficulty or unable to go up steps or jump on furniture, does your furbaby display any of these? The medications used for Cushing's do not to cure it, the sole purpose of treatment is to remedy problematic symptoms which is why strong symptoms play a huge part of the diagnosis for Cushing's.

Has an UTI been ruled out for the cause of the PU/PD? Since your furbaby has a low urine specific gravity I'm assuming her/his urine is also diluted and when the urine is diluted a regular urinalysis may not be sensitive enough to pick up any bacteria so an urine culture and sensitivity test is recommended.

The "gold standard" test for diagnosing Cushing's is the low-dose dexamethasone suppression (LDDS) test, however this test can yield false positive results in the face of non adrenal illnesses or even stress. Were the adrenal glands visualized on the ultrasound? If they were and are of normal size, with the PU/PD and mildly increased ALT being the only symptoms I'm not sure if I would have any additional tests performed for Cushing's.

We have seen cases of dogs being diagnosed with Atypical Cushing's, which is when elevations are seen in one or more of the adrenal hormones but the cortisol level is normal. Symptoms and lab abnormalities associated with Atypical are almost identical to those common in Typical cushing's. And to muddy the waters even further with Atypical Cushing's it is controversial and not really grounded in science by way of credible, sanctioned clinical trials. The reason why it's controversial is that studies have actually shown that some dogs, particularly northern breeds, can have elevated sex hormones but never have any clinical problems. I'm going to provide a very good paper entitled "Atypical Cushing's Syndrome in Dogs: Arguments For and Against". This will give you a really good idea as to why Atypical is so confounding.

http://www.2ndchance.info/cushingsbehrend2010.pdf

I am sorry for the reasons that brought you here but so glad you found us and we will help in any way we can.

Hugs, Lori

[Big Fish]

Hi Lori,

Thanks for your response! I cut & pasted your questions to try to better answer:

Are the PU/PD and mildly elevated ALT the only symptoms your furbaby has?
He's a hound and hounds are ALWAYS ravenous so hard to judge(LOL) , he is however: lethargic, exercise intolerant (used to want to walk forever now puts on the brakes after about a block) , has had some weird spots of alopecia that pop up but then go away, no stair intolerance, has had unexpected weight gain of >10# (no diet change...even slightly reduced quantity) while I can see his ribs, he's not 'pot bellied' but his underline is definitely more flat across than previously tucked up.

Has an UTI been ruled out for the cause of the PU/PD?
My vet put him on antibiotics for 2 wks to R/O a UTI. When SG was still 1.013, we did a urine culture that came back neg.

After we did the urine cortisol creatinine ratio screening test and it came back 78, my vet decided against doing the low dex test (b/c his adrenal glands were perfectly normal on ultrasound (done by a radiologist) , no enlargement, no growths). She recommended, which we just did, a full adrenal panel (ACTH Stim + sex hormone panel, sent to Univ. of TN endocrinology lab).

Thank you for the paper referral on atypical Cushing's..I'll read it. It's all so-oooo confusing to me to sort out. I'm hoping this latest test will help clarify things. We've ruled out kidney disease, thyroid, vector borne bacteria, UTI so far. He's had some contrary lab results: i.e. normal ALP & blood platelets, etc, lacks some physical symptoms....so very frustrating! Appreciate your input. Thank you, , Debbie

[Harley PoMMom]

Hi Lori,

Thanks for your response! I cut & pasted your questions to try to better answer:

Are the PU/PD and mildly elevated ALT the only symptoms your furbaby has?
He's a hound and hounds are ALWAYS ravenous so hard to judge(LOL) , he is however: lethargic, exercise intolerant (used to want to walk forever now puts on the brakes after about a block) , has had some weird spots of that pop up but then go away, no stair intolerance, has had unexpected weight gain of >10# (no diet change...even slightly reduced quantity) while I can see his ribs, he's not 'pot bellied' but his underline is definitely more flat across than previously tucked up.

Yep, those symptoms are common in dogs with Cushing's.

Has an UTI been ruled out for the cause of the PU/PD?
My vet put him on antibiotics for 2 wks to R/O a UTI. When SG was still 1.013, we did a urine culture that came back neg.

After we did the urine cortisol creatinine ratio screening test and it came back 78, my vet decided against doing the low dex test (b/c his adrenal glands were perfectly normal on ultrasound (done by a radiologist) , no enlargement, no growths). She recommended, which we just did, a full adrenal panel (ACTH Stim + sex hormone panel, sent to Univ. of TN endocrinology lab).

Sounds like your vet is on top of things which is wonderful, many GP vets are clueless when it comes to canine Cushing's.

Thank you for the paper referral on atypical Cushing's..I'll read it. It's all so-oooo confusing to me to sort out. I'm hoping this latest test will help clarify things. We've ruled out kidney disease, thyroid, vector borne bacteria, UTI so far. He's had some contrary lab results: i.e. normal ALP & blood platelets, etc, lacks some physical symptoms....so very frustrating! Appreciate your input. Thank you, , Debbie

80% to 90% of dogs have a steroid induced isoenzyme of ALP so if one of those dogs has Cushing's, you are gonna see anywhere from a mild to severe increase in ALP. Now, there is that 10%-20% of dogs with Cushing's and their ALP does not elevate that drastically, I have seen this situation a couple times on the forum, so it could be that your boy falls in that 10% - 20% group. I completely understand your frustration, Cushing's can be such a confusing disease that's hard to get one's head around.

I found this article Diagnostic Approach to PU/PD: Urine Specific Gravity on Dr. Mark Peterson's blog to be pretty interesting. Dr. Peterson is a renown veterinarian that specialize in endocrinology.

When you get those test results back from the UTK lab please do post them here...thanks! The results will also include a Treatment Option Sheet which is the treatment that UTK recommends, so please post that too. In our Resource Forum we do have articles regarding Atypical, you can found them here: "Atypical Cushing's"/Congenital adrenal hyperplasia-like syndrome/ Hyperestrinism

Hugs, Lori

[Big Fish]

Thanks Lori!

I had another rescued coonhound a while back, diagnosed with diabetes insipidus (also confounding to diagnose) and later congestive heart failure. I found the online forums on those two diseases to be SO enlightening and helpful. It's why I googled Cushing's, found this site. I'm so grateful for the links + the hands-on experiences of others.