Request For Info On Solaxine

[Batmom]

But by itself, the TSH test has far higher predictive value than TT4, which is wandering around @ 30%?! Whereas TSH in combination with other measures can get to 80-90% at least. For a good layman's discussion, see http://www.thedogs.co.uk/thyroidfunction.aspx .

[Guest grey_dreams]

Yes, that site has the same kind of information as we've been talking about. Those references also go back to "more than 10 years" with the most recent at 2005.

 

"TSH would be expected to elevated in cases of primary thyroid failure, but unfortunately, it is not a perfect test for hypothyroidism either. TSH measurement does have better diagnostic specificity than TT4, i.e., few non-thyroidal conditions cause a high TSH value. However, disappointingly, not all hypothyroid dogs have the expected high TSH. The proportion that do not has been variably reported but compared to gold-standard TSH response testing the figure probably lies between 15 and 20% (Dixon and Mooney 1999)."

 

15-20% error rate.

 

The use of T4/TSH ratios still depends on error rates in both measurements.

 

The conclusions from that link:

"Much of the above would give the impression that hypothyroidism does not occur in the Greyhound. Of course this is incorrect and well documented cases of Greyhound hypothyroidism do exist but several pieces of evidence suggest that it is relatively uncommon compared to the prevalence in other breeds."

"Future work should focus on correlating other measures of thyroid function (e.g. T3 and TSH) with perceived clinical syndromes of hypothyroidism in the Greyhound in order to generate some diagnostic performance data (diagnostic sensitivity and specificity) and clarify which clinical presentations are associated with hypothyroidism and those that are clearly not."

[Batmom]

Well, yes, he's doing a metastudy. I thought this was one of the worthwhile bits:

 

"It makes sense that the combination of TT4 and TSH has the potential to benefit from the advantages of each (good sensitivity of TT4 and good specificity of TSH). Indeed, at prevalence levels of 10%, the positive predictive value (PPV) of T4/TSH ratio exceeds 80% when TT4 alone would have a PPV of less than 30%. That means that if a positive result is obtained from a T4/TSH ratio, the clinician could be more than 80% confident that the patient was truly hypothyroid. In contrast, faced with a positive (subnormal) TT4 result alone less than 30% of such cases will actually have the disease. At the same time negative predictive value (NPV) of the T4/TSH ratio is excellent at around 99% meaning that almost complete confidence can be had that a dog with a normal T4/TSH ratio does not have hypothyroidism."

Thus it makes sense to me to use the TSH. Elsewhere in his article he points out the problem with T4 -- namely, that even fT4ed, which is the most realiable measure and used only by a few labs such as MSU, is not measurable at levels that are relevant for sighthounds.

If even half the percentages of medicated dogs on GT are accurate, we would have to conclude that greyhounds have a higher level of hypothyroidism than golden retrievers and dobermans. Which is highly unlikely to be the case.

Edited March 4, 2010 by Batmom

[Guest grey_dreams]

Positive predictive values and negative predictive values depend on the error rate of the tests and misdiagnosis, ruling out false positives/negatives. The TSH test has a 15-25% error rate. So the freeT4 divided by TSH will still be subject to high error.

 

Edited to add: Free T4 is routinely measured in the full thryoid panel, not just at MSU. They measured it here too.

Edited March 4, 2010 by grey_dreams

[Batmom]

You're saying that the fT4 in combo with TSH has a *higher* error than each alone? I disagree strongly.

 

Guess we'll just have to leave it that some folks feel lots of greyhounds really are hypothyroid. My personal feeling is that almost none are, and I believe most of the extant research backs up my assertion. For an individual dog, I would not test anywhere besides Michigan State as they incorporate into their interpretations the results of published, peer-reviewed research. That is not true of anyone else offering this type of testing/interpretation in the U.S.

[Guest grey_dreams]

You're saying that the fT4 in combo with TSH has a *higher* error than each alone? I disagree strongly.

 

Where did I say the error was higher?

 

The site you posted also says that some greyhounds are hypothyroid - see the quote that I posted above.

 

For an individual dog, I would not test anywhere besides Michigan State ...

Yes, I understood that.

 

...as they incorporate into their interpretations the results of published, peer-reviewed research. That is not true of anyone else offering this type of testing/interpretation in the U.S.

 

That's not true. These are the references sent to me by Jean Dodds at Hemopet. All of these are published through the peer-review process and appear in high-ranking vet journals.

 

● Dixon RM, Graham PA, Mooney CT. Serum thyrotropin concentrations: a new diagnostic test for canine hypothyroidism. Vet Rec 138: 594-595, 1996.

● Iverson L, Jensen AL, Høier R, et al. Biological variation of canine serum thyrotropin (TSH) concentration. Vet Clin Pathol 28:16-19, 1999.

● Jensen AL, Iversen L, Høier R, et al. Evaluation of an immunoradiometric assay for thyrotropin in serum and plasma samples of dogs with primary hypothyroidism. J Comp Pathol 114: 339-346, 1996.

● Diaz Espineira MM, J.A. Mol JA, Peeters ME, Pollak YWEA, Iversen L,van Dijk JE, Rijnberk A, Kooistra HS. Assessment of thyroid function in dogs with low plasma thyroxine concentration. J Vet Intern Med 21:25–32, 2007.

[Batmom]

I didn't mean that MSU sends you references. I meant that they use *current* knowledge, as well as current tests such as fT4ed, in their analysis.

 

 

In any case, OP has a different issue.

[Guest grey_dreams]

I didn't mean that MSU sends you references. I meant that they use *current* knowledge, as well as current tests such as fT4ed, in their analysis.

Right. So does Hemopet. She sent me those references to document to me the data on which their work is based, because I asked so many questions. MSU is not the only lab in the world that uses current knowledge.

 

And like I said above, all full thyroid panels measure free T4. They did here too.

 

In any case, OP has a different issue.

Yes she does. I posted directly in response to the OP in my first post in this thread (see post #17) before the thread got hijacked for another discussion about testing methods.

 

Edited to add: Hey Batmom, it's late here and I'm off to sleep. I'll catch up with your next hits tomorrow. Enjoy the lull.

Edited March 5, 2010 by grey_dreams

[Batmom]

fT4ed is different from fT4. Hemopet doesn't use fT4ed and doesn't test TSH. I think those things are important for sighthounds.

[LuvAPuppy]

Did he come with medical records (guessing no or you wouldn't be asking us stuff?) Did his deceased owner have family that the group might contact and see if they have any idea where he was vetted? It would be nice to have not just his last thyroid labs but anything of his past.... Labs can be re-drawn if his records aren't accessible, that not an issue except paying for it!

 

 

Oh yeah, I have records. I'm holding in my hand 20 pages of vet records, and that's just for the last year. It's not that he's an unhealthy dog; he actually looks pretty good. I think it's just a combination of a daddy who loved his boy very much & took him to the vet for any and everything and a vet that documents EVERYTHING, including who your receptionist was for the visit. Apparently, there was 80 pages total for the years Larry was with his previous owner.

 

It looks like he's had full bloodwork done at least twice in the last year, but I don't know what a lot of these numbers mean. I think I will email Dr. Dodds and see if she can help me decipher some of this.

 

I have other questions concerning his health, but I'll wait and start a different topic for that.

 

Adrianne, Carl's weight ranges from 72 - 75 on average and he gets .7mg of Soloxine total per day.

 

 

In looking at Larry's records, it looks like his weight stays between 77 - 79 pounds. I also see that he was actually started out on .8 mg of Solaxine 1 pill 2x daily for a total of 1.6 mg daily.

LOL, I'm glad you have many many records! Better too much over too little!

 

I *may* be able to help you with the lab results as I was a tech in a vet lab for many years as well as being a human health care person, BUT different labs use different machines and reagents and will have different normals. And, since greys levels can be different still, you'll probably be more comfortable showing those to the vet. The offer stands though

[seeh2o]

Pardon my hijack, but the thing is, if I went by the "typical rule of thumb" Carl would be blind by now. The only "typical" symptom he had was bald thighs, chest and neck. His atypical symptom, corneal rings, was misdiagnosed several times by two different vets, even my current vet didn't know what she was looking at and sent me to a specialist. I pressed and told my vet I wanted a thyroid panel, she wasn't opposed to it, so she ran it. I shudder to think how bad off he would be now if we hadn't run it based on a gut feeling. The bottom line is, if you can afford to have the test run, do it, better to lose some money and find out your dog isn't hypothyroid rather than to have your dog develop serious irreversible problems. Ok, hijack over.

[Guest MZH]

There's no point to doing a full thyroid panel unless the dog has been off medication for @ 6 weeks. While the dog is taking medication, it doesn't show you anything useful.

 

You don't have to taper off thyroid meds. See last question here: http://www.animalhea.../Monitoring.php

 

And for more about thyroid testing, etc., see here: http://www.animalhea...roid_Canine.php

 

Thanks for the links to two excellent papers from the experts at MSU!

[CaliforniaGreys]

Pardon my hijack, but the thing is, if I went by the "typical rule of thumb" Carl would be blind by now. The only "typical" symptom he had was bald thighs, chest and neck. His atypical symptom, corneal rings, was misdiagnosed several times by two different vets, even my current vet didn't know what she was looking at and sent me to a specialist. I pressed and told my vet I wanted a thyroid panel, she wasn't opposed to it, so she ran it. I shudder to think how bad off he would be now if we hadn't run it based on a gut feeling. The bottom line is, if you can afford to have the test run, do it, better to lose some money and find out your dog isn't hypothyroid rather than to have your dog develop serious irreversible problems. Ok, hijack over.

 

I remember this with Carl Connie, and your own research paid off big time.

Misty's thyroid situation wasn't common either, only symptom she showed was losing nails.

[Guest Adrianne]

Thank you everybody for the wonderful information and the links. I'm going to read everything today to get educated on this and email Dr. Dodds.

 

I know I seem completely dumb on greyhound health, but Wilbur was the healthiest dog ever up until he broke his leg. In eight years, he had zero health issues and had the body and health of an eight or nine year old. Only twice did he go to the vet for non-routine issues, and those were both injuries. I wish I had known more with him, because I had to rely too much on my vet's advice. Granted, we're supposed to rely on our vets, but I believe two very bad decisions were made for him that, if nothing else, reduced the quality of his life. Decisions I went along with 100% because I didn't know any better. I'm not saying the vet was incompetent, but in the early days there were other options that I could have pushed for had I been educated.

 

 

And honestly, if I had to make a major decision today concerning Larry and his thyroid condition, I would again be completely at the mercy of my vet's opinion. So.....I don't want to be in that uneducated position again. Just as Wilbur did, Larry is depending on me to make the best decisions for him.

 

I think I'm also going to call the vet who was treating Larry. I don't know if they'll be able to give me any information without the release of his previous owner's family, but I can only try.

 

Thank you again. This is the best place for information and directions to other information. I think joining GreyTalk should be a requirement for all new greyhound adopters.

[LuvAPuppy]

Pardon my hijack, but the thing is, if I went by the "typical rule of thumb" Carl would be blind by now. The only "typical" symptom he had was bald thighs, chest and neck. His atypical symptom, corneal rings, was misdiagnosed several times by two different vets, even my current vet didn't know what she was looking at and sent me to a specialist. I pressed and told my vet I wanted a thyroid panel, she wasn't opposed to it, so she ran it. I shudder to think how bad off he would be now if we hadn't run it based on a gut feeling. The bottom line is, if you can afford to have the test run, do it, better to lose some money and find out your dog isn't hypothyroid rather than to have your dog develop serious irreversible problems. Ok, hijack over.

 

My Great Dane was diagnosed on routine screening. she had not one single symptom EXCEPT...skin infections. she'd get pus filled cysts in the summer that we and the vet attributed to her love of lying in the lawn basking...bug bites. The yearly labs had T4 & TSH included and they came back off. Vet said she didn't believe it and apologized to me since I worked for the lab that ran the test. We sent to Michigan for the full panel and she was indeed hypothyroid. No hair loss, no weight gain. No serious lethargy, no more than usual for a Dane

[ShantisMom]

Dr. Dodds is very helpful. Shanti is having thryoid issues. She has been on .5 2x day and fine for years. Now her thyroid is not registering. We increased her dose to .75 2x a day. Still not registering. My vet contacted Dr. Dodds who just came back from a conference on it.

 

In my girls case, we are holding for a while longer at this dose and running another full panel including sensitivity tests. She acts fine now. We suspect her Valley Fever medication is throwing off the results or the way she is metabolizing her soloxine. I know it is a problem if the dose is too high too. She considered Shanti's dose at the high end and did not want to increase it. Shanti is also one of those dogs that did not do well on the generic. She got mean!

[Guest grey_dreams]

Thank you everybody for the wonderful information and the links. I'm going to read everything today to get educated on this and email Dr. Dodds.

 

That's wonderful Adrianne! That's exactly the best thing you can do: educate yourself as much as possible, and then consult with several experts including your own vets and Dr. Jean Dodds. She is wonderful and will readily help you with lab interpretations and advice for what to do. When I was going through this with Zuki, what really gave me confidence with the treatment and dosage plan was the fact that my own 2 vets + the top vet endocrine specialist in Netherlands + Jean Dodds all came to the same conclusions. Jean and the specialists here had no conversations with each other, so they came to the same conclusions independently. My own research also supported their conclusions. So then I felt very confident to implement their plan. Zuki is now very healthy and happy. He also had 1 atypical symptom that has completely resolved now.

 

Edited to add: Zuki had 1 atypical + 3 typical symptoms, and all 4 symptoms have now resolved. In the results from the intitial full thyroid panel tests, he had a "normal" TSH value while the other values were low; so he was one of the 25% population of dogs who ARE hypothyroid but come back with an incorrect measurement of TSH due to the fact that the antibody used for the tests does not recognize canineTSH with 100% accuracy. He's doing great now with treatment!

 

Good luck to you and Larry, and have fun researching!

Edited March 6, 2010 by grey_dreams

[Guest Adrianne]

It looks like a thyroid panel was done on Larry on April 3, 2009. I've emailed Dr. Dodds and am waiting to hear back from her.

[Batmom]

Good that a panel was done!

[CaliforniaGreys]

It looks like a thyroid panel was done on Larry on April 3, 2009. I've emailed Dr. Dodds and am waiting to hear back from her.

 

Please keep us posted. Jean usually gets back to people very quickly, even if she's out of the country.

I swear the woman never sleeps

 

Did you use the hotmail address?

[Guest Adrianne]

It looks like a thyroid panel was done on Larry on April 3, 2009. I've emailed Dr. Dodds and am waiting to hear back from her.

 

 

Did you use the hotmail address?

 

 

I did. Thank you so much.

[Guest Greytluv]

Jean is the best

[PatricksMom]

Shanti is also one of those dogs that did not do well on the generic. She got mean!

 

It was probably because the generics don't necessarily have consistent levels, and sometimes vets offices (or pharmacies) switch generics without telling you. When this happened to Patrick he throws up, and goes back to biting (only me for some reason.) So it's only soloxine for him.

 

Patrick came to us with no symptoms but low thyroid (well, a bald butt straight off the track). We didn't medicate until he suddenly started biting me for no reason--treating the thyroid fixed that, but if his levels get off he goes right back to doing it.

[sweetdogs]

When my 2 vets + the top endocrine specialist in Netherlands + Jean Dodds all agreed about the 6 week trial for Zuki, they told me that if he didn't respond to the med, he would have to be taken off very slowly over the course of a few weeks, by gradually decreasing the dosage.

Just heard Dr. Couto say today that thyroid meds should be tapered off slowly over 4-6 weeks.

[CaliforniaGreys]

When my 2 vets + the top endocrine specialist in Netherlands + Jean Dodds all agreed about the 6 week trial for Zuki, they told me that if he didn't respond to the med, he would have to be taken off very slowly over the course of a few weeks, by gradually decreasing the dosage.

Just heard Dr. Couto say today that thyroid meds should be tapered off slowly over 4-6 weeks.

 

This is how I've been told to do it as well, and I can still remember Patti, Flashman's mom telling me this is what Dr C said as well

Edited March 7, 2010 by cbudshome