Suspecting Hyper-T

Hi all,

Weeble has had hyper-t symptoms since April. Because of the normal T4s, it was attributed to the loss of her housemate, aging, then diabetes. After doing a closer reading of the bloodwork and research, I've becoming extremely suspicious that she's what they call a "grey area" case--where kidney disease is masking the real numbers and is particularly prevalent in older kitties.

Her symptoms are generally neediness, nervousness, vocalization, increased thirst (this was the case in April when she was barely renal, but they confirmed it with USG, which I now know can also be low with hyper-t), less sunbathing and more cooling on the floor. More recently she seems to have an increased appetite.

Her current T4 is 2.6 (normal range .8 to 4)
BUN 35 (normal range 14-36)
Creatinine 2.6 (normal range .6 to 2.4)

Also, I read a mention of a study done in which Hyper-T causes magnesium loss--and low and behold she's low, only by .1, but still low.

Not too bad, really, but the symptoms remain. And better safe then sorry. On the bloodwork they suggest a Free T4. Is there any other test I should be asking for? Any other input or suggestions?

 

Get the freeT4 (fT4). Let's either get the hypert dx or rule it out completely. Once you get the test done, let us know, if it's not hypert, maybe we can brainstorm.

Regarding kidney disease and masking numbers, I belive the hypert masks kidney disease. The increased metabolism keeps the kidneys busy and the numbers lower. Some cats when they become regulated or get the I131 you find they have kidney disease.

 

Thanks, Jennifer.

I think it's both, unfortunately. Reading this from the Holisticat website is what is turning the nagging voice in my head to some sort of action:

So many different ways to lose!

 

Does the lab report give a grey-zone range? I am looking at an Idexx report and it says:
normal 0.5 - 4.7 ug/dL
Also says under comments:

Interpretive ranges:
<0.5 subnormal
0.5-4.7 normal
2.3-4.7 grey zone in old or symptomatic cats
>4.7 consistent with hyperthyroidism

Cats with subnormal T4 values are almost exclusively euthyroid sick or
overtreated for their hyperthyroidism. Older cats with consistent
clinical signs and T4 values in the grey zone may have early
hyperthyroidism or a concurrent non-thyroidal illness. Hyperthyroidism
may be confirmed in these cats by adding on a free T4 or by performing
a T3 suppression test. Following treatment with methimazole, T4 values
will generally fall within the lower end of the reference range
(0.5 - 2.3).

 

The bloodwork is done by Antech. They don't give ranges, but it when it's 2.5 or over and, I'm assuming, taken together with the her age, the paperwork automatically suggests to request a Free T4. Over the past 9 months, she's been 2.5, 2.4, and now 2.6.

 

Hi, does Weebles like his wet food soupy? I see that he's a tough one to get off dry, but the more wet you can feed, the better. If he'll eat soupy wet food, all the better. You might try sprinkling some Fortiflora on the wet food as enticement. Another thing that works real well for my herd is sprinkling freezedried chicken (or salmon) on the wet food. There is a good sized bag of 100% freezedried chicken in Petsmart in the dog section, which is a big hit and also much cheaper than LIv-A-Littles chicken.

Another way to get your cat to drink extra is to simmer some chicken in water. The broth will quickly get scarfed up. The chicken is good for the cat too, of course.

Did your vet check Weebles' heart? They can develop a murmur or have an elevated heart rate from hyper-t.

good luck,
laur

 

I've actually finally had success moving her to canned food. Last night was (hopefully) the last night. It only took seven short months!

And I am very concerned about the heart thing--particularly because she gets cisapride which I know can affect heart rate as well. Vets have listened to her heart, but no one's heard anything, but having had animals with murmurs that appeared suddenly (and not ending well), I know they can be tricky to hear and/or crop up suddenly.

The hemming and hawing is also related to vet issues--I really think I need to try yet another one again, but my options are limited because she doesn't travel well (understatement) and I have to stick within a 3 mile range. I have a home vet I like, but she doesn't really have the diagnostic tools. I know this only needs bloodwork, but I would have to start over if she needed x-rays or something.

I really hope I'm wrong. I so don't want to add to her ailment list. Which most recently includes crystals in the urine--even after eating more wet than ever before.

 

oops, I said "he" for Weebles! I was thinking so hard about my hyper-t foster boy (Venture) that I guess I transferred that onto your cat. Sorry!

Congrats on sticking to your guns on the wet food. High five! You did great. Whatever problems Weeble is having, they'd pretty much all be worse on dry food. I don't know much about crystals, but the wet has to be helping her throughput.

I have a neuro-injury cat on cisapride too. For him the heart risk was pretty negligible. But for Weebles' multiple conditions, that definitely merits close attention and some questions.

You might ask the vet about using some acepromazine, even if only a very low dose of 1/8 or 1/4 tablet. It may take the edge of Weeble's panic, and if you can do that a few times, it seems to help because they can learn that there isn't anything awful going to happen.

Also, conversely, just going to the vet more often makes it easier on the cat. Suffice it to say that I've no doubt funded the remodeling at the vet ER/hospital between my various cats. Danny and Min especially were poor travelers (Min would get so scared he would literally need oxygen), but thank goodness, over time, all three showed really great improvements in their ability to handle vet visits. Because there really was no choice, it was live-or-die frequent vet visits. Just before he died suddenly in June, Min had gotten to the point where he would poke his head out from under his towel, and look at the vet while she praised him. And his last time there, he came out from under his towel and even wanted to walk around the room!

So (ace or not) maybe if you took some more trips to the vet, just go in the treatment room and then walk out basically, that would help ease Weeble's fears.

good luck,
laur

 

If you have any T4 data from the last few years it would be interesting to compare it to the most recent data.

My internal med specialist was the first to suspect Tilly had hyperT in early-mid 2009 based on (1) the fact that her T4 wasn't declining with age as one would expect and (2) some weight loss. Tilly was also quite active, boardline hyperactive.

I was skeptical and every other vet I talked to said "no hyperT". But the specialist was right on the money. Histopathology after a partial thyroidectomy in Jan 2010 and of course the scintigram in Sep 2010 confirmed the diagnosis.

If you are interested, here are the test results: http://www.tillydiabetes.net/labs/Tilly ... ummary.pdf Interestingly, Tilly's free T4 was still in the normal range at the time the specialist already suspected hyperT.

Add to all that, we went in for radioiodine treatment 1 month ago. Now her T4 is down to 1.3 and creatinine 2.1 (<2).

The gold standard test for diagnosis of hyperT is a scintigram (scintigraphy). The cat only requires a short sedation with propofol to do this test. I personally wish I had done this test a lot earlier. And of course had her treated with radioiodine.

 

I'm leaving for the vet in a few minutes to get the fT4 so unfortunately I won't be able to see your reply before I go.

My concern about that test and the conventional treatment is her kidneys (due to all the info referenced above and her age; even a year ago this would have me less concerned), but I see that Tilly had high kidney numbers as well.

These are the moments I really wish I had a vet that was more on the same page as I am--it's all so confusing and I'm not completely comfortable making all these complex decisions myself. Can you tell me a bit more about your understanding between the relationship between the hyper-t and the kidney disease? Your experience seems to contradict the idea that reducing thyroid activity can lead to a worsening of the kidneys (due to loss of blood circulation as I understand it in my pea brain)...

 

If you become more certain your cat has hyperT, you could try the oral or transdermal methimazole first (low dose) and see how things progress. Make sure you are vigilant with the bloodwork, since a significant proportion of cats experience side-effects. If your cat does well on the oral meds, you might just be able to leave it at that.

Going ahead with the radio-iodine treatment was a difficult decision for me to make, given Tilly very likely having CKD and not knowing how much worse it could potentially get. This is apparently not easy, if not impossible, to predict. The vets at the center where Tilly had her radio-iodine treatment done, said her CKD would very probably be mild but that it also might not be.

However, she didn't tolerate the oral med (hepatotoxicity) which kind of limited our options.

Based on the data in the PDF file, I got lots of feedback from people on the hyperT forum and others that have had cats with early stage CKD treated with radio-iodine. Not all centers are willing to treat such cats, but some centers are. The cats' CKD stayed stable after treatment, which I found very interesting and motivating. Plus my vet also wanted the hyperT eliminated ASAP and for us then to "deal with" the probable renal disease.

I also found this paper to be very helpful in helping me make my decision: http://www.fecava.org/files/ejcap/882.pdf

 

Cotton had Hyper-t for over a year and we were watching his kidneys from the moment it was diagnosed. He responded well to the oral medication, though and there was not rise in his kidney numbers, so we were lucky.

It's not uncommon for cats to have both kidney disease and hyper-t, but the hyper-t masks the kidney disease because it keeps thier systems running, essentially in high gear. So the treatment, and slowing the thyroid down often causes the kideny disease to become noticeable. I do have severla friends with hyper-t and kidney disease kitties who use the oral medicine to keep the two in balence. Essentially they figure out a dose that slows down the thyroid enough to minimize damage, but keeps it running quickly enough to keep the struggling kidneys working well.

 

Hey Jennifer,

I wish that we could say that the fT4 is the 'end all be all' test to "rule it in or out completely" but this test is fraught with inaccuracies so we have to think of it as just one more tool in our tool chest and not a definitive test, by any means.

Some lab diagnosticians have recently gone so far to call the fT4 essentially worthless but I would not go that far.

Also, it must be stipulated that the fT4 be done via ED because, to the best of my knowledge (from my VIN reading), that testing protocol has the most validation data behind it.

The fT4 can be falsely elevated for many reasons. Concurrent illness in the cat....the sample being mishandled (over-heating...a delay in testing...)

I have started to look at the fT4 ED with a bit of a jaded eye.

Scintigraphy is the best tool to Dx HT at this time but is expensive and not always readily available. In my area, they only sedate ~1% of their patients....no anesthesia needed for this particular clinic that is run by Dr. Michael Broome....one of the...if not *the* pioneers in I-131 treatment. I am lucky that he is only 45 minutes from me as I am facing these issues with one of my own cats.

 

PS...for me, I-131 is the only answer since I really hate tapazole due to its toxicity issues, hassle, cost, need for more monitoring, etc.

 

Must be the same diagnostician our Dr S talks to. He just told me yesterday that some Antech lab person told him it's worthless :razz: (We ordered it anyway).

Dr S too, I think. He said it's of value to him only if the T4 is borderline.

Kirsten, I saw your update on the Calcitriol group. Glad Tilly's feeling so much better already :smile: