T3 Suppression Test for My Cat Max

[caption id="attachment_1148" align="alignright" width="150" caption="Maxxy sitting pretty in a box."][/caption]Is it weird that I'm hoping Max has HyperThyroidism? Considering the other possible diangosis' such as Lymphoma etc, I don't think so. As I type this I'm awaiting the results from Max's T3 Suppression test.

The past two years or so my smokey grey cat, Max, has not been feeling quite up to par. He's had bloodwork and urinalysis done several times, a few sets of xrays, physical exams etc but we have not been able to pin point what's going on with him.

When I look at Maxxy, I see a stereotypical HyperThyroid cat, although his T4 and FT4 by Equilibrium Dialysis tests came back within normal ranges more than once. Some of his symptoms include weight loss despite having a great appetite, he was vomitting his raw food immediately after eating because he was so ravenous and eating so fast but I solved the vomitting by adding canned food to his raw so it slows him down, he has a bit of muscle wasting in his back end, he possibly has high bp, he seeks out cold spots to sleep in areas of the house that he never went to before, his meow changed (almost as if he's losing his meow and he makes an oy oy oy sound), he's more vocal when he makes that strange sound, he paces, etc. [caption id="attachment_1147" align="alignright" width="150" caption="Maxxy Playing!"][/caption]That all sounds pretty awful when I list it like that but Max still looks good. If you just met him you wouldn't realize he's lost weight because he's still about 10 lbs but I know that Max used to be about 14 lbs so that's a big drop for him over the last two years. Max's fur still looks nice and he still purrs and gives me head butts when I pet him and groom him and love him up.

In older cats, the normal range for T4 is lower than in younger cats so this adds to the confusion when trying to determine if an older cat is HyperThyroid. Also, the T4 results can come back within normal ranges if they have concurrent health issues (some diseases can depress the T4) and considering Max is now 19 yrs old with a lot of symptoms he still may have HyperThyroidism even though his T4 levels are within norm. So, to finally rule HyperThyroidism in or out, we did the T3 Suppression test.

Based on what I've read about this test on several different websites and based on conversations with other knowledgable cat guardians who have been in the same situation with their cats as I am with Max, the T3 Suppression test is the best test for truly determining if your cat has HyperThyroidism. Of course, it can come back in a grey area as well but that's not usually the case. The only other accurate test available is a Scintigraphy, a scan of the thyroid (which should always be done before doing the I-131 treatment!) but that procedure is only done at specialized clinics and the closest clinic to me is about 3 hours away and since Max doesn't travel well, I opted for the T3 Suppression test instead.

The T3 Suppression test involves taking baseline T3 and T4 blood tests and then giving your cat 7 doses of a T3 medication called Liothyronine every 8 hours and then repeating the blood tests for T3 and T4 four hours after the last pill. The medication has to be given every 8 hours on the dot. Max took his pills at 9:30 am, 5:30 pm and 1:30 am for two days. If Max is not HyperThryoid than his T4 level will decrease after giving him those meds for two days. If he is HyperThryoid than there will be no suppression of his T4.

Today, I have the results of Max's T3 Suppression test and yes, he is HyperThyroid as I suspected all along! Now the tricky part is to determine how best to treat him, with Tapazole (meds) or I-131 (radioactive iodine). The meds will not cure the disease but the I-131 will. The problem is that treating HyperThyroidism can unmask other diseases such as kidney disease and with Max's renal numbers being slightly elevated the past few years we could possibly make his kidney disease worse.

With the HyperThyroidism Max has excess levels of thyroxine circulating in his body which actually increases the blood flow to the kidneys making it an advantage if the kidneys are imparied. The I-131 treatment would completely eliminate the thyroid disease and would therefore stop the excess thyroxine so the kidney problams could in all likelyhood become more serious. Right now he's doing fine in that regard except the slightly elevated levels. It's a tricky situation but from what I've read and from what my vet has said, treating with the meds might be better in Max's case to ensure we are not causing more problems for the kidneys and we can adjust the meds accordingly to make him feel better from the HyperThyroidism without aggravating the kidneys. Bloodwork will have to be done to evaluate how he's doing as well as me keeping a very watchful eye on him for any positive changes and for any negative changes.

Now at least I know what Max's main health problem is and I'm glad it's HyperThyroid as opposed to some of the other more serious diseases that were being tossed around. I'll post again with an update on his treatment.