OK, here's my best guess as to what's going on with your girl. According to the T4 tests over the last couple of years, it does look to me like she's mildly hyperthyroid. The decreased T4 back in Nov. 09 may be the result of Euthyroid Sick Syndrome, in which a concurrent illness (pancreatitis?) can cause the T4 level to decrease. The lack of ravenous appetite may be due to the renal issues, and the lack of weight loss may be due to the apparently mild degree of hyperT currently present.

I suggest you look into having your vet send a blood sample to Hemopet for definitive thyroid testing. Dr. Dodds at Hemopet has pioneered thyroid testing procedures. If anyone can provide you with a clear diagnosis, it's her. You can read about her lab and testing procedures at the link below.

Another diagnostic possibility, if you live anywhere near a clinic that offers radioactive iodine treatment (I-131) to hyperT cats, would be to take her there for a thyroid scan.

But I think Dr. Dodd's thyroid panel would be your best bet. You may even be able to set up a telephone consult with Dr. Dodd to discuss your cat's test results to date so that she can recommend the best diagnostic avenue for you to pursue now.

Laurie

Here is a link that might be useful: Hemolife Diagnostics and Dr. Dodds

Thanks Laurie. I am slightly relieved that you think she might be only mildly hyperT-basically, what the vet told me. I appreciate your information and link to Hemolife. I will discuss it with the vet (right now out for 2 weeks). I keep monitoring her very closely. No change.
And yes, we do have a clinic nearby offering iodine treatment, so a scan might be another option.
Thank you,
Anne-Marie

Anne-Marie,

There is another complicating factor potentially at play, which is that hyperT can mask or minimize the appearance of CRF in blood tests. If your girl is mildly hyperT, it's possible that her renal issues are more severe than indicated in her current bloodwork. And if that's the case, then her increased thirst and urination could be primarily symptoms of renal problems.

In any event, I think it would be a good idea to pursue further testing to try to clarify the thyroid issue, if there is one.

Laurie

I don't think the thyroid is an issue, but I would be concerned about the kidneys. With the BUN and creatinine as high as they are, and the USG as low as it is, I'd be very concerned with CRF, not so much hyperT4. We see decreased USG at 66% kidney function lost; nothing is seen in blood values until 75% of kidney function is lost. Sounds like your girl is somewhere between 66% and 75% kidney function lost.

Some things to check:
Ultrasound abdomen to take a look at kidney structure especially. Not uncommon to see small fibrotic kidneys. But if the kidneys were enlarged (as with renal lymphoma for example) you'd want to know that for treatment and/or prognosis. Ultrasound could also pick up bladder stones, kidney stones, and other causes of decreased USG if present.

Urine culture and sensitivity: not likely to show an infection but wouldn't it be nice if a simple course of antibiotics cured her?

Urine protein to creatinine ratio: excess protein in the urine speeds the process of chronic renal failure, but there are many strategies that decrease proteinuria.

Blood pressure measurement: another consequence of kidney disease that causes more damage and speeds the process. Also there are medications to control blood pressure.

That's what I would recommend for my patients in the same situation.

First thanks, Laurie, for your valuable input! I guess I just have to face reality.. that is, kidney issues! That excessive drinking/urinating came on so suddenly that I kept looking for other issues (it is too recent since I had to face kidney problems with my boy..).
Yes, I'm starting to understand that thyroid values might be masking the real problem.

Thank you, Meghane. I thought the USG was O.K. (1.015, within normal limits) without being great. But I read that, at the lower range, it does indicate declining renal functions.
As for an infection, she did have a culture/sensitivity test, and there was NO signs of bacteria ("NO aerobic growth").

I'm slow at making up my mind, but I will contact the only holistic vet around here and will probably go with X-ray and ultrasound when our vet returns-or before, if things worsen.

I wish I could change her diet (she is a Sc. diet dry addict with a little bit of Evo dry) but she has NEVER, NEVER wanted to taste canned food. She does love the chicken I prepare for her, though. That's a real issue, and I know that changing a cat's diet when he/she is sick is the wrong time...
Thanks for all the valuable help. I'm sure I'll be back with more questions!!

Anne-Marie