Hyperthyroid cat that already is on treatment for kidney disease

RE: Hyperthyroid cat that already is on treatment for kidney disease

Kate Richardson — Tue, 23 May 2017 21:50:14 GMT

[quote user="Martin Atkinson"][quote user="David Mills"]This. I think it's a balance as to what will kill the cat quicker. In most cases its the hypert4 so this needs managing if not controlling.[/quote]I would say the opposite, renal function can fall off the cliff very quickly whereas most hyperthyroid cats have been like it for ages before the owners even notice the symptoms and can go on quite happily. [/quote]

That's why it's important to assess each case on its own merits. And why I like to slowly introduce thyroid control and find a balance between the 2 diseases. A lot of hyperthyroid cats go unnoticed by owners because the cat is eating really well and they put the weight loss down to 'old age'. I'm not sure I agree these cats are going on quite happily. Speak to any person with hyperthyroidism, it's not pleasant. (Ok, so I know it's a cat and not a human before anyone accuses me of anthropomorphism) Constant head aches, hypertension, and aside from this imagine feeling constantly hungry and never being fulfilled. However not all cases are extreme like this, so if only mild symptoms, it may be better to monitor.

RE: Hyperthyroid cat that already is on treatment for kidney disease

dachsie_4 — Tue, 23 May 2017 18:06:43 GMT

That's interesting that one went hypothyroid.... obviously that cat also did not read the text books :P

RE: Hyperthyroid cat that already is on treatment for kidney disease

Martin Atkinson — Tue, 23 May 2017 09:05:15 GMT

[quote user="David Mills"]This. I think it's a balance as to what will kill the cat quicker. In most cases its the hypert4 so this needs managing if not controlling.[/quote]I would say the opposite, renal function can fall off the cliff very quickly whereas most hyperthyroid cats have been like it for ages before the owners even notice the symptoms and can go on quite happily.

It was significant I feel that for ages top end of normal for TT4 was 65, then Axiom brought it down to 55 which I think is more reasonable but there is evidence that above 45 may be significant especially if there is concurrent disease causing euthyroid sick syndrome. I would want my treated cats T4 to be in the teens or low 20s but there is a balance to be had and the treatment need to be juggled on the basis of repeated reviews of renal and thyroid function.

Interestingly, I'm currently treating a cat which (amongst many other concurrent problems) is hypothyroid following I131 therapy and juggling the dose of thyroxin with its renal function.

RE: Hyperthyroid cat that already is on treatment for kidney disease

David Mills — Mon, 22 May 2017 19:33:17 GMT

[quote user="Kate Richardson"]

Which disease is causing the most clinical symptoms? Do you have any urine values? Useful to check UPC and rule out bacterial infection contributing to the urea/creat levels. I often find urea elevated in hyperthyroidism, so I pay more attention to creatinine, but those values definitely point to concurrent renal disease.

Personally I would start the cat on 1.25mg felimazole sid (or equivalent dose thyronorm) and reassess 3-4 weeks both clinically and w bloods. Go slowly with dose increases, I find it allows the kidneys to 'adjust' to a slow decrease in GFR and you end up finding a balance between the 2 diseases.

Very common scenario

[/quote]

This. I think it's a balance as to what will kill the cat quicker. In most cases its the hypert4 so this needs managing if not controlling.

I wouldn't consider surgery if the renal values are raised, as in most cases you'll end up with a poorly-eating, polydipsic cat.

RE: Hyperthyroid cat that already is on treatment for kidney disease

Lucy Fleming — Mon, 22 May 2017 19:21:07 GMT

[quote user="dachsie_4"]but there you go gut feeling sometimes is right...[/quote]

In those cases you can consider running free T4. Or sometimes just wait a month or two and re-test - the numbers usually catch up eventually!

RE: Hyperthyroid cat that already is on treatment for kidney disease

dachsie_4 — Mon, 22 May 2017 18:17:56 GMT

Already on renal disease treatment, was clinically hyperthyroid last year but not on bloods so I thought must be weight lost due to kidneys, but there you go gut feeling sometimes is right...

RE: Hyperthyroid cat that already is on treatment for kidney disease

Lucy Fleming — Mon, 22 May 2017 17:56:49 GMT

I would treat the thyroid disease - there's an argument that the upper end of the reference range for T4 should be brought down to 50, so 67.8 is elevated enough that I would definitely treat.

I would look at instigating management of renal disease as well - measure urine SG, UPC and blood pressure, transition to a renal diet (while polyphagic from hyper T4 can be a good time ) etc etc

RE: Hyperthyroid cat that already is on treatment for kidney disease

dachsie_4 — Mon, 22 May 2017 17:51:24 GMT

Thank you, I was thinking along those lines, but just wanted to double check.

RE: Hyperthyroid cat that already is on treatment for kidney disease

Anthony Dennison — Mon, 22 May 2017 17:49:42 GMT

I have to say, I would have probably treated last year with a t4 of 45 if it looked like a hyperthyroid cat - 30-60 is in the grey zone but if they clinically look hyperthyroid treating is better.

I would treat as normal, but warn the owner that cats that are azotaemic before starting treatment have a shorter MST than those that are non-azotaemic. Have you done a urinalysis yet, checking USG and UPC? Depending on how much the owner will let you do, checking blood pressure once the T4 has stabilised would be a good idea also.

RE: Hyperthyroid cat that already is on treatment for kidney disease

Kate Richardson — Mon, 22 May 2017 17:48:12 GMT

Very common scenario