To start thyroid Tx?

Re: To start thyroid Tx?

Rajat — Fri, 21 Sep 2012 18:41:19 GMT

[quote user="David Mills"]

[quote user="Martin Atkinson"]

Reach for the can opener!! IMO a cat with raised BUN & Crea plus a urine SG of <1020 has renal disease whether or not it has proteinuria and will benefit from ACEi to lower intraglomerular pressure and slow progress of the renal disease towards renal failure as well as reducing urine protein loss. Why wait until it is in renal failure?

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As I'm sure you're aware, several recent studies have shown no - none, zero, nothing - evidence whatsoever for the use of ACEi in renal disease without proteinuria. No structural protection, no nephon-sparing, no increase in survival time, no change in renin or aldosterone activitity, no reduction in BP. The only thing ACEi have been shown to do is increase appetite when preoteinuria is present - they don't even drastically or reliably reduce proteinuria.

It appears, not simply from an anecdotal opinion, that there is no evidence for ACEi usage in cats with renal failure, with or without proteinuria. Assume people who do use them, that your clients are aware of this experimental/client-funded research?

As for BP, at best they will reduce it by 10mmHg. Which isn't going to save any retinae.

[/quote]

100% with David here. There is no evidence that ACE-I will help CRF cats without proteinuria. No point in using it!

Re: To start thyroid Tx?

Rob Davis — Fri, 21 Sep 2012 18:07:05 GMT

[quote user="Martin Atkinson"]This is IRIS stage 1 CKD[/quote]

[quote user="Robin Grimmer"]The low SG and increased urea is evidence of chronic renal disease, so I would recommend starting a renal diet[/quote]

[quote user="Martin Atkinson"]IMO a cat with raised BUN & Crea plus a urine SG of <1020 has renal disease[/quote]

Am I missing something here? I read it that the urine sample was obtained at a later date after the blood sample was run. Surely unless they were run concurrently, we cannot say whether or not there is any renal dysfunction.

Re: To start thyroid Tx?

David Mills — Fri, 21 Sep 2012 00:50:09 GMT

[quote user="Martin Atkinson"]

[/quote]

As for BP, at best they will reduce it by 10mmHg. Which isn't going to save any retinae.

Re: To start thyroid Tx?

David Mills — Fri, 21 Sep 2012 00:43:24 GMT

This is a very good article, accessible if you're a BSAVA member describing your exact situation:

http://onlinelibrary.wiley.com/doi/10.1111/j.1748-5827.2008.00544.x/abstract

That is the cut off of hypert4 in CKD seems to be lower, at 30, for most cats; and that TSH is usually the way to go.

If I was you, I'd start to treat the hypert4, retest 2-3 weeks if renal figures OK start amlodopine.

Re: To start thyroid Tx?

Martin Atkinson — Thu, 20 Sep 2012 19:02:25 GMT

This is IRIS stage 1 CKD so I would just give a protein reduced diet but maybe just a senior diet (RCVC senior Consult stage 2 High Calorie would be my choice) rather than renal diet, with a T4 of 57, raised ALT and your symptoms there is enough IMO to justify commencing medication with Felimazole or Vidalta if that's preferred, but ideally it still needs to be monitored to make sure renal function doesn't deteriorate

Re: To start thyroid Tx?

Kathryn Burton — Thu, 20 Sep 2012 18:21:27 GMT

Creatinine 114 umol/l.

Re: To start thyroid Tx?

Rob Loxley — Thu, 20 Sep 2012 17:05:23 GMT

What was the creatinine value? Many lab normal ranges include IRIS stage I

Re: To start thyroid Tx?

Alice Courtney — Thu, 20 Sep 2012 14:35:45 GMT

(sorry I forgot you said you didn't think a BP reading would be possible! Not even after some zylkene & feliway in a cosy kennel with a gentle nurse? Or with the owner in the consult room?! No, OK, one of THOSE cats!). Agree with others that all you can do in cases like this is advise of the best course of action, give the owner some options, and the rest is up to them to chose what they want for the cat...

Re: To start thyroid Tx?

Alice Courtney — Thu, 20 Sep 2012 14:33:02 GMT

If ALT is not convincingly elevated & no palpable goitre then it would be nice to get a fT4 to confirm hyperthyroidism before treatment, but it seems a possible. As others have said, if not then repeat examination/T4/ALT in 3-4 week's time.

Ideally get a BP reading, & repeat this after you have started treatment for hyperthyroidism if this is present.

UTI is relatively common in hyperthyroid cats I think, so with that USG I would ideally want to get a C+S (or as you say a 2w course of ABs if cysto not allowed!), particularly since E.Coli UTIs make cats go ga-ga & show dementia signs. I would run a UPC at the same time if costs allow, since if UTI is absent it will provide you with prognostic information if nothing else. Hope that helps.

Re: To start thyroid Tx?

HMC — Thu, 20 Sep 2012 13:45:09 GMT

I have started cats on hyperthyroid tx at lower t4's than that but only when there is a high suspicion of hyperthyroidism- ie a palpable goitre. I started two cats on 2.5mg felimazole sid and got brilliant results despite the low dose.

However, in this cat's case I think I'd try antibiotics (clinical signs consistent with cystitis, low usg, older cat so more likely to be infectious rather than idiopathic cystitis). Then repeat bloods and urinalysis.

t4 usually increases well over time so a second sample a month later may shed more light on the thyroid.

Re: To start thyroid Tx?

Kathryn Burton — Thu, 20 Sep 2012 13:34:25 GMT

Further details on the case:

- CE mild calculus, grade 3 heart murmur, weight loss, no palpable goitre, mild miliary dermatitis and fleas

- biochem urea 16.9 mmol/l, ALT 90 u/l, TT4 58.3, otherwise unremarkable

- since blood test urinating in house, howling, outdoors rather than indoors, no changes in appetite/thirst that O aware, toilets outside

- free catch urine sample leuco +++, pro trace, poss trace blood, USG on refractometer 1.018

Re: To start thyroid Tx?

Martin Atkinson — Thu, 20 Sep 2012 12:46:13 GMT

[quote user="Robin Grimmer"]I don't think there is any indication for benazapril as there is no proteinuria and on its own it is not very good at reducing BP.[/quote] Reach for the can opener!! IMO a cat with raised BUN & Crea plus a urine SG of <1020 has renal disease whether or not it has proteinuria and will benefit from ACEi to lower intraglomerular pressure and slow progress of the renal disease towards renal failure as well as reducing urine protein loss. Why wait until it is in renal failure? And admittedly ACEi's are not spectacular as anti-hypertensives but they have some action especially where we're not even sure this cat is hypertensive. I've had more than one case which has gone hypotensive on benazepril alone and had to reduce the dose to brighten them up I wouldn't like to think what amlodypine would have done.

Re: To start thyroid Tx?

Robin Grimmer — Thu, 20 Sep 2012 11:28:55 GMT

The low SG and increased urea is evidence of chronic renal disease, so I would recommend starting a renal diet. I wouldn't start on any thyroid treatment yet, but I would retest the T4 in a month. The possible hypertension is a tricky one. I would try a BP, you could admit her for the morning and have a few attempts. If you can't get a BP, I would probably monitor the retinas for now, and start amlodopine if there are any signs of retinal haemorrhages or detachments.

I don't think there is any indication for benazapril as there is no proteinuria and on its own it is not very good at reducing BP.

Re: To start thyroid Tx?

Thomas Johnson — Thu, 20 Sep 2012 11:03:26 GMT

My understanding is that the leukocyte test on urine dipsticks is completely unreliable for cats and often gives false positives, so if the red blood cells and protein is negative I would probably discount cystitis and not worry about antibiotics.

If the owner will agree I would probably repeat the urea, creatinine and T4, and if still not sure about hyperthyroid request a free T4 on the same sample.

Re: To start thyroid Tx?

Martin Atkinson — Thu, 20 Sep 2012 09:18:44 GMT

Given the huge variation within the normal T4 range this cat is probably hyperthyroid but you could try a vet specific FreeT4 by immunoassay from Idexx which doesn't cost too much. I've seen several hyperthyroid cats with T4 levels at this level (including my own). As to how you balance therapy with the management of renal disease is up to the individual case but I would at least try and measure BP before I put it on amlodipine, benazepril may be more appropriate given the renal disease and in combination with treatment for hyperthyroidism may be enough to normalise the BP if it is raised anyway. I find Felimazole is more manageable than Vidalta but that's a personal choice. Given the owner is as difficult as he/she seems to be you can only recommend the best course of action and its then their choice, you are approaching this case with the correct mindset so don't hit yourself over the head with it. If monitoring is not allowed you can tell them you can do no more or put it on a low dose of Felimazole (2.5mg bid) and Fortekor with renal diet and it will probably do as well as can be,