Can anyone talk to me about subclinical Hypert4 in geriatric cats?

Re: Can anyone talk to me about subclinical Hypert4 in geriatric cats?

Luca Poddighe — Thu, 18 Jun 2015 17:03:40 GMT

If you want to confirm it with a number in the bloods the way to go is the free T4. You don't necessarily need it as a few posters have mentioned above. Obviously you need to discuss with owner and see what they feel more comfortable with. If you have run a TT4 probably you got blood sufficient at least to run as well BUN and Creatinine to know a little bit of kidney function, associating it with a urine test. So if you have a borderline high TT4 you are in a good position to elect to wait three month and recheck or run the free T4. I wouldn't start the therapy without confirming the diagnose in any case.

Re: Can anyone talk to me about subclinical Hypert4 in geriatric cats?

ruths — Thu, 18 Jun 2015 15:46:24 GMT

I call it old cat bingo... -))

Re: Can anyone talk to me about subclinical Hypert4 in geriatric cats?

ruths — Thu, 18 Jun 2015 15:43:56 GMT

Yy- I need to know usg and BP before advising anything further Thanks for your advice-

Re: Can anyone talk to me about subclinical Hypert4 in geriatric cats?

Martin Atkinson — Thu, 18 Jun 2015 13:29:37 GMT

[quote user="robloxley"]Remember ref ranges are usually based on younger cats, hence the thought that 'normal' TT4 for older cats is lower.[/quote]Agreed, labs still quote 55 as normal but I would be suspicious if they were over 40. If you have a cat with suspected hyperthyroidism with a low/normal TT4 it is likely euthyroid sick syndrome you need to look elsewhere for a co-morbidity, notably renal disease. However, a cat with TT4 over 40 but with nailed on clinical signs would be very suspicious to me.

Like Robin I cannot remember needing to perform free T4 or TSH tests. I am pretty confident I can diagnose them with a combination of clinical symptoms, TT4, presence/lack of goitre, elevated liver enzymes and heart rate/murmur.

Whatever, don't' rush into trial therapy unless you're pretty sure and renal function isn't compromised.

Re: Can anyone talk to me about subclinical Hypert4 in geriatric cats?

Rob Loxley — Thu, 18 Jun 2015 12:52:28 GMT

Remember ref ranges are usually based on younger cats, hence the thought that 'normal' TT4 for older cats is lower. If T4 in older cat is in the higher part of the ref range, especially if compatible clinical signs, then I'd either do a freeT4 (not TSH) or consider retesting. However if they're already losing wt and showing symptoms and the blood sample is still at the lab, would usually push for the former.

http://academy.dechra.co.uk/course/view.php?id=22 is good (and free to register)

Re: Can anyone talk to me about subclinical Hypert4 in geriatric cats?

Robin Grimmer — Thu, 18 Jun 2015 12:15:58 GMT

I rarely do tsh or even free t4 in cats. If the total T4 is in the upper range I'll usually recommend rechecking in 3 months and tell the owner to watch out for clinical signs. If becomes hyperthyroid and shows clinical signs then I will treat. I can't see why you would need to do further investigation when it's sub clinical.