Thyroid testing - basic question

RE: Thyroid testing - basic question

niamhjl — Mon, 20 Dec 2021 22:23:31 GMT

[quote userid="11308" url="~/001/veterinary-clinical/small-animal/medicine/f/discussions/30114/thyroid-testing---basic-question/234621#234621"]Have a recently diagnosed case where there is no way the owners could do a home curve on their cat ( they can barely do the injections) so decided to monitor via clinical sings and intermittent fructosamine. Attempted a curve in our hospital but abandoned after 3 samples because the cat was so stressed.[/quote]

This should probably be a tangent, but have you ever tried a freestyle libre in these cases? I have found it to be a game changer and it has pretty much replaced hospitalised curves for me now. Just have the pet in to place the sensor (very easy) and send home with the owner. They can either use the specific device, or use an app on their phone, literally wave their phone over the pet to get a BG reading. Works very well. We usually get them to monitor for 2-3 days at a time before removing the sensor so you get some good data.

RE: Thyroid testing - basic question

Clive Ansell — Mon, 20 Dec 2021 12:08:06 GMT

[quote userid="11308" url="~/001/veterinary-clinical/small-animal/medicine/f/discussions/30114/thyroid-testing---basic-question/234621#234621"]

I think we can extend this discussion on bloods monitoring to most chronic medication:

1) long term NSAIDs

2) Apoquel

3) Furosemide (to check electrolytes)

4) Diabetes (how often do you ask for a curve?)

[/quote]

Good idea.

General answer; it depends on the case and the client.

I don't really like the current trend of testing every 3 months because it's protocol, and in some cases refusing to prescribe medications if tests are not done.

1. I like to get baseline bloods initially, but don't really push for after that unless there are any findings on c/e to warrant it. Once a year maybe. I take the view that nsaid are either needed or not.

2) don't unless and clinical findings indicate it.

3) Not usually, maybe if on very high doses of diuretics or if any clinical findings indicate it. Ones I do are usually recommended by referral clinicians for referred cases.

4) Every 3 months ideally, but better if done by owners. Prefer fructosamine for stressed or stroppy cats.

[quote userid="11308" url="~/001/veterinary-clinical/small-animal/medicine/f/discussions/30114/thyroid-testing---basic-question/234621#234621"]Saw a dog at one of our branches that has been on Vetoryl for years and hasn't had even a pre-pill test done for at least 3 years, owner keeps refusing. [/quote]

I had a case like this prior to covid lockdown, where the a dog became ill and eventually collapsed because it had become Addisonian. Finished up one weekend in an OOH clinic with a multi £1000 bill. I was one of 3 vets mentioned in a written complaint because we didn't push hard enough to persuade the owner to run monitoring bloods, even though she admitted they were offered but she declined them based on costs!

Take home lesson from that was always point out the risks of not running an advised test, and if declined make sure it is entered in the clinical notes. In fact if its a case I feel uneasy about I will email myself, or print off, a copy of the notes (Once had a practice owner edit my notes in favour of a client following a complaint!).

RE: Thyroid testing - basic question

Anthony Dennison — Mon, 20 Dec 2021 10:18:26 GMT

I think we can extend this discussion on bloods monitoring to most chronic medication:

1) long term NSAIDs

2) Apoquel

3) Furosemide (to check electrolytes)

4) Diabetes (how often do you ask for a curve?)

My answers:

Hyperthyroid cats - maybe once or twice a year once stable, unless clinical exam give me any concerns. If owners refuse I can't do much about that. Saw a dog at one of our branches that has been on Vetoryl for years and hasn't had even a pre-pill test done for at least 3 years, owner keeps refusing.

1) will usually do them when starting just to make sure no serious issues, but other than that maybe once a year? Ancient dogs that rely on it I won't often push for testing if owners decline, I'd rather a dog be pain free for a shorter period of time than live longer in discomfort.

2) Supposed to do a haematology annually as monitoring, I will do if not done for a couple of years but usually one of my colleagues has done it already

3) Don't unless issues

4) If stable, I mainly rely on clinical signs of the animal, maybe do a curve every couple of months. If people want to do them at home more regularly that's great. Have a recently diagnosed case where there is no way the owners could do a home curve on their cat ( they can barely do the injections) so decided to monitor via clinical sings and intermittent fructosamine. Attempted a curve in our hospital but abandoned after 3 samples because the cat was so stressed. I figure it's better than nothing. I always recommend home curve testing and remote management for DM cases as it's easier for the pet and cheaper for the owner.

RE: Thyroid testing - basic question

Neil Wheadon — Sat, 18 Dec 2021 17:00:46 GMT

[quote userid="5012" url="~/001/veterinary-clinical/small-animal/medicine/f/discussions/30114/thyroid-testing---basic-question/234562#234562"]How often are folk testing hyperthyroid cats once stable on medication?[/quote]

In all the practices I work in, it is usually every 6 months and the protocol is usually driven by the clinical lead. Personally if it's a younger cat maintaining weight and dong well, then I'm happy to do it annually if not longer

[quote userid="2235" url="~/001/veterinary-clinical/small-animal/medicine/f/discussions/30114/thyroid-testing---basic-question/234563#234563"]I don't think rigid protocols are appropriate.[/quote]

Fundamentally agree with this, but a look at renal function is important, so maybe do a UPC / Specific Gravity as well.

Neil

RE: Thyroid testing - basic question

Rob Davis — Sat, 18 Dec 2021 16:44:45 GMT

Depends on clinical signs - I don't think rigid protocols are appropriate. I think very few require three monthly testing as the drug companies suggest...

RE: Thyroid testing - basic question

Clive Ansell — Sat, 18 Dec 2021 16:37:26 GMT

[quote userid="5083" url="~/001/veterinary-clinical/small-animal/medicine/f/discussions/30114/thyroid-testing---basic-question/234558#234558"]In a similar vein a clinic I was a locum at recently insisted on all hyperthyroid cats having their monitoring bloods taken 4-6 hr post-pill.[/quote]

I've come across a small number of practices that do this, although most don't. I never have, but if a practice does, I just go along with it.

How often are folk testing hyperthyroid cats once stable on medication?

RE: Thyroid testing - basic question

Lucy Fleming — Sat, 18 Dec 2021 16:22:07 GMT

[quote userid="8991" url="~/001/veterinary-clinical/small-animal/medicine/f/discussions/30114/thyroid-testing---basic-question/234524#234524"]Is that American site still around that thinks hypothyroidism is source of all evils of veterinary medicine? As in every dog probably has it "subclinically"?[/quote]

Do you mean Jean Dodds? "All dogs are hypothyroid but you can only properly diagnose it through our labs and fix it with our treatment and just do what I say and ignore the vet that actually has your dog under their care"....that one? Still around, actually just been sued for practicing vet med without a license...

RE: Thyroid testing - basic question

Yantha Smyth — Sat, 18 Dec 2021 13:19:08 GMT

In a similar vein a clinic I was a locum at recently insisted on all hyperthyroid cats having their monitoring bloods taken 4-6 hr post-pill. I had not come across this before in cats, and have tended to say it didn't matter what time the test was done. I don't recall having seen this in data sheets for the various hyperthyroid meds, or perhaps I have missed something the whole time?

RE: Thyroid testing - basic question

Clive Ansell — Sat, 18 Dec 2021 10:03:40 GMT

[quote userid="8958" url="~/001/veterinary-clinical/small-animal/medicine/f/discussions/30114/thyroid-testing---basic-question/234527#234527"]Quite interesting as the results were 23 and 27, 3 and 9 hours post pill (given BID) which suggests that even though the dog was doing really well, it was being underdosed?[/quote]

So, what did you do? increase the dose or not?

You said just started therapy, how long ago?

On what tests was the original diagnosis made?

Would a TSH test be useful in such case. one would expect it to be high if genuinely being underdosed.

How often do folk routinely test these cases once they are stable?

RE: Thyroid testing - basic question

Neil Wheadon — Fri, 17 Dec 2021 23:10:00 GMT

This is from Michigan State https://cvm.msu.edu/vdl/laboratory-sections/endocrinology/thyroid-medication-and-monitoring

On a BID protocol we hope to achieve values at the top or slightly above the reference range at the expected time of peak concentration (approximately three hours post pill) and a value within the lower half of the reference range if sampled just prior to the administration of the next pill (trough concentration).

Quite interesting as the results were 23 and 27, 3 and 9 hours post pill (given BID) which suggests that even though the dog was doing really well, it was being underdosed?

(We did 9 hours post pill as that was the latest we could do as the owner had decided to treat at 0800 and 2000)

Neil

RE: Thyroid testing - basic question

David Mills — Fri, 17 Dec 2021 22:50:14 GMT

We rarely if ever test, but go off clinical signs/response. I always thought t4 wasn't a great measure of 'control' given the multitude of factors that could affect it. The. again I'm cynical about overdiagnosis of hypot4.

Is that American site still around that thinks hypothyroidism is source of all evils of veterinary medicine? As in every dog probably has it "subclinically"?

RE: Thyroid testing - basic question

Clive Ansell — Fri, 17 Dec 2021 18:59:19 GMT

Another one for 4-6 hours post pill.

I'm guided by, and interpret blood results in light of clinical signs. If the dog is clinically stable I tend to take the if it ain't broke don't fix it approach. I'm not convinced having peak and trough levels would be anymore useful?

RE: Thyroid testing - basic question

Nick Jackson — Thu, 16 Dec 2021 17:14:03 GMT

Ive always done 4-6 hours post pill, if they have been diagnosed as hypo properly doesnt seem much point in measuring trough, much less charging twice as much.

Though if the data sheet says it .... ?!?!

RE: Thyroid testing - basic question

Utlendigur — Thu, 16 Dec 2021 13:10:23 GMT

I've usually done 4-6 hrs post pill - idexx guidelines for peak levels, but thyforon data sheet does say 3hrs + pre-pill. I can't ever remember doing a trough level for hypothyroid cases. It would be interesting to see what variation there is and whether there are many (any?) that are within range on peak but below on trough level especially since it's BID dosing