I would be grateful for advice please.

My 7-year-old entire male Cocker is going tomorrow for a blood test for hypothyroidism.  I have seen from previous posts that I need to ask for T3 and FSH as well as T4 testing - are there any other questions I need to ask, or can any recommend a reliable and authoritative website.  I have just spent time going through google results, and am really not sure what is trustworthy and what isn't.  I want to be able to have a reasonably well-informed conversation with the vet about this.

Thank you.

My eleven yr old was tested just four months ago....she had loss of coat,lethargy,weight gain...in Italy they tested only the tsh and t4.... The results were so extreme (hypothyroid)that she went on 700mg of eutirox straight away...now after the first month,she was re-prescribed a lesser dose of 400 mg a day. /she weighed 24 kg. (bloated wt) and within 3 weeks came down to 20 kg ( lean and fit).
She has changed from a washed out cream to a deep red,with all her new hair growth...she's much more energetic ,and this has been a lifesaver.She also has ibd and other issues with her kidneys,so at least this is one less worry.
good luck with your boy....myvet took an age to be convinced mymdog needed testing....she blamed the steroids for her wt gain etc...:(

Thank you.  I'm so cheered to read about the quick improvement in your girl when she started the medication. :)
My poor lad has been shedding his coat, put on weight and can't lose it, has begun to have testicular atrophy, and has had three separate instances of skin problems, and acts like an old dog.

Good luck...we began to see changes within the first week, so I hope you too have the same results.
My poor girl has had health issues all her life..but at least this one was something we could see an instant improvement with.

You need to try and get Total T4, free T4, total T3, free T3 and TgAA antibodies as a minimum.  Anything less is not sufficient for diagnosis.  A lot of vets here can't get everything though, at the least try to get the free values of each in preference to the total, as this is what's actually available for the body to use.  It's important to get the T3 as if there is any conversion problem (T4 gets converted to T3 so the body can use it), a T4 only or T4/TSH or TSH only test will not pick it up.  It's rare in dogs, but it does happen - one of mine has this problem.

TSH is next to useless in dogs - the vet will doubtless try to persuade you otherwise, but don't be fooled.  There's no exact figure, but roughly 20-40% of hypothyroid dogs have a TSH within range; Remy (my conversion issue dog) has always, always had a normal TSH.  It took me three years to get him diagnosed because the vets don't know how to do it properly, and it was me who finally cracked it.

Ideally, you want to send samples off to the US for testing - Hemopet do a full panel, Michigan State Uni do a more thorough full panel, but it takes a little organising and a lot of vets aren't keen on doing it for some reason.  Mine have never argued about it but a friend of mine has spent years trying to get them to do it and all the vets he's seen have refused!

If you want some vet-written information have a look on itsfortheanimals.com, look for the hemopet/Dr Dodds info - there are articles there on diagnosis, treatment and symptoms.  Googling Dr Jean Dodds will find some info too, she is the foremost authority on thyroid problems in dogs.  In each of my four hypo dogs, it's been her that has helped me persuade the vet at the time to trial them on medication.

On that note - when you get the results, get the numbers, the reference ranges and the units - Dr D can do interpretation for you.  Do NOT accept 'normal' as a result, this is a misnomer - it simply means that the result is within the lab's range.  All four of my dogs were within range at first testing, which is why Remy took so long to get diagnosed - the other three were almost straight away but by then, I knew what I was looking at and was able to push for treatment.

my mini schnauzer has an under active thyroid, which was diagnosed back in April.
She has half a thyrofon tablet twice a day with food.
It has made a huge difference to her, before she was pretty inactive, could not seem to loose any weight and had bald patches and thinning fur.
We started to notice some improvements within about 4 weeks.  Her fur has now regrown, her energy levels are much improved and she has lost weight too.
wishing you good luck with your dog

That reminds me of a point I'd forgotten - if you do end up trialling meds, you need at least a four week trial, a six week is better as it takes time for the hormone to build up in the body and for any 'damage' already done from lack of hormone to be rectified.

Thank you very much, Nikita, that's very helpful.  He's had his sample taken and I've made sure to ask for everything to be tested. Now to wait for the results.

AnnM and Bellamia, thank you very much for your encouragement.  I hope my boy will soon regain his health as yours have done.

Just updating - very many thanks to everyone who offered help and support with this.  :)

My boy's blood tests came back showing thyroid levels just below normal.  He was started on Leventa five weeks ago, and is doing well.  He has started to loose his excess weight, and his testicles, which had begun to shrivel, quickly went back to normal.  His demeanour, which had been very subdued and not what it should have been (he's a Cocker), has improved greatly and he has regained his zest for life and cuddles, and is interacting more positively with my younger (18-month-old) dog. 

There's still more weight to loose, and more gloss to come back on his coat, but so far he's doing very well. :)

Merrypaws - that's good news, glad to hear that he is responding well with the thyroid treatment

Brilliant, glad he's on the mend :-)