My bullmastiff was diagnosed with hypothyroidism two weeks ago. She didn't have all the classic symptoms, but did get the odd skin infection, always hard to keep weight off, panting alot, but the main thing she seemed grumpy with our other dogs and some dogs out which is really out of character for her. These can be some of the vague symptoms so decided to check. T4 was low and TSH was high so have started her on soloxine. I think I was expecting some dramatic difference in a week or so but haven't noticed anything yet, does it take alot longer? She had another panting episode yesterday for most of the evening, is this related? She has been vet checked several times (I work there!) and we know she has arthritis in her knee joint after a tplo las year, she is on metacam daily and tramadol if needed. I knew something wasn't quite right with her for a while and when we found the under active thyroid thought at least that's something I can help her with, any experience with this condition or any other advice most gratefully received.
Thank you
Catherine

I seem to remember it took about 4 weeks before I noticed any differences, and 2-3 months before my bitch was back to normal. (The excess weight lost, the coat grown back, the tiredness gone.) She's 100 % normal now and has been on it for 3 years. And yes she panted as well, that went.

The psychological effects were very quick with my dog, within a week he stopped being aggressive. The physical symptoms take longer, around 4 weeks if I remember correctly.

You will need to recheck monthly or so until the right dosage of soloxine is found as well which is important. Personally I would also ask for a comprehensive thyroid check, not just the basic one which your dog had. That would give you and the vet more information.

Hi, I have an American Cocker on Thyroid meds. Kitty was on Soloxine to begin with now on Forthyron, and I noticed a big change in her mood and demeanor within the first 3 days, it was quite amazing really. She was 4 years old at the time and had become like an elderly dog, fat and miserable, with no enthusiasm and always ravenously hungry. Kitty is now 10 1/2 and has been just like a puppy again for years. It's only her grey face that gives her age away.

Dawn R.

If I remember rightly (and we're going back nearly 4 years here, so it might be a wee bit out) I think Soli's took about 3 or 4 weeks to kick in properly.  Did nothing for her personality - that was all upbringing and genes - but her coat and weight improved nicely in that time.

Remy never improved on it but then Remy is an odd bod, and is now on T3 (the converted product of thyroxine) which is working.

My bullmastiff was diagnosed last year and its a constant battle with my vets. He is a little perkier on soloxin but not his "old self" he hasnt lost the weight he gained and he now has black pigmented skin appearing. This was checked and bloods were done and they upped his dosage but i find they up it for a while then reduce it again as his bloods show he is back within normal range and on the high end. However if that were the case surely he would be back to his old self. He isnt grumpy, he just seems lethargic and depressed as well as being fat and his hair has never grown back or the pigment of his skin changed. I am looking into homeopathic remedies for my boy as i hate having him on meds like this, i've contacted a homeopathic vet who hopefully will give us some answers. I find it very hit and miss with soloxin and just want my boy back :(

Get a full panel done by Dr Dodds (Hemopet), and emphasise that the soloxine isn't working.  Send a list of his symptoms, and talk to her yourself - Remy's last report came back with just the recommendation to reduce his soloxine dose and no mention of his symptoms (done by different vet), so I emailed to discuss - and progress was made.

I have been through this with Remy - he does not respond to soloxine AT ALL.  Not for the 3 years he's been on it, not at any dose.

The reason for that is that he doesn't convert it properly into T3 (which the body uses) - so the T4 just builds up.  On his last panel, his T4 was more than double the top end of the range.

He is now on T3 (which I have to buy myself from Cyprus) and although I think he could do with a dose increase, I have my old dog back - who I haven't seen properly in 6 years (it took 3 to get the diagnosis).

Bear in mind that as far as most vets are concerned, soloxine does the trick but just as in people, T4-only therapy does not suit every dog - it's uncommon but it happens.  It might also be that he would respond to a different form of T4 - I'm sure there is at least one other besides soloxine, possibly two or three.

Also, have they explained why they are reducing his meds once he's in range?  That makes no sense unless I'm reading it wrong - the thyroid doesn't get better and that's it, it needs maintaining once the right dose is reached, if it can be reached.  And, all dogs are different - some need to be higher in range to be healthy.  Remind them of that, too.

Last points - make sure he's getting it away from food (at least one hour before or three hours after) and on roughly a 12 hour schedule.  Calcium interferes with absorption and dog food, of course, has calcium in it.

It's interesting to hear Staxonoby that your bullmastiff has the same. Ruby still hasn't seemed any different on soloxine, which is frustrating. I wasn't aware that as Nikita said ' not to give soloxine close to meals' I always give Ruby's with her dinner. What dose is your boy on? Ruby is on 0.5 twice a day.

Thank you Nikita. I am taking my boy to a homeopathic vet next week, hopefully they can help. Like i said its a constant battle with my vets. I havent known them too long so i think they don't know that i have atleast some knowledge on it. It took me 3 phone calls to get them to explain the tests they had done. The reason the vet reduces it is because when he is tested he always seems to be at the higher range - my vet tells me this could make him Hperthyroid but i know this cant happen. Soloxin doesnt work that way - it would have to be an extremely high dosage for that to happen. He's been back on his .8mg and .3mg pills for a week now and already there is a difference in him. He's playing with the others and bein his usual self. He was on .8mg before this. Thanks for the info RE feeding and soloxin, like streetmutt i have never heard this. One of the other things i have been told is to not give them tap water too. This supresses the thyroid from the chlorine in the water! Will speak to my vet about soloxin not suiting him and also about the T3. Hopefully the homeopathic vet can rustle something more natural up for him though. I hate putting chemicals into his body :(

It's not the chlorine - it's the flouride.  Flouride damages the thyroid - flouride based compounds are used to treat hypoerthyroidism, it's that effective!  Tapwater won't have such a dramatic effect but long-term it can suppress functionality.  Not all tap water is flouridated mind and the amount will vary place to place - worth checking with your water provider for that one.

I'm not keen on chemicals either I must admit - I'd rather have my boy on natural dessicated thyroid (like I've just started) but as he's coming up to 9 and has lost 6 years to this, I'm now of the view that I'll use whatever works for him.  Plus, the amounts of the hormones in NDT are much lower and with doses for dogs being much higher it'd cost me a fortune :p

Quick note on soloxine - dosage is 0.01-0.02 mg/lb (0.02-0.04 mg/kg) for T4.

Dosage for T3 is 0.4-0.6mg/kg.

Also a note on antibodies, if you haven't had those tested for (excerpt from Merck Vet Manual, where I got the dosages):

Although extremely rare in dogs, circulating thyroid hormone autoantibodies (anti-T3 or anti-T4 antibodies) are occasionally detected and also are believed to reflect a state of autoimmune thyroiditis. These antibodies, which can be formed against either T3 or T4 (or both), produce a spurious increase in the apparent T3 or T4 concentrations, into the hyperthyroid range in most dogs. Of all the thyroid hormones, only measurement of free T4 (by dialysis) is not affected by autoantibodies directed at T4 or T3 because the serum autoantibodies are removed in the dialysis step. Therefore, if hypothyroidism is suspected in a dog with circulating thyroid hormone autoantibodies, serum free T4 concentration should be determined to help confirm the diagnosis.

This is why I sent Remy's bloods to Dr Dodds - her panel checks antibodies too but does the serum free T4 test too.  And of course she has breed-specific reference ranges and knowledge.