hi all -- i'll TRY not to wander on endlessly here, as i feel like a veritable font of knowledge on this topic right now, but..... to summarize: 1 - orion's behavior, gradually, starting around the beginning of the summer, began to change (i had posted a few things about that, thinking it was purely behavioral). 2 - it escalated recently (excessive grumpiness/irritability, fearfulness, anxiety, etc.). 3 - he has begun to lose hair in certain spots (inside/back of rear legs, sparse on his belly, lower back has the beginning of a reasonably large bald spot). 4 - he has been increasingly gassy (no change in food or treats or environmental factors). 5 - he developed a skin infection on the skin around his groin area (the area that's normally not very hairy). 6 - his skin is starting to get darker in some spots (hyperpigmentation). so... me being me, i did reams of research, and everything (even the unexplained growling/fearfulness) pointed DIRECTLY to a thyroid issue - specifically, hypothyroidism (insufficient thyroid hormone). apparently, it's VERY common in labradors (who knew - i didn't!). so off we went to the vet - i presented her with my laundry list (above), anecdotal evidence, and she observed his behavior for herself - he ran in quite happy and wagging, and ran to her to be petted, and then when she squatted down, he suddenly became quite fearful, growled (mouth closed), ears down, eyes THIS BIG, and backed up until he reached the door, then sat there, whimpering sadly. so she SAW it for herself... not just a paranoid puppy mama. he has done this with others, too - whether they crouch down or not (i thought perhaps it was just the movement that frightened him, but it happened with someone else while they were standing up and never moved). i had thought thyroid primarily affected older dogs, but found much research online saying it has been happening more in younger dogs, and many times, the symptoms coincide with the onset of puberty (which maps directly to the age at which i began noticing issues over the summer), so owners will often dismiss it as hormones or behavior issues. research also indicated thyroid levels in dogs are at their absolute peak between 6-12 months of age and then very gradually declines over a dog's life (just like a human's life)... which makes perfect sense. so the vet ordered a complete blood panel and added in a free t4 test as well at my request (CBC only tests t4, not free t4 - i would have liked to have a panel test EVERYTHING but i didn't have the money).... i was 100% positive it would come back and show a thyroid deficiency. guess what? it didn't. it showed him within "range" - below the 50% mark for both (and in the lower third for free T4)....so here's my thinking. i have nothing to compare this with - i have no baseline - this is the first time he's ever had blood drawn.... but it SEEMS to me, given his age, his thyroid measurements (especially free t4) should be higher than the midpoint. his regular t4 was right around midpoint, but free t4 was at the low end of the range. so he's "low normal" - which, in a dog as young as he is, could actually be a BAD thing (given the symptoms). so back online i went... and i found out that many times, in dogs that are at the beginning stages (very young or very early on) will not show weight gain (a classic symptom), nor will they necessarily be "below" where they should be on the measurements on bloodwork... but will simply be "low normal" - but that it's a prime opportunity to get in and handle it before it gets worse. so all of that to ask this... does anyone have any input as to what a labrador puppy's free t4 reading and t4 reading would normally be at this age? he will be a year old in a week and a half... and i keep reading that it's important to compare thyroid results with others of the same/similar breed and age. i can't help feeling something is NOT RIGHT here. his free t4 seems too low for a dog of his age.... and that, combined with all the symptoms, and his behavior change..... am i delusional?
Re: Thyroid Hi Paula, no I don't think you are being delusional at all . We spend 24/7 with our dogs and notice even the smallest of changes in behaviour . Its a sort of Motherly instinct , similar to Mums knowing when their child isn't well even when the Doctor says otherwise . I`m sorry but I don't know enough about thyroid issues to be able to help, but my advice would be to go with your gut instinct and go back to your Vet , good luck x
Re: Thyroid Hi Paula. Hypothyroidism would be uncommon at Orion's age, and given that his results are currently normal I would be very cautious about over-interpreting the fact his values are in the lower half of the normal range. Thyroid hormones concentrations fluctuate quite a lot throughout the day hence there is a big normal range - the laboratory I use that range for TT4 is 13-52nmol/l which as you can see is a big range. Nonetheless, a dog with a concentration of (say) 17nmol/l is still within the normal range. There is no evidence that being in the bottom third of the normal range is significant - it is a big range because of daily fluctuations anyway. Because of this issue, fT4 MAY give a better idea of what is happening but really it is again a snapshot photograph of what is a moving video of thyroid hormone fluctuations throughout the day. A thyroid function test (TSH stimulation test) may be useful - take a baseline sample, inject TSH to stimulate his thyroid, sample again 6 hours later and compare the two but there have been supply problems with TSH in the UK at least. You can measure lots of other thyroid hormones and autoantibodies if you want, but it gets expensive and in essence you have 2 normal tests (TT4 and fT4) in a young adult dog and I would call that as very unlikely he is hypothyroid. If he were my dog, I would not chase a diagnosis of hypothyoidism at this stage. At the absolute most I would repeat samples in 2-3 months. When teaching veterinary students I always used to tell them that hypothyroidism is known as "The Great Imitator" - it can look like almost any disease, and almost any disease can look like it. Again, the adage "common things occur commonly" is very true, and hyperpigmentation, skin infection and hair loss in a 1yo lab is much more likely to be parasitism or allergy than it is hypothyroidism. It is probably worth noting as well that there is a syndrome known as "euthyroid sick syndrome" in which lots of other diseases and certain drugs will give a dog low normal concentrations for thyroid hormones and whilst theoretically fT4 should be less affected, in practice it frequently is. So I would agree with Kate. There is clearly something wrong with your boy to cause the symptoms you have detailed, but it is unlikely to be hypothyroidism from the information you have given and I would also recommend you go back to your vet for a chat about chasing other diagnoses for his problems. Hope this helps.
Re: Thyroid I can't help I'm afraid, but echo what skate and Lochan have said about going back to the vets to try and find out what is going on with him. Good luck and let us know how you get on
Re: Thyroid thank you all! lochan, your reply was terrific - good to know there's other stuff out there that could be causing the issue. i have the complete bloodwork results showing everything... would it help if i posted it here? what other things could possibly cause these symptoms? i just want to figure it out and fix it so he can be his usual self again.
Re: Thyroid I don't have anything practical to add but just wanted to say that I hope you get to the bottom of it. I know it must be a big worry. Thinking of you and Orion.
