Low Thyroid?

[Lucy Goosey]

I'm wondering if anyone has any experience with this. Last winter, shortly after I adopted Lucy, she developed a lung infection. The blood panel revealed at that time that her thyroid function was below normal levels. At the time, the vet said that it was probably euthyroid sick syndrome, and that once she was healthy, the levels would come back up. We had her checked again in May, and it was at 1.4something (normal range is 1.0-4.0). We decided to keep an eye on it and recheck her in six months or so.

I had her blood panel done yesterday, and the results came back today. Her T4 was 1.76 (normal range is 1.0-4.0), certainly within normal range, but at the lower end. In addition to this, her cholesterol was at 275 (normal range is 92-320), and her lymphocytes were at 4900 (normal high is about 4500), which was down from 5,000 last May.

 

She appears physically healthy; has plenty of energy, good coat, clear eyes, healthy weight.

 

However, she has displayed some fearful behavior such as fear of inanimate objects such as rocks, logs, fire hydrants, drinking fountains, etc. She also doesn't like umbrellas. She has also displayed some extreme submissiveness toward other dogs and people.

 

Any thoughts?

[AK dog doc]

How old is Lucy, and do you know what her TSH was?

 

If your vet didn't explain euthyroid sick syndrome, that just means that the thyroid hormone is being over-consumed or is otherwise not available in the blood to test because the dog has her resources tied up dealing with some other illness. That sounds correct, in your case, though if her TSH is wacky, that might point another way.

 

Hypothyroidism in dogs is most commonly from an autoimmune reaction against some part of the thyroid axis, which is commonest in middle-aged females, though any dog can get it. High cholesterol is sometimes an indicator of poor thyroid function, but not always; there are other reasons for high cholesterol, and some hypothyroid dogs have normal cholesterol. BTW, we don't generally see the kind of cardiovascular issues in dog as we see in people with high cholesterol.

 

The fearful behavior doesn't sound like it's secondary to the low-normal thyroid (though stranger things have happened); is this something that has recently developed, or was she always a bit that way about those things?

[Lucy Goosey]

Lucy is about 18-20 months old. We haven't done a TSH.

 

It's hard for me to say what's normal for her, as I adopted her when she was about 9 months old, and shortly after, she became ill, then went into heat, was spayed, etc. I've been using behavior modification techniques under the supervision of a trainer for about six months, and while I've seen improvement in specific circumstances, I haven't seen generalization.

 

My vet said that because the TSH is so expensive, generally what he does, while it might not be the best medical approach to every problem, is try the thyroid replacement and see if it helps.

[AK dog doc]

Hmmm. Must be the lab... we charge about $70 for a full thyroid panel, which includes TSH, total T3 and T4, free T3 and T4, T3 and T4 autoantibodies and thyroglobulin autoantibodies. To me that doesn't seem excessive, given the number of things I get from the profile, but every lab has its own protocols and fees.

 

At 18 to 20 months old, I'd be a little surprised if she were truly hypothyroid, though it's by no means impossible. It isn't usually an issue before 2 years of age, but never say never and always avoid always in medicine, as Dr. Howie used to say. However, according to the endocrinology experts at MSU (where we send our thyroid profiles), trial treatment is fairly benign. If is isn't needed, it'll temporarily shut down her own thyroid production, but that will kick back in if her system is normal and you withdraw the medication. One way to find out, certainly, and that's to give it a try. Your vet sounds like he's on the stick about this so far, so that doesn't seem like an outrageous idea or anything. To me it sounds as if the behavioral issues are not thyroid related - but as I say, weirder things have happened, and there's one sure way to find out. The medication is inexpensive and the experts don't feel there's a problem with trial treatment, so...

[Lucy Goosey]

Hmmm. He said something about how TSH is really hard to get now and that it's very expensive, to the tune of a few hundred dollars for one test. At least I'm pretty sure he was talking about the TSH. He also mentioned that since thyroid levels can fluctuate as much as one point, it's possible that we caught her at a low and that her high is much more optimal. It's also possible that we caught her at a high, and that at her lows, she dips below normal levels. My vet doesn't seem convinced that she's "hypothyroid", and I'm not convinced of that either. What I have read about is borderline low thyroid affecting behavior. Again I could be manufacturing a problem, which is why I'm wondering if anyone else has been through anything similar and what their experiences were.

[MrSnappy]

I had my spazz tested last year because he was heavy, and he because he has some really funky fur on his legs. His tests showed up in the normal range, but the lower end of normal. Apparently, border collies often test on the higher end of normal, so this might indicate a possible thyroid problem. But in the end, dieting took the weight off and I decided not to pursue it. I will get him retested this year.

 

I understand that you can have your blood tests sent to Jean Dodds (Link Here) and it doesn't appear to be all that expensive.

 

With my dog I opted for a full blood panel as well. We didn't send it to Dr. Dodds, but the total was less than $200.00

 

RDM

[Lucy Goosey]

Yup, we've been doing the full blood panels, and it's less than $100. It's actually a better deal than just doing the thyroid. Are you maybe talking about the full thyroid panel? I think my vet's full blood panel only includes T4; not sure. Thanks for that link. I'll be calling my vet on Monday with more questions, and I'll be sure to mention it to him.

 

AK Dog Doc,

You say it's fairly benign, but are there any potential harmful long term effects from thyroid replacement therapy? If it's pretty benign, I might opt to try it and see what effects it has on the behaviors that I'm seeing. But ONLY if I'm not doing harm to her by doing so.

 

I'm also wondering how much fearfulness/submissive behavior is "normal" for a BC.

 

I'd appreciate any further comments.

[AK dog doc]

Well, the thyroid has a feedback loop to the brain, and if the brain detects the body is in a low thyroid state, it makes TSH to tell the thyroid to make more hormone. If the brain detects the body has sufficient thyroid hormone, it doesn't make TSH, so the thyroid doesn't make thyroid hormone. So, with supplementation, you're basically telling the brain there's plenty, thanks, so it makes no TSH and the thyroid makes no thyroid hormones. If you then withdraw the supplementation, the brain notices a decrease in the levels and then resumes TSH production, which kicks the thyroid back on.

 

According to the endocrinologist at MSU, there is no significant risk of injuring the brain/thyroid axis with trial treatment (I'd like to say NO risk, but I'm paraphrasing another doc here and I don't want to put words in his mouth). I've done this a couple of times with patients that were in the grey zone - usually at the suggestion of the endocrinologist - and have never had a problem. But that's less than a half dozen cases, so not a huge number to draw from.

 

As far as the submissive/fearful behavior in BCs, I've seen a moderate amount of it in my patients and my rescue BC, Buddy. Now, I adore Buddy, but he is one weird little dog. He is very submissive with strangers and inclined to be afraid of weird things, often things that he is accustomed to - he suddenly seems to decide that that thing BITES, with big nasty pointed teeth. Sometimes, but not always, this is because the familiar object is presented in a novel circumstance, whch appears to blow his little circuits (I should point out that Buddy is the one I am pleased to refer to as my borderLINE collie, and is not a Rhodes scholar, but I think he would be this way regardless of smarts.) In addition, several of my patients (by no means a majority) have some fearfulness - a couple of pretty bad fear biters amongst them, some others just with strange idiosyncratic fears. I've only had BC's for 6 years, though - well, almost seven - so there are probably a lot of people here that have a lot more time in the saddle with that and can better advise you. I think that sometimes smart dogs can develop fears more solidly than dumb ones, since if they learn something they REALLY learn it. On the other hand, poor Buddy has a variety of nameless anxieties, so maybe that's a bad theory.

 

Anyway, maybe other members have more to say on the fear/anxiety thing across the BC spectrum than I do...?

[Tassie]

Hey SAR K9 Lucy - FWIW, my late Kelpie/Border Collie cross bitch, spayed before first season, started showing symptoms of hypothyroidism about 2 ? 2 and a half. In her case, the only symptom she displayed was bilaterally symmetrical hair loss, and yukky skin where the hair went. Back in those days, vets here didn?t have any thyroid function tests available, so when my vet sent us for a second opinion after various treatments for suspected mange weren?t working, the other vet suggested the possibility of hypothyroidism, and suggested a few weeks of trial dosing with thyroxine to see if there was any effect! There was, thank goodness, and she continued on thyroxine (human prescription ? there was no veterinary equivalent then) for the rest of her 15 and a half years of happy life. A couple of times a locum at my vet?s tested her ? and she seemed to need to be at the high end of normal for her clinical signs to be normal.

 

My vet suggested that there is a range of symptoms associated with hypothyroidism, and some dogs will show only one, like Jess with her hair problem, while others may show a combination.

[Lucy Goosey]

Thank you for the feedback, you guys. The tough thing here is that Lucy isn't really showing signs/symptoms as far as I can observe, and everything in the bloodwork falls within normal range. I guess I just have a gut feeling kind of thing going on here. But I'm not the kind of person to medicate where it's not neccessary, so until I get confirmation that there *is* a problem, I think I'll continue to keep an eye on it for now.