I didn’t mention that a couple weeks ago, we heard back from Hemopet, Dr. Jean Dodd’s veterinary institution and lab. I sent everything out on a Monday afternoon. We’re in the same state, so it didn’t take long for the sample to get there. I had results e-mailed to my inbox on Thursday.
Here are Bowdu’s numbers:
T4: 0.87 (reference range 0.80 ~ 3.80 μg/dL)
Free T4: 0.53 (reference range 0.55 ~ 2.32 ng/dL)
T3: < 10, verified by repeat analysis (reference range 30 ~ 70 ng/dL)
Free T3: 1.9 (reference range 1.6 ~ 3.5 pg/mL)
Thyroglobulin Antibodies: <1% (reference range: negative [?])
TGAA CONFIRMATORY TEST INTERPRETATION
less than 10% = NEGATIVE 10 ~ 25% EQUIVOCAL greater than 25% = POSITIVE
Elevated TGAA levels confirm autoimmune thyroiditis. False positive results can occur if the dog has been vaccinated for rabies within 30 to 40 days. Thyroid hormone supplementation can decrease TGAA levels. Performed using the Non-Specific Binding (NSB) Method. 8/26/10
Dear [name of my vet]: Thyroid levels are too low here, and support the clinical issues. The very low T3 reflects concurrent non-thyroidal issue(s). Jean
Adult optimal levels:
T4: 1.40 ~ 3.50 μg/dL
FT4: 0.85 ~ 2.30 ng/dL
T3: 35 ~ 70 ng/dL
FT3: 1.6 ~ 3.5 pg/mL
X Thyroid levels are below minimal expectations for a healthy performing adult
X Thyroid levels are too low. Recommended 6 ~ 8 weeks of Soloxine (R) or equivalent product at 0.1 mg per 12 – 15 lbs twice daily (e.g. 0.2 mg BID), followed by retesting thyroid profile 4 – 6 hours post-pill to monitor response levels. Dose at optimum weight.
X Optimal therapeutic response should be in the upper 1/3rd to 25% above the upper limits of the resting optimal ranges at 4-6 hours post-BID thyroid medication.
To ensure proper absorption, thyroxine is best given by mouth, at least 1 hour before or 3 hours after a meal.
So there we have it. Nothing here came as a real surprise, except for the last bit about timing the thyroid supplements. I had specifically asked the vet if timing around meals mattered for this medication, and they said it didn’t. As I soon learned, thyroxine binds to calcium and soy, so slipping the drug in with food or treats impairs its absorption. Apparently, this is something that human physicians tell their patients all the time, but veterinary clinicians are generally ignorant of this property. Dr. Dodds recommended administering the drug with a tiny marshmallow, smooth peanut butter, or other soy and calcium-free snacks, like some kinds of German sausage.
I was initially disappointed by the brevity of the analysis, as I thought I would get more breed-specific information about hypothyroidism. So I e-mailed back with specific questions late on a Saturday night. The prompt response satisfied me in the end. Dr. Dodds wrote back on a Sunday, which I was not expecting. Aside from informing me as to why thyroxine is not to be given with meals, she also let me know that Hemopet’s database currently only contains about 100 Shiba Inu, which frankly isn’t enough to give a statistically accurate portrait of the breed as a whole. By contrast, there were at least 300 Shiba Inu in Michigan State University‘s Canine Thyroid Registry through 2005 — but I imagine the motivations for going to either lab are very different. My wild guess is that MSU’s numbers are tipped in favor of healthy dogs who are being registered by conscientious breeders, particularly for a breed like Shiba Inu whom are not typically tested or registered for thyroid health. Hemopet, on the other hand, seems to be a lab where concerned pet owners actively request to have their samples sent, and so may be skewed towards dogs that are strongly suspected to have issues.
In our case, hypothyroidism was never even mentioned as a possibility by my vet. I had to push for the thyroid tests myself. When I first asked for the blood sample to be sent to an “outside” lab, my request was met with considerable resistance. In the end, I was able to have my vet pull an extra vial of blood for me to handle on my own. Given how reluctant they were to deal with Hemopet in the first place, it seems like I would’ve been asking too much to ask them to prepare it for proper shipping — which is what so concerned the FedEx employee whom I first approached about sending out the sample. In her mind, if the sample hadn’t been packaged by a “professional,” I was sending out some kind of rogue specimen that must contain all sorts of unspeakable ills. Oh heavens!
The USPS clerk, on the other hand, was much more lenient. He did ask if I had anything “fragile, liquid, perishable, or potentially hazardous.” I couldn’t flat-out lie, so I started to go into detail about how I wrapped the vial in swathes of absorbent paper towel and how that bundle was slipped into a plastic bag, which was then placed in a padded envelope, which was then boxed up. The clerk was overwhelmed by my details, and interrupted to confirm that the item was not hazardous before he slapped the postage on my priority mail box and sent it on its way. I’ve heard that other USPS clerks have refused to mail out bio-specimens, or at least gave others a hard time, so I guess it’s luck of the draw.
So here we are, weeks later, still nursing him along. As of Aug. 30th, we’ve switched Bowdu to Orijen Six Fish in the morning and Primal Raw in the evening, with various supplements in both meals. This is mainly for the sake of convenience now that school has resumed, but I don’t think food is really our focal problem anymore. If we can continue to give him a good diet to boost his skin barrier functions, all the better. Hence, lots of Omega-3s in the form of fishy fish (which is probably his favorite meat anyway) and Omega-6s as well. Unfortunately, I guess hypothyroid dogs experience a thinning of the epidermis (visible on a microscopic level) and slow healing of lesions. So even though he’s on thyroid supplements, those scabs on his paws persist.