Canine Thyroid Replacement Therapy: Cookie Is Hypothyroid—Treatment Response Re-Check

So it’s been a bit over six weeks since we started Cookie’s therapy after she was diagnosed with hypothyroidism.

The recommended timeline to check whether the prescribed dose is optimal is six to eight weeks after starting.

It is a good idea to avoid any discrepancies with potential results variations between different labs. Therefore we decided to retest with Hemopet, where we did the initial testing. I was actually surprised how problem-free the adventure was—shipping a blood sample over the border.

We had our share of challenges trying to ship a tick for Lyme testing. You’d think that shipping a dead tick, submerged in a vial of alcohol and carefully sealed and protected shouldn’t be a big deal. Trying to get Jasmine’s adipose cells to Vet-Stem and processed stem cells over to here was quite a quest too. Kudos to FedEx which seems to be the only provider able and willing to deliver such weird things.

Shipping Cookie’s blood to the Hemopet lab was quick and smooth. As well as the test results have come back and a lightning speed each time. You get results emailed to you the next business day from the time they received it.

Timing of the blood draw is important.

In dogs, thyroxine has a half-life of about 12 hours. To get usable test results, it is ideal to draw the blood four to six hours after administration of the meds. Being aware of that, I made sure I could get the appointment at the right time. Doing it too early or doing it too late would not provide usable information about the accuracy of the dose.

I had some questions about whether Cookie’s prescribed dose wasn’t too high.

Based on the retest results, it is a good dose for Cookie after all. The levels are kind of “highish” but we also tested 4 hours post-administration. They specifically wanted to know the timing to take that into consideration when evaluating the results.

Either way, it was their conclusion that this dose is good for Cookie. I went with them specifically because they are the experts on the thyroid.

The interesting thing of note is the remark regarding the T4/Free T4 ratio. Below a certain range, this would mean that there is something else going on with Cookie’s health. Either not related to thyroid at all, or thyroid issues plus something else along with it.

There are many things that can mess with the thyroid hormone levels which have nothing to do with the thyroid function. For example, when Cookie had pancreatitis, her T4 levels tanked.

There doesn’t seem to be anything else wrong with Cookie, nor is anything showing on her other labs. Everything looked good.

Are there visible changes in Cookie since we started the treatment?

There was some quick overall weight loss right away. The weight didn’t seem to have dropped further (as much as one can trust the scale). I am, however, seeing changes in the way Cookie’s body looks– better-defined waist, etc. So we’ll see how that goes.

Her tolerance to cold seems to have increased. One of the reasons I was suspecting poor thyroid function was the fact that her feet would get cold outside during freezing temperatures much faster than they used to.

By freezing temperatures I mean -20 degrees Celsius or less, just so there is no confusion. We already had a few days like that this year and it, again, takes much longer for Cookie’s feet to get cold. Not exactly empirical data but worthy of observation.

Another interesting finding is that she seems to digest her bones better. Before I had to work really hard on offsetting the amount of bone she eats by a sufficient amount of fiber; else her poops would get very dry and hard. It seems that she is now digesting the bone matter much better, needing much less fiber to keep her stools just the right consistency.

The fur on her main seems to be changing back to black color but that could just be from less exposure to the sun since it’s been mostly raining or snowing lately. Who knows. But it is changing so I figured I’d note it here.

Next retest is recommended in one year.

That doesn’t mean I won’t be monitoring how things seem to be working out for Cookie and wouldn’t retest earlier if I had a suspicion something has changed in the status quo. For now, though, we won’t be making any changes.