Hey there girl-friend
I am so sorry, but glad you found out that it is something highly treatable . . . call your vet right away as far as him not acting better, better safe than sorry. . . *****I'm on a high dose of Armour for my Thyroid but am realizing as my dosages go up & symptoms come back that I am also dealing with my adrenals which can cause thyroid problems, as far as people go, you need iodine & vitamin D, either low will cause problems and coconut oil helps a lot of people with thyroid problems . . . (I was way low in D, and hormones) the normal doctor prescribed synthetics like synthroid and levothyroxine do not work for me . . . basically they are giving your body T4 to convert to T3, if your body has trouble converting, those are not going to work, adding T3 or going with a natural pig thyroid like Armour which has more T3 than human seems to work better for me . . . ***** Sorry to throw all this stuff at you but I have been fighting this for almost 20 years and just want you to know that there might be other options & reasons for problems, if something seems to not work, keep digging . . . so many things affect each other: pituitary, adrenals, thyroid, hormones . . . sugars, grains, carbs, caffeine, nicotine, stress, all bad, certain fresh vegies can deplete your iodine, brussel sprouts, broccoli, cauliflower . . . if things don't seem to be straightening up, facebook message me & we will dig . . . often animal medications follow people but seem to be years behind, if it's not working for Bowz we will look for something/someone updated . . . ***** our Quarter Horse mare sierra was hypo, her meds were a few dollars a month, the test was about $40, meds were like $30 and lasted 6 months, she got better and after a couple years was able to go off the meds and never did get that heavy again . . . good luck, hang in there & BIG hugs!!!! Jo