Sorry Chico I work Saturdays so I can't get on until late as per usual during the week.
Do you have the actual T4 number from the last test & what was it the test before?
What is the dose Rocky is on? How many times a day does he get 1/2 a pill?
As SCM mentioned instead of dropping a 1/2 pill at a time, a slower decrease would be ideal. What would be ideal is to evenly decrease the amount of meds throughout the day from each dose. This way there is still a consistant amount of meds in his system instead of the meds level being up & down all day and "crashing" during lunch when he doesn't get any & making him cranky.
As for missing 1/2 pill does that make a difference? If it was only 1 dose that was skipped probably wouldn't be very noticable at all. But Rocky has essentially "skipped a dose" every day for the last couple of weeks - that will make a difference in the T4 level because the overall amount of meds he got in this past 2 weeks has changed by a fair amount from the amount of meds he got in a 2 week period say 3 months ago.
Give him the 1/2 pill @ lunch time until you can talk to the vet & explain the symptoms that have returned during the weeks his dose was reduced by 1/2 pill. Then your vet can work out whether a slightly lower dose overall during the day would be suitable for Rocky
