Well, I got so worried about Dylan's drinking/weeing at some point that just over a month ago, I got Ian to do another blood and urine test... both came back as perfectly normal!
So by way of elimination, we suspect that Dylan has psychogenic diabetes insipidus which means that he is drinking excessively for mental reasons. So we think that maybe the stress this year (mainly mine that he picked up on) induced the polydipsia/polyuria. As it is, he has been drinking less over the last couple of weeks and isn't in a rush anymore all the time to go to toilet.
I have upped his Aktivait to full dosage and have also given him CSJ Calm Down herbs... I don't know whether either of those helped.
Dylan's thyroid seems fine now and he has definitely more energy again since being on the higher dosage.
