My special little boy is 9, we moved house a few months ago and he was diagnosed with hyperthyroidism a few weeks later, along with some kidney function concerns and a heart murmur. He was put on thyronorm and seemed ok, still skinny but perky enough. A few weeks later, so a week ago now, he suddenly got very dehydrated and was taken in overnight on a drip. The next day he seemed better, was eating and drinking. Then on Tuesday he suddenly disappeared to a warm cosy spot all day, and when I saw him his third eyelid had prolapsed and he stopped eating/drinking again. I'm not keen to put him through invasive tests, as he's been through so much, but 2 days of antibiotics and painkillers hasn't helped his eye much. The vet thought it's possible there's a tumour behind his eye but it's hard to identify without an ultrasound. He's eating a bit but mostly sleeping all day, and has had watery diarrhoea. I'm taking him back to the vet tomorrow, but I'm so torn. Should I try giving him more time to recover? Or have the ultrasound? Or is it time to let him go?