Sorry to hear about Mutty's recent diagnosis
First of all how old is he and is he in good health otherwise? There are options other than daily medication - one of our members recently had the iodine treatment for their cat and it seems to have been a great success. There is also the possibility of the operation and I believe nowadays there is a food which is designed to help control it, Hills YD.
There is also another type of medication which the vet can prescribe if Mutty doesn't seem to be improving on the Vidalta, although the alternative is usually twice daily so not ideal if you're struggling with tablet taking.
My cat was diagnosed hyperthyroid when she was about 14, in hindsight I wish I'd gone for the operation but I didn't know then what I know now and thought 14 was very old in cat terms so was worried about an operation. She lived til she was nearly 19 so had five good years after diagnosis as the medication (felimazole) did it's job. It's a balancing act getting the levels right so she had regular blood tests but she got there in the end.
I think with the operation and iodine treatment it's important to get his levels stabilised before considering them so here's my top tips for getting the medication inside them!
I feel suitably qualified to advise on this Tiggy had over 2000 tablets over the last few years of her life and the methods below were successfull 99.9% of the time... however Lu & Riley are two bright young things and they had other ideas so I had to revise my methods when they had antibiotics last week and came up with the Webbox trick as well!
The tablets the boys had were very bitter and had been broken into pieces so the bitter insides were exposed hence some of the methods were rumbled by them.
1) Webbox treats - a soft malleable stick treat - cut a small piece off, cut that in half and then mould the treat round the tablet. 100% success rate with Riley, available in Tesco/Asda etc
2) De-furrum treats - break in half and poke the tablet in the gooey centre. Available from Pets at Home, Jollyes
3) Dairylea/Primula - poke tablet in blob of aforementioned cheese.
4) Wafer thin turkey ham (Bernard Matthews) - hide tablet inside mini parcel.
There are others on here who have much more recent experience with hyperthyroid and hopefully they'll be along shortly