How can I encourage my cat to drink?

One of my four cats occasionally suffers from struvite crystals. Once in March of this year and again last week. Each time we've taken him to the vets it cost us over £200. The first time it cost over £300. He now has to eat 'Hills SD' (expensive) to dissolve the crystals. Even though he had an operation last week he is already having difficulty in passing urine. The main problem is he doesn't like drinking. We have tried a cat fountain, fishy water multiple vessels for his water and we infused catnip in his water. He spends lots of time in his cat tray and only does a few drops. Any suggestions would be appreciated.

I mix water right into the wet food.

Start with a Tablespoon and work it up to as much as you can ...

Also can try syringing into his mouth if he is easygoing ...

I am not sure about the drinking issue; it sounds as if you're doing all the right things, but perhaps some other TCS members may be able to help you on that. I would strongly suggest that next time you go to the vet, you ask about Methigel methionine supplement in gel paste or tablet form (hopefully it goes under the same trade name in the UK as here in the us, but if not, methionine is the actual element you need to ask for). This changes the pH levels in the urine to acidify it more, which alleviates the problem of crystals. If you can get this prescribed, you will not have to feed C/D exclusively, but can feed other low-magnesium, low-ash premium cat foods. If you are feeding C/D, he is getting moisture from that; but I do hope someone else has good ideas as to how to encourage him to drink! Good luck, and keep us updated, all right?