Liver support for elderly cat

Our customer asked:

Our 18 years old neutered male cat has been diagnosed with liver failure derived from a blood test taken 3 months ago. The vet prescribed Hepato Support capsules broken to release the powdered contents and sprinkled on the food.
He has benefited from the medicine and is much better - still able to mount a 6 ft. wall with ease! However, recently he has refused his normal food (Whiskas and Royal Canin Hairball treatment, with cooked lambs liver as a special 'treat') and it seems that he now detects his meals are dosed with the medicine.
We are considering a trial on Royal Canin Renal Special (RSF 26) which may well provide the extra support he needs for his failing liver.

Our reply:

Hills L/D diet is good for supporting the liver, I think that is a much better diet to try. There are also a few non-prescription medications which can be used to help the liver. "Protexin Denamarin" and "Zentonil" are good examples. They seem to be taken readily by some cats, but of course others can be extremely fussy!

You should check with your own vet about suitable diets, because feeding the wrong diet could cause more trouble. I would think though that Hills L/D and some Zentonil are very likely to be of benefit, given what you have said.