Thanks for the idea, Stilly, but the fluid in Right-Pondian tuna tins is fish oil. Is that what you mean?

Anyhoo, Ptolemy finished off his last night's tea this morning, then pestered me till he got a pouch of standard moggie-meat-in-jelly, which he ate most of straight away (and finished later). Herself thinks he tends to lose his appetite in hot weather, and we've had a cool spell with lot of rain recently.

The next trial change would be to try him with in-gravy moggie meat. (Curiously, Sainsbury's doesn't market any under their "taste the difference" branding.)