He's gone now, Catherine. It's very sad.

I've just acted on the increasingly stiff hind legs I've noticed in Tahi
over the past few weeks. At 10? I thought it might be early-onset arthritis.
But it appears he has patellar luxation, otherwise known as dislocating
kneecaps. Apparently extremely common in dogs, not so common in cats. But,
interestingly, it has been mentioned to me that Tahi has an Abyssinian body
shape and is probably part Aby, and a google search suggests the cats that
are most prone to this condition are Devon Rexes and Abys.

So, after the drama of getting him to the vet yesterday, I now have to
repeat the mutual torture for the next three weeks so he can have injections
of pentarthron, which should help to rebuild his cartilage and avoid the
need for surgery. Tahi will make me feel like the meanest Mum in the world
every time, but I'll grit my teeth and bear it. Otherwise, it's double knee
surgery, which both Tahi and I are hoping to avoid!!

Interestingly, at least here, said drug is actually only licensed for dogs
because this is so uncommon in cats. Vet assures me that it has worked very
well on the cats he has used it on.