Hi everyone.

I am the owner of an eight to nine year old Siamese cat. He's recently
come back to live with me after a few years of living with my Mother
(long story). Unforutnately she had a problem keeping his weight down
(she had another cat also) and so he got VERY fat. He's a very large
cat anyway, but he shouldn't be this overweight.
Anyway, as soon as he came back to live with me, I took him to the
weight clinic at the vet's. They've put him on 50g per day of Science
Diet MD (he was previously on 100g SD PD), which seems an awfully low
amount, but I've done what the vet asked and am giving him two meals a
day, first thing in the morning (7am-ish) and before I go to bed
(10-30pm-ish).
This morning he went for his food (he didn't beg for it like crazy as
usual) and had difficulty jumping up for it (I feed him on top of the
tumble dryer so he gets a bit of exercise). I didn't think anything of
it as I was rushed, but when I came back home later this morning, he
was laying in an odd spot on the floor. He only just got up a while
ago and was wobbling. At first I thought he had a limp, but I watched
him closely and it was like his back end was unstable and tipping from
one side to the other. I gave him a little food just to see if he
still had his appetite, fortunately he does, but he's depressed. He
slumped down on the bathroom floor looking forlorn, so I carefully
picked him up, not touching his back end, he was in pain as I was
holding him as his back leg was shuddering and he cried. I've brought
him down onto the settee where I can keep a better eye on him.
I've booked him into the vet's this evening (it was the only time they
had). In the meantime I'm gonna bring his litter and water down here
so he doesn't have to go upstairs.

I was just wondering if anyone here had any kinda of idea of what this
might be? Something caused by his weight? Or his diet? The only other
noteable thing is that I've been using "Petal Cleanse" on him as my
husband is allergic, but as it's a natural product, I doubt there's
anything harmful in it.

Thanks in advance for the help,
Naomi