Almost back to normal today
He behaved himself very well overnight - ate all his biscuits which I had put away from the den and then settled back down in his den again. Didn't hear from him at all until 5.30am when he wanted proper food (applause).
He's having a snuggly day again today- not letting him out yet. He's almost back to normal.
Hoping that the weight loss is just the summer thing and stopping free feeding. He does usually look slimmer in summer due to playing out more but this year he didn't put much weight on over winter so he hasn't got as much to lose. He's still a big cat (not fat, just big) so I'll only be worried if he loses more between now and vaccination time.
Thanks guys