Hi
You seem to have checked most things and so far not found a problem. Certainly keep a close eye out for any of the symptoms you listed that aren't present at the moment. If you are still concerned of course take him for a check up. It can't hurt to do that anyway.
Cathy Wickenden BVet Med MRCVS
Barton Lodge Veterinary Centre
1 Midland Road, Hemel Hempstead, Hertfordshire, HP2 5BH
Tel: 01442 216048 24 hours
[
www.bartonlodgevets.co.uk]