Rat on a diet
if its a wire bottom this can exacerbate bumblefoot so you should either remove it or if thats not possible cover it with sticky backplastic, lino or even newspaper
get him off the treats and onto a good diet
http://www.ratsrule.com/diet.html...
and only as much as he will eat in 23 hours
stop the treats and up his veg intake [limit extra fruit as high sugar content] and lean protein like chicken or prawns
make him work for his food get a kabob and hang veg on it, a mini kong for some dried food, a roll around for the same, a veg hanger to pop his veg in hang it just out of reach - make him work stimulate him mentally and physically
get a cat feather wand, guaranteed to chase and pounce and stair running great fun, remove any ladders MAKE him climb between levels
you could also try getting him a same sex friend to play with, thats great stimulation = -)
well done for catching things early, a great example of a good owner
Edit to add: 23/08
a tank is one of the worse things you can keep a rat in any way but especially one that is predisposed to bumblefoot [sorry = -( ]
your rat cannot help but walk through patches of urine that have settled on the floor, which will irritate his feet and also they encourage rats to walk 'flat footed' he also has no opportunity to climb and use his feet as nature intended
i understand he may be frightend of BIG wire cages but something like this
http://www.martinscages.com/products/cag...