>he is having difficulty chewing pretty much anything he licks
What do you usually feed?
If it's kibble then you can soak this until its sloppy, like porridge - use warm water or plain chicken stock if you prefer
Alternatively you can boil chicken for hours until you get a rich broth. The longer you cook it, the more the chicken will break down and it will get easier for him to manage (add rice too if you think he needs/likes it - but again boil this thoroughly to break down the starch). Bones are a doddle to remove from boiled chicken. This should last him a while and can be mixed with kibble porridge, as above, to make it go further.
However, if you feed raw pet mince this can be quite sloppy already. Some frozen pet minces are so finely minced it's like mousse and you can add a little water to make it more liquid if you need to.
Poor lad - give him a hug from me :)