[cypher]

He really is a good age now so it is most probably due to age that you’re seeing weight loss & fur loss.
What are you feeding him? They often need supplementing with soft foods even if they are eating some of their normal mix, so things like ham safe baby food, porridge, tofu & pellets like science selective softened in water, it’s important to keep a check on teeth more so when they are as they can get painful or overgrown & that can cause weight loss, same goes if they eat mostly soft food when they’re old their teeth can overgrow but the main thing at this age is to try fo find what they can eat & enjoy & give them that.
I think some weight loss is inevitable but he may do better with additional foods.
Getting bitey is usually a sign somethings wrong but it is hard to know what so as you’ve had him checked by the vet already I would concentrate on supplementing his diet.