My cat is 18 and ever so often he has just has this odd scent... I cant even describe it really... it doesnt smell like pee or poo but kinda musty.....anyways.....some days are worse than others and some days he doesnt smell like anything. He acts the same way hes acted since he was a kitten, so he doenst seem to be sick or anything. So i dunno why he stinks!
Is he an outdoor cat? If so he might be rolling in some yucky smelling flowers.
Lyly, could the odor possibly be from his mouth? It's not at all uncommon for older cats to have dental problems, such as gingivitis or an infected tooth.
If it's not coming from his mouth, it's probably that he doesn't groom himself as well as he used to (as cats age, the barbs on their tongue that they groom themselves with actually wear down.) I suggest fluffing him with a bit of dry cat shampoo if it bothers you; sprinkle a bit on his fur, work it in a bit, then brush it out completely.
If it's not coming from his mouth, it's probably that he doesn't groom himself as well as he used to (as cats age, the barbs on their tongue that they groom themselves with actually wear down.) I suggest fluffing him with a bit of dry cat shampoo if it bothers you; sprinkle a bit on his fur, work it in a bit, then brush it out completely.
Maybe he isn't able to clean himself properly. Or maybe his anal glands are secreting (this happens sometimes). Try to find out where the smell is coming from- is it the mouth, the fur, or the anus? If you think this is a problem go and ask a vet.