Sorry.. got hold of the wrong end there, Trigger. I thought Tosker was FIV.
The thing is, Trigger, it's not just a matter of the smell... bad teeth and gums can be horrid for cats. They don't realise what's wrong and often don't notice the gradual deterioration until it gets intense. My biggest wake up call about teeth happened with my Tilly a few years back. Suddenly overnight she began some really strange behaviour... she started walking backwards, was terrified of her surroundings (she behaved like the TV cables were snakes about to eat her) and eventually she refused to walk at all, not even across the kitchen floor to her food bowl.
You'd think all that was a behavioural issue and the first vet prescribed Feliway. Luckily I went for a second opinion and that's when we found a tooth had snapped off exposing the nerve pulp.
With every footstep the pain shot through her jaw. She thought the source of the pain was in front of her - hence the walking backward to try to escape from it. The hypersensitivity and fear of her surroundings was caused by increased adrenaline released by her brain to deal with the pain.
All that was the start of Tilly's teeth issues. Since then she has had all bar 1 canine taken out. She was tested for Calicivirus but was neg. She did prove to have weak teeth and gums though but we never did find the diagnosis as to why. But ever since that first episode I have watched my cats teeth like a hawk.