Dogsey

my youngest son is diabetic and have read about this, they are amazing

Indeed amazing. And I know that smell well. My two boys' father was diabetic and had been since he was 8.

Pear drops smell

What smells of Peardrops?

The breath of a diabetic if they are going into ketosis

Yep peardrops sums it up well. Often reminded me of nail polish too.

Yeah acetic acid

I'm assuming then that the dogs can pick it up before it gets obvious to us?

Yes, its a very strange thing really. I so very nearly lost my youngest son at 17 months due to no one recognising what was wrong despite me knowing there was SOMETHING and in the end being treated as an over anxious mother.
When he was admitted (in a coma) one of the nurses said to me she could smell nail varnish remover and asked if he had drank it, and still NO ONE caught on. I could give you the whole story, but it would fill pages, and I have cried more than enough over the poor greyhound in the Supervet programme last night, and now for Loki, and am filling up again thinking of how my baby boy very nearly died.