Can anyone help?
My dog has taken to constantly sniffing the ground in the ring which is really letting him down and two weeks on the trot now we've taken last in the class because hes not focusing on me and is more interested in walking the ring with his nose on the ground. Judge comment yesterday was "He thinks hes a scent hound" hes a toy breed :/

He is a dog and obviously there are lots of bitch smells but this behaviour has only just started. He is 13 months old.

All advice greatly recieved, our next show is a champ show and I really do think I should pull him out if I cant stop this.

Been there, done that. TBH there is not a lot you can do he will grow out of it, if he is food interested then he may be tempted by that, carry it in the hand that has the lead and try to take your hand from his nose to a position in front of the dog the idea being he will be more interested in your hand than the ground.

Not all judges would penalise your dog for this and matters will be better during the winter and he should have stopped by next year. in the mean time try moving him in the other hand when you can and moving the "wrong" way round the ring - all in the hope you will give him something else to think about.

You can clicker train the head being held up.

> You can clicker train the head being held up.

yes. train the dog to look at you and use sniffing as a reward. I did this with my boy for various things such as Loose lead walking and watching me.
I would keep him on a short lead when we came up to a post or something he wanted to sniff to stop him getting to it and just wait. eventually he would realise he was getting nowhere fast and look at me to see what the problem was whereupon I would click and let him move forward to sniff. once he got the idea I would raise my criteria and ask for attention for longer before I would let him sniff. I am sure it would work in the breed ring.
Train it in other places first so he is familiar with what you want. Start asking him for a show stack before letting him sniff. then in the ring you can ask for a stand until the judge has gone and let him sniff .