Try loosening the noseband/taking flash strap off.
How thick is the current bit? You may want to try something with a port or slightly more shaped to give the tongue more room.
The dentist will be able to tell you if your horse has any sharpe teeth that could be causing this and of your horses mouth conformation, it could be that the bit you have in is pressing on the tongue and the horse is just trying to escape it. If everythings ok it could just be a habit, Peeky a horse I used to know did this, he looked very commical, his tongue used to flap
but everything was fine in his mouth, just a habit.
Could be worth trying a hackamore to see if he does it then?
Yes, you are right to reccomend that people ask the equine dentist but perhaps they just want someone to talk to about the problem before the relevant proffessional comes out.
I used to ride a 14.2hh Welsh D Stallion he was 22 years old and had been putting his tongue out at one side of his eggbutt snaffle bit since he was broken. I do think it can come about through pain, bad riding whether you caused the problem or inherited it with the horse as the horse in question also leaned more on this side of the bit as well. I only rode him for a few months and I would never have cured the problem as he had been doing it for so long.
my mare does this all the time ive tred loads of bits and nosebands to no avail it isnt a problem rideing she isnt resistant but some judges mark her down thinking she is ressiting or has tongue over bit which she never does but it can effect our place at shows and marks at dressage let me know if anyone finds a cure btw my dentist says she has no mouth probs
Did you break the mare in yourself? As I say the 'problem' could be inherited. Its a shame you get marked down but the judges do see it as a resistance. A schooling problem rather than pain related. People think that the contact on the reins cannot be even if the tongue pokes out to one side. But I also believe that it can simply come about because thats the way the horse feels comfortable although this could be related to conformation of the mouth or an anxiety issue. The horse simply believing there is not enough room in its mouth for the bit. Maybe when it was backed the mouthpiece was thicker or simply disliked by the horse and that is how the problem started. I cant imagine how a flash nose band would cure it though, I would have thought this would have annoyed the horse more??
My mare started doing this just over 2 yrs ago when she was 8.
I changed her bit from a french link fulmer snaffle to a kimblewick in case a ported bit made a difference. It didn't make any difference, but when the dentist came he removed a wolf tooth.
She is now 10 and still does it! She has had 2 more visits from the dentist who says nothing is wrong, she has never worn a noseband and is constantly flopping her tongue out of the side of her mouth. Occasionally she gets her tongue over the bit, but not all that often. She does it at walk, trot and canter, and when she's being ridden and driven. She is back in her french link, and if anyone has any ideas I would be soooooooo happy to try something new!
i did break her myself and am very experianced and do pride myself on them all have excellent mouths ,but i do think anxiety is the problem with her she was 4 when i got her never handled or even haltered as a foal and it took me 6 months of hard work to get her confident enough to be led by a halyer and handled ect and a further 3 mnths to ride her she is very well schoold and i love her but she is and always will be very nervous and i do think she sticks her tongue out through worry so i dont think i will cure it ,we still do very well and we have won many championships at shows but it is putting me off the dressage ,believe me i have tried alsorts but will try anything new if not cruel of course