Leigh, great links, it also ties in nicely with the teleseminar that Inge posted about, it's free via internet online or you can use the telephone as a USA phone call.
http://www.dressagedisgrace.com/live-te ... -hempfling
Hope they explain bitting as well:
http://epona.tv/uk/news/show/artikel/bl ... ?tx_ttnews[backPid]=388&cHash=563648c137
Quote:
Blue tongue due to ischaemia
"When we see dressage horses with blue tongues, it's because blood circulation is reduced in the tongue. When the blood supply is reduced, tissue hypoxia ensues in the tongue, and it turns blue," says Marianne Dahl, DVM, a Danish equine welfare specialist. She elaborates:
"The explanation is in the horse's mouth and it's the curb bit and rein tension which cause the problem. As long as a horse is not bitted, the tongue is relaxed and takes up the entire oral cavity. The tongue is a very dextrous and sensitive organ. In a well fitted curb, the tongue can still be relaxed and fill out the oral cavity as long as there is no rein tension. The moment the rider puts tension into the reins, the angle of the curb to the mouth is altered, and pressure on the tongue is increased. The tongue, which consists of muscle tissue, becomes tense and may be flattened."
"If the tension is high - which is to say that there is a marked change in the angle between the shank of the bit and the bars of the horse's mouth - and if the pressure is held for a prolonged period, ischaemia and hypoxia may follow. The tongue will become discoloured and turn blue or purple. If the chain on the curb is tight, the pressure on the tongue will be stronger, and if the nose band is tight, so the horse can't open its mouth, the pressure on the tongue will be even stronger still."
I think this video is helpful in explaining to those still impressed by the dressage diva's, how hyperflexion damages the horse and why you should not attempt to emulate this style with your own beloved horses.
http://www.youtube.com/watch?v=O0hyOmMULYA