It' s a thing I've noticed a while now, and although it requires visible checks pre race, seems to work more often than not Whilst parading look out for curled Tailed Dogs, not just a curve but like a coiled spring, very much on their toes, back em blind to level stakes, had three win today, didn' bother with those that didn' mmeet the curly tail rule, it does rely on you watching pre parade dogs, but I believe a good system.
And then there's the old "Back the horse that's just had a massive turd" theory. Personally, I don't think horses have the same sense of relief some humans feel after a desperate and frightening fight, squeezing one out. The dumping theory is just a load of old horse ****.