My youngster is coming along nicely but I?m a little concerned that any canter work when schooling seems to trigger a lot of sneezing. She doesn?t sneeze in walk and trot and only starts sneezing in canter work. She doesn?t do it when jumping as is focused on the fences. She doesn?t headshake and she has no cough or discharge at all and is in good health. Could this be a habit or an indicator to a possible problem? Has anyone had experience of anything similar?