horses that have bad wind and whistle

[x_lou_x]

ive just taken over the ride of a super horse but she whistles despite having two operations to correct this... not sure what vet has said about this but owner recons everything is fine despite the obvious noise she makes! so i have a few questions ....

1) will she ever pass 5stage vetting?
2) will it affect her performance? (shes a showjumper)

thanku in advance