ANY and ALL saddles even when fitted correctly will NOT fit your horse at all times, a horse changes shape depending on condition, hardfeed , time of year , avialiability of forage ( grass & hay ) and of course not forgetting the horses age and health ( just ask MIE how Nelson chaged shape when he had 3 months off from competing due to injury ) .
Try to learn the basics of check-fitting a saddle - if you are unsure then ask someone like Luvs2ride ( a saddle fitter by trade ) for advice - a basic check can be done via the internet using photos but please be aware that this is not guaranteed and does take up a saddle fitters time some $$$ would be appreciated ( NOT asking for myself , but I wouldn't want Luvs tied up all day looking at pics of saddles on horses and not able to earn a living )
Many trainers , who might be great with either horses or people , don't fit saddles and don't really know themselves are trusted 100% because they are a persons trainer - I know of cases where trainers have told people that their current saddle dosen't fit , but they just happen to have one for sale that does , not to tar all trainers with the same brush but be aware there are some bad apples in all trades.
A saddles flocking will also need to be adjusted during the course of a year and replaced depending on how often the saddle is used - this is really important and will keep your saddle and flocking in good order.
Not to be PC but for those riders who tip the scales a bit , a good saddle fit at all times really important - one purpose of a saddle is to distribute a riders weight over the largest area possible and a saddle that is a poor fit or is in poor condition can wreck a horses back put a rider in a bad position and remove some of the pleasure from riding for both horse and rider
As I said before - try to learn the basics of check-fitting a saddle and check your own saddle to your own horse yourself at least once a month - a problem spotted early will save both you and your horse a lot of pain - both physically and financially.
Sorry for the book , but all too often I've heard people tell me that their saddle must fit because it was originally fitted by a pro - I ask them WHEN it was fitted - Oh, about 2 years ago !