I have had a nightmare of a time trying to find a saddle to fit my Sec D mare. But there is now a saddle on the saddles page on here (typical now ive found one). It is an Ideal Highland and Cob (H&C) and they are designed exactly for the shape of these horses. It may have already gone but always worth a try.

Pauline,
You might like to consider using a Limpet Saddle Pad - they are designed to stop saddles slipping. You can view more on www.limpetsaddlepad.co.uk

Hi yes definitely take a look at the highland and cob ideal saddle. Got one for our extremely wide section C and it fits a treat. Before we bought her seven years ago she had a badly fitting saddle and quite understandably shows her upset whenever we try a saddle that causes her a problem. The only saddle which she was happy in was a circle Y western saddle. In January my daughter decided to show her in some English ridden classes and for that reason purchased the ideal saddle. It is a super fit and the only we tried which we would even consider, nothing else even treeless saddles stood a chance of fitting her flat wide shape.