c-section versus natural preganancy

Question
I have purchased a 3yrold St Bernard who's only pregnancy was a c-section.Can she become pregnant naturally the next time? And will she have to have a C-section again?My local vet seems to believe that her chances  of becoming pregnant are slim and most likely c-section.She had 3 healthy pups but I don't know the circumstances for the procedure.

Answer
Hi Susan

She can become pregnant naturally but do you mean can she whelp naturally?  Because that is possible, provided she doesn't have a large litter.  The weight of a large litter will cause stress along her incision. After a c-section it's best to wait a year or two to allow the tissue to mend.

I don't understand why would her chances of becoming pregnant would be slim? That makes no sense.