Strictures in the vagina

Question
My AKC Ruby female Cavalier King Charles Spaniel started a silent heat about a month earlier than I expected.  She is 2 years old. We have held off breeding her until now.I also have an AKC tri-color male. We realized she was in heat when he mounted her.  She cried, then they tied and everything seemed to go like it was supposed to. We waited 48 hours and let him mount her again and this time she screamed until the tie and then they were fine. We took her to the vet and he said he could feel a stricture. I've only read one article in a breeding book that mentions strictures and recommends spaying the female so as not to propagate this trait. My vet said also if she is pregnant we will have to do a c-section on her.  Could you please tell me more about strictures and our options. First and foremost I don't want to endanger our Ruby or put her through a cruel mating, but she is a beautiful Cavalier and her temperament is such that she would be an excellent mom to puppies.  Thank you for any advice you can give me.

Answer
Vaginal strictures are not uncommon in bitches of all breeds. They can be caused by hormonal imbalances, she might not have been ready to breed when he actually bred her. Usually with strictures it is better to have the bitch evaluated prior to being bred, and progesterone screening done to insure a proper time for a tie.But then any bitch that is possibly going to be bred should have a complete physical and a digital vaginal exam prior to breeding for this among many other reasons,.In some cases a stricture is simply there because the bitch has never been bred and once a tie has been accomplished the stricture is loosened. Very often vets can snip the bands that are causing the stricture with no problem. A good vet can evaluate the bitch and either repair the stricture of advise you of the need for a csection. This has not been proven to be genetic , so I can't say that breeding your bitch is propagating the trait. There are people who believe this to be a genetic issue, however it is one that is easily correctable. If your bitch is nice in every other way and has done well in all of her other genetic testings,. is sound,. ,both in conformation, temperment and health, dont' let this be the one stumbling block that causes you not to breed. However DO have the stricture corrected prior to whelping. If you have not run the gamut of genetic testing and having your bitch evaluated for breeding, then yes I agree she should be spayed. But for many other reasons, not just due to one easily correctable issue.,
Good luck with your pups :)