I used it once about ten years ago. Bred a daughter of Vietnam's Ch Spike to Gr. Ch. Sparky. Once naturally and once with the PG600 neither time took but I just chalked it up to Sparky's low sperm count, but I've heard many use it without any problems or issues arising from it's use. Personally, I'd just wait if she is young and if not I'd get her checked out by a vet to make sure everything is kosher with the bitch...