She doesn't want to mate with him .
She may not want him for some reason. Is she receptive? That could be it or she may just not want him. It happens. Is it a breed that is normally AI'd? That can often have a lot to do with fighting and injury and body type with those breeds like Bulldogs. Some breeds don't usually breed naturally and it's best they aren't allowed to try. If that's your best match and now is time you may have to have the vet inseminate if you are really wanting to have pups. You do not want a fight while they are tied and if there are indications it might be a really bad idea to keep trying and you could end up with no pups and very large vet bills and things.
www.learntobreed.com
www.dogbreedinfo.com
www.marvistavet.com
www.marvistavet.com
www.lowchensaustralia.com
www.bullmastiffsonline.com
www.wildheirlabradorrescue.org
www.dogfoodanalysis.com
www.bornfreeusa.org
www.learntobreed.com
www.dogbreedinfo.com
www.marvistavet.com
www.marvistavet.com
www.lowchensaustralia.com
www.bullmastiffsonline.com
www.wildheirlabradorrescue.org
www.dogfoodanalysis.com
www.bornfreeusa.org