I have two female shepherds, mother and daughter, and have been breeding them for several years. They have always been like clockwork. One has a heat cycle every 6 months and the other every 8 months. They finally cycled together last year in July and were both bred and had two large litters a few days apart. The older female is six and she lost several pups. I had a necropsy done to rule out canine herpes virus. It was a litter of 16 and was determined they just weren’t getting enough milk even though we were trying to supplement them. She had never had a litter over 12 puppies and I expected the litter size would get smaller with age or I wouldn’t have bred her as many times. The four year old female had a litter of 11 and all survived. However, neither one of the females have come back in heat. It has been 10 months. What worries me is that another Breeder bred her stud to some females from the same kennel where my stud came from and her stud has not been able to produce again either, even though his sperm count is good and looks healthy & strong under the microscope. A negative Brucellosis test was produced on all of the females. I’m looking for suggestions of what else could be causing these dogs to become infertile. I have discussed it with my vet who is not a reproductive specialist, and she is unsure. Before I see a specialist, I was hoping to be able to do some research myself. However other than brucellosis & canine herpes virus which have both been ruled out, I am not finding anything. Has anyone else experienced this before? TIA!!