My nine month old Sheltie pup has just gone into heat for the first time. I have been ill so she has been staying with my Mum who owns her 9 month old half brother. They have the same Father. My Mum didnt notice that my pup had gone into heat and when I saw her tonight I noticed that she was swollen and was in heat. The two dogs were together all day and Im worried sick now that the male got to her. My bitch is very small and I had already decided that I would get her spayed as she is too small for breeding. I now think he definitely got to her today and don't know what the next step is. Can someone please advise. There is no way she could carry through with the pregnancy due to her being so small and her brother being so big. The vet had already advised not to breed her for this exact reason and as they are related it just shouldnt have happened.