I honestly would never ever breed on the first heat and they start coming in heat around 8 month and stay in for 3 weeks. Then its every 6months on mostly all dogs on a heat range. But the reason I say wait till the second heat is so that she is fully developed. Then if you plan to have puppies have every other heat don't have back to back because they will bring her down and is not healthy for them. Hope I was helpful ask me more if need be I work at a vet
