Dog are in heat for 4 weeks. 2 weeks in and 2 weeks out. Explanation... They bleed for 2 weeks but for 1 week before and 1 week after they do not bleed. However they can get pregnant throughout the entire time. They are most fertile the third week tho.
From the experience I have gathered observing my dogs at home, I think a dog can maintain its heat period for 7-10 days. It can occur to them twice a year. One can elicit and arouse heat and sexual hormones in them if they are exposed to the male counterparts. Gradually, they come more faster to their heat periods. If the female dogs are not exposed to the male dogs they will also experience heat, but it may take a longer period. To a large extent, the food dogs eat also contribute to certain developments in their body growth.
They are in heat for 3 weeks. One week going into heat, one week in heat, and one week coming out of heat. If not Spayed, keep the females away from the males for 3 weeks. The male will do anything it takes to get to a female in heat, and can smell a female in heat, from 5 miles away. They normally go into heat, every 6 months (twice a year)! Please have both of your females Spayed to avoid pregnancy!
They are in heat for about 4 weeks 2 weeks coming and 2weeks leaving
They way I've seen it work is that female dogs are in heat for three weeks . To wear you can see their privates are bleeding and it also get very swollen. If it does not conceive then it won't be in heat again until another three months. If it does conceive it is within every six month. Which is three months of her pregnancy and delivering her puppies. And the following three months after that she will be in heat again. This is the twice a year that she is in heat.
Dogs are in heat for about 4 weeks.and it comes twice a year.