Every six months on average.
Dogs come into heat every 6 months.
At around 6 months of age.
Every 6 months.
Dogs usually go into heat twice a year, although some individual dogs will go into heat more or less often. Typically, a female will remain in heat for about three weeks, although she will only bleed for the week to a week and a half.
No, spaying eliminates heats and is permanent. A spayed dog will never go on heat again.
Usually once every six months.
Dogs get the heat twice a year.
That is not exactly what happens. See, unlike humans, dogs don't have crushes or anything like that. The female dog goes into heat, and the male dogs smell it and know they are supposed to mate with the girl dog. The boy dog then mates with the girl dog, and usually it is successful and they have puppies.
As a rule, Dogs come in 'HEAT' twice a year. They generally can have puppies after they are 1 year old, and every year after that. One litter a year usually. It is recommended that dogs don't get pregnant the first time they come in Heat.
heat in sheep
No. Dogs don't have periods either. Does ("girl" bunnies) go into heat much differently than dogs do; they don't bleed out the vagina before they are really receptive to mating.
This varies dog-to-dog - average is every six months but it could be more or less often.