Growing Teddy will start to go into heat for the first time at 6-8 months old. Most adult Teddy will go into heat 2-3 times a year. However, due to slow development and other physical factors, some female cats will go into heat during the period. She only went into heat for the first time when she was half a year old. Adult female dogs go into estrus once every 6 to 8 months on average, and the number of times a dog goes into estrus per year will decrease with age.