A pound of fat contains roughly 3,500 calories, so a 500-calorie-a-day deficit will cause you to lose about 1 pound each week. You can achieve this by eating 250 fewer calories than usual -- provided your weight is steady on your current diet -- while burning about 250 extra calories per day with cardio.
The heat cycle of the female dog has three parts and lasts about 3 weeks. The first part lasts anywhere from 3-14 days during which a bloody discharge and swelling of the vaginal area are usually seen. Next the dog will become receptive to being bred and actively may seek out a male dog.
In most cases, your dog's body shouldn't go into heat for a few months after pregnancy, but individuals can have irregular cycles. The fact is, how long after pregnancy a dog has her next period, or goes into estrus or heat, varies widely. Most female dogs experience a first heat cycle at the age of 6 months. Unless spayed or pregnant, they'll go into heat every six months for the rest of their lives.