Estrus is the stage of the reproductive cycle in which the dog can become pregnant; sometimes a dog that is in estrus is said to be in heat or in season. On average, puberty or sexual maturity is reached at about 6 months of age, but this can vary by breed.
A small scale enterprise is a privately owned and operated business, characterized by a small number of employees and low turnover. A small enterprise usually only shares a tiny segment of the market it operates in.
There is no concrete definition of what constitutes a small business. In fact, my company targets small to midsize companies, and I construe that to mean those with up to 250 employees!