Dog fear periods, often called "critical periods", can confuse new dog owners. If your happy, bouncy puppy suddenly becomes fearful and nervous without an apparent cause, it could be a dog fear period. Though the change in behavior doesn't last long, it takes careful management during this time to prevent future fear-based behavioral problems.
According to The National Library Of Medicine, the concept of dog fear periods began in 1945 when two scientists, Scott and Fuller, launched The Dog School to explore critical development periods in dogs.
