In medicine, etiology refers to the many factors coming together to cause an illness. It is normally the focus of epidemiological studies. The etiology of scurvy is a good example. With scurvy, sailors going to sea often lacked fresh vegetables.
So, how long are dogs pregnant? The answer varies depending on several factors, but the average length of gestation, aka pregnancy, lasts between 58 to 67 days, with 63 days being the average delivery date.
How Long is a Dog's Pregnancy? Pregnancy in dogs typically lasts 63 days (about nine weeks). The duration of a dog's pregnancy can fall in the range of 58 to 68 days. Though estrus (heat cycles) can vary from breed to breed, the normal gestation period falls within the same range for all dogs, regardless of breed.