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.
Dog Pregnancy Cycle. A dog pregnancy cycle lasts about nine weeks or a little over two months. The due date is determined by calculating the number of days from the day the dog mated and delivery can occur anywhere between the 58th and the 64th day.og Pregnancy Cycle. A dog pregnancy cycle lasts about nine weeks or a little over two months. The due date is determined by calculating the number of days from the day the dog mated and delivery can occur anywhere between the 58th and the 64th day.