A number of non-infectious causes can result in diarrhea. These include lactose intolerance, irritable bowel syndrome, non-celiac gluten sensitivity, celiac disease, inflammatory bowel disease, hyperthyroidism, and a number of medications. In most cases, stool cultures to confirm the exact cause are not required.
Most dogs are first bred between the 10th and 14th day after the onset of proestrus. As long as the bitch will accept the male, mating every other day for a total of two or three matings is generally considered sufficient. However, signs of proestrus are not obvious in some bitches.
Young dogs do not have quality sperm. Almost all dogs will have sperm by one year. Stud dogs are at their prime between 18 months and 4 years old (or 5), after that, the quality of the sperm starts to lessen, and the ability to penetrate eggs, lessens.