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.
Most will not want to mate the 1st day. For some dogs, the female will be ready up to 2 weeks after signs of heat occur. The average time to breed your Shih Tzu dog will be 2 and 16 days after the 1st signs of heat.