From Magda Omansky, Dignpop Norwich I have two comments about the relationship between early whelp and the breathing problems later in life. First, it is really important to understand the definition of an early whelp. It is a scientifically proven fact, not an opinion, that the due date has nothing to do with a breeding date. The due date is strictly related to ovulation. Only when the exact ovulation time has been pinpointed (progesterone tests are the most reliable method) the precise whelping date can be established, which is 9 weeks from ovulation date (63 days from ovulation, not mating). Sperm not manipulated by freezing or chilling lives on an average 7 days, and the eggs need to mature for 2 days after ovulation, so mating time gives an error factor of many days. Scientists have been able to film canine sperm "parking" itself on uterine walls waiting for mature eggs for a week or even longer. To add to that factor, most bitches start flagging and accepting male at the time of luteinizing hormone surge, which occurs about 4 days prior to eggs being fully mature. Some bitches do it even earlier. LH surge is followed about 2 days later by ovulation but the eggs do not mature for another 2 days and they live about 48 hours after that. I know for a fact that one of my bitches had LH surge 3 days prior to ovulation, so the 2 days time-frame of ovulation following LH surge is just an estimate, otherwise all theriogenology specialists will be advocating LH surge prediction. Instead, they ask us to pinpoint ovulation date. I have a litter right now bred 4 days post ovulation (due to all kinds of mishaps). If I calculated the due date from the mating the pups would have appeared to be 4 days early. They were not! They were born precisely 63 days post ovulation but 59 days post- mating. This is my long answer to say that the relationship between breathing problems and early whelp can be investigated only with proper definition of what is an early whelp. That is the first problem I see with jumping on the band wagon of linking respiratory problems with early whelp. It cannot be based on anecdotal and often incorrect reports. My second thought is to make a distinction between UAS (a cluster of interrelated physical abnormalities of the UPPER airways) and under-developed lungs in early-whelp (true early whelp) that matured with hypoplastic bronchioles and alveolar sacks. The respiratory problems stemming from being born too early are related to LOWER airways, not the UPPER airways in all medical literature. Being born too early has nothing to do with elongated soft palate, or everted laryngeal saccules, or stenotic posterior nares, or enlarged tonsils- all the things we see in UAS. Please, please learn to understand UAS. It has nothing to do with lung function. I know, we all would love to find one reason and call it a day. But everything we know about UAS shows a complicated set of anatomic abnormalities, most likely a very broad set of genes, possibly with some environmental triggers but I very much doubt that early whelp, even accurately calculated, is one of them. There is no scientific basis for thinking that.