So, not much of any information out there about it. Most of what I've read "scientifically" wise states that it's otherwise "rare", but from what I've read in anecdotal recently it appears it may be far more common than previously thought by researchers, probably because they have not be given a reason to research it that thoroughly. What we know: I first found mention of it in the last chapter of the book "How to behave so your dog behaves, Sophia Yin", where she mentions briefly that some forms over aggressive behavior in female dogs could be caused by being sandwiched in utero between two males transferring to much testosterone to the bitch puppy, the study mentioned was conducted on lab rats. In another book "How to breed dogs, second edition, Howell book house publishing" I read where they conducted studies by injecting new born bitches with excess testosterone till they were several months old, in effect causing them to become not just behaviorally more male like, but they also grew male genitalia of up to 4-6 inches in length. So in essence, it seems that there are cases where a bitch can be influenced by too much male hormone, and in some of the symptoms mentioned is a prolonged lapse of time between heat cycles, with minimal interest in males/mating. Now I've always known that there are some breed differences where breeds like sighthounds of very ancient origins and even their modern counterparts will have longer delays than the average dog, although I found one study that cited anything over 10 months between is "abnormal". You still with me? Probably not, sorry I have an addiction to research (this kind in particular). Recent events, in my own house and in reading other dog owners Blogs about their dogs behavior, has gotten me to thinking about the subject of how hormones play a big part in our dogs behavior. It just seems like anymore though I'm hearing stories of people who have what should have grown to be otherwise normal dogs (bitches in particular, is what I'm interested in) grew up to be "monsters" behaviorally. In females I'm noticing where a lot of people mention certain amounts of inappropriate aggression that seems "off", and as I was reading another new-to-my-collection book I just bought it seems the pieces of the puzzle were all coming together. But then this, I found so many answers in a few paragraphs and that's all we seem to know! Being me, it's not enough! But, I lack the "former education" (only so much a prominent book sale conveniently located next to a prominent vet collage can offer) and funding for a formal study. So, in part of my research I have a few question for you all, I figure I have a large enough pool of people here to ask about this topic. #1, Anyone here know anything else in depth about this topic? #2, Let me know if it's okay to link to the PDF document with the most information on this topic if anyone wants it. #3, Anyone here ever owned a bitch who just seemed "abnormally aggressive" with other dogs? Particularly with males? #4, Anyone here ever had a bitch who had aggression issue, that escalated after a spay? #5, Anyone ever have a bitch given a "pediatric spay" (per-maturity, or before 8 months) that just seemed more masculine in behavior? #6, Anyone ever have a bitch who just didn't seem cut out to be a Dam in personality? Did you breed her? How was her Dam? And the puppies if bred? Did she have odd heat cycles (random, many in a few months, only once a year or longer)? #7, What are your views on dog behavior problems in correlation to the food they are eating? Today in particular, with the advances in the use of "hormones" to increase food production by big named companies. #8, Any other comments you would like to add about said dog which you think might be of importance? Yeah, probably absurd to post this topic, but I have an itch that can't be scratched! Someone please come scratch it!