Editing Birth (section)

===Dogs===
{{Further|Canine reproduction#Gestation and litters}}
Birth is termed whelping in dogs.<ref name=":0">{{Cite journal|last=Kustritz, M.|year=2005|title=Reproductive behaviour of small animals|url=https://www.scribd.com/document/263302746/Conducta-Reproductiva-en-Pequenos-Animales|journal=Theriogenology|volume=64|issue=3|pages=734–746|doi=10.1016/j.theriogenology.2005.05.022|pmid=15946732|access-date=2016-11-18|archive-date=2016-11-18|archive-url=https://web.archive.org/web/20161118041254/https://www.scribd.com/document/263302746/Conducta-Reproductiva-en-Pequenos-Animales|url-status=live}}</ref> Among [[dog]]s, as whelping approaches, contractions become more frequent. Labour in the bitch can be divided into 3 stages. The first stage is when the cervix dilates, causing discomfort and restlessness in the dog. Common signs of this stage are panting, fasting, and/or vomiting. This may last up to 12 hours.<ref name=":0" /> Stage two is the passage of the offspring.<ref name=":0" /> The [[amniotic sac]] looking like a glistening grey balloon, with a puppy inside, is propelled through the [[vulva]].  After further contractions, the sac is expelled and the bitch breaks the membranes, releasing clear fluid and exposing the puppy. The mother chews at the umbilical cord and licks the puppy vigorously, which stimulates it to breathe. If the puppy has not taken its first breath within about six minutes, it is likely to die. Further puppies follow in a similar way one by one usually with less straining than the first usually at 15-60-minute intervals. If a pup has not been passed in 2 hours a veterinarian should be contacted.<ref name=":0" /> Stage three is the passing of the placentas. This often occurs in conjunction with stage two with the passing of each offspring.<ref name=":0" /> The mother will then usually eat the afterbirth.<ref name=petmd>{{cite web |url=http://www.petmd.com/dog/puppycenter/health/evr_dg_whelping_new_puppies_on_the_way |title=Whelping: New Puppies On The Way! |author=Dunn, T.J. |work=Puppy Center |publisher=Pet MD |access-date=2013-08-28 |archive-date=2018-08-24 |archive-url=https://web.archive.org/web/20180824034316/https://www.petmd.com/dog/puppycenter/health/evr_dg_whelping_new_puppies_on_the_way |url-status=live }}</ref> This is an adaption to keep the den clean and prevent its detection by predators.<ref name=":0" />