Reading recently I came across a few sites that recommended calcium during labor, from what I understand it causes them to contract. I do not know if calsorb is for the same purposes, hopefully someone here knows more and will answer, I'm interested in knowing as well. Heres what I found at a few sites...
Extra calcium is given only after pups are born, and during active labor, to help with contractions for another reason, other than teeth and bone growth of pups. Calcium during the pushing stage of labor will make the muscles contract at that specific moment. At the first sign of a contraction, give her some calcium. Offer her vanilla Ice cream, or chew a tum and spit in her mouth, or use Calsorb. http://www.dogbreedinfo.com/whelping.htm http://www.dogbreedinfo.com/breedingpregnancyguide.htm