Did a flt. ex CDG-KGL with supplies for the U.N. peacekeeper troops part of the load was chilled meat, it was during push back the towbar broke while waiting for a new bar our co pilot and F/E were noticed to be short of breath almost on the verge of collapse.We hadthe A/c offloaded and had the cargo repacked.The shipper claimed no knowledge of any dry ice and no NOTOC was issued.