Not sure if this was natural or not, since it is so rare to lose a litter with breeding items on the female, but I bred a female of mine to a male, and put a ptarmigan feather and green fern on her. However, I lost the litter because of no space today. I bred her again today (to the same male) and the text that shows what items are being used on her for the pregnancy showed green fern and ptarmigan feather. Is this because the pups were never generated into the game so the breeding items simply passed onto her next breeding? I was not sure and wanted an official opinion on this.