The condition is pretty common in dogs after giving birth. My Chihuahua had the same problem.The fluid in her case was at first yellowish and it later became greenish. My vet said that the condition is called "mastititis". He recommended Bamitol, a balm made by Bayer labs. I don't know if you can find it where you live, but you can should consult your vet and he'll prescribe something. Goodluck!