Female and Pregnancy Supplement Dr. Harvey’s Fem has been used to enhance the female reproductive system in female cats. This powdered formula can be used in food daily for cats that are pregnant or lactating or after giving birth. The herbs used in this formula act as a tonic for the entire female reproductive system. Many breeders have found this formula invaluable in supporting the system of a pregnant or lactating cat We have seen this product help adult female cats get back their strength and stamina, after giving birth to a litter.