Behavior in Mother Cat

Question
I am fostering a mother cat and her 4 kittens that are now 3 days old.  They were born in my house and she was with me 2 weeks before birth.  She is in a room all to herself for privacy.  The birth was tough as she started delivering in the litterbox and refused to clean the first 2 as they were caked in litter.  We moved her from the litterbox onto sheets, cleaned the first two and the second two were born without intervention.  Now she has taken to "burying" the kittens on occassion.  We will find one in the litterbox every now and then and have found one buried underneath sheets and blankets.  She only separates one at a time and not always the same kitten.  I'm concerned that she might be trying to kill them or something.  Should I be concerned and remove them from her care?  Is there some kind of supplement I could give her that would help her relax as she always seems stressed?  Of course the supplement could not hurt the kittens.  Any advice would be appreciated.

Answer
Cindy, this is a new one to me!  I'm wondering if she feels she cannot care for all the kittens.  When a mother consistently rejects the same kitten, it's usually a good indication the kitten is unhealthy.  But with her booting out different kittens, I would imagine it would have to be along the lines of being unable to nurse them all while still remaining healthy herself.

My suggestion would be to get her and the litter to the vet.  See if she's producing enough milk or if maybe the kittens are sick.

In the meantime, I highly recommend to purchase a mail scale and weigh the kittens daily.  Each should gain 1/4 - 1/2 ounce every day.  If they don't gain weight for more than a day, or they EVER lose weight, and vet needs to be consulted.  This is the first sign of Fading Kitten Syndrome, where kittens die for unknown reasons.  Sometimes an antibiotic helps.  You may need to push the vet to give you antibiotics for a kitten this small, but it is often the only thing that will stop kittens from fading.

It is never a bad idea to supplement a kitten with bottle feeding when you're unsure of how the mother is caring for them.  I use KMR powdered formula.  My kittens take that better than the canned version, and better than other brands.

My only real concern with leaving the kittens with her is that if she separates a kitten, it could easily chill and die.  Kittens are unable to regulate their body heat until they are several weeks old, and a chilled kitten does not survive long.  I would see if supplementing the kittens with formula helps take a load off of the mother.  See if she'll care for them all then.  If she's not on kitten food, I would switch to that over a week's time, also.  It's got extra fat and protein she needs to produce adequate nutrition for the kittens.  You can even offer her some kitten formula.

As for relaxing her, you could try some catnip when you catch her going to eat.  It will excite her at first but has a calming effect after about 15 minutes.