I have a female that is dew to deliver in 4 to 5 days time and she is eating her own shit ......WHY IS THIS ???

I gave her right through her pregnancy vitamine and calsuim tablets every second day, the vitamin tablets is a fully balenced tablet for pregnant woman and is expensive.

I always use this tablet and my pups and bitch are always looking good, strong and healthy.

PLEASE TELL ME IF YOU KNOW OF ANY POSSIBLE RESON FOR THIS BEHAVOIR.

THANKS