I have found that this sort of thing happens when a bit of the ovarian
tissue is left after the jill has been spayed.
 
The bit can be so small as not to warrant another operation on your jill,
but if it happens again it would be worth taking her for the jill jab.
 
It might be worth you having a word with your vet about the problem.
 
http://www.smartgroups.com/groups/house-ferrets
http://www.smartgroups.com/groups/head-gardener
http://www.geocities.com/houseferrets13uk/index.html
http://www.webspawner.com/users/ferretwelfare/index.html
http://groups.msn.com/UKHouseFerretsSmallPetsAssociation
 
Artis Pet Sanctuary, Doncaster, Yorkshire ,UK.
[log in to unmask] Registered Charity Number 1069533.
 
http://www.headway.org.uk/
Some great people who have supported me through my illness.
[Posted in FML issue 4293]