I'll try to make this short. This is my first litter from this breeding group and they are what I call fancy mice. My other breeding group are white mice. Both groups are kept in the same conditions. The white mice were started earlier and have had about three litters all healthy. The fancy mice are one tan and white male, one grey and white female, and one sandy colored female. The litter belongs to the grey and white female, and they are due to be weaned this weekend.
I have noticed that in this litter, which is a mixture of different colores including one white mouse that all of the mice that are black and white seem to be under developed. And in the last week two of them which were very small died.
Could this be some type of genetic issue? If so, do you think it could be something that is passed on by the mother or the father or both?
Thanks in advance for your help.