yes, it will be a prob. Based on exp, its best to remove fur

The intensity of the registered signal will be significantly reduced by both fur and skin. It means, that even if you remove fur carefully you will have reduction of signal by skin (white skin is a little bit better for light penetration than black one). Please, also take into account, that even small rest of the fur in the field of view will bring admixture in the image like small cloud and each wound (cut) will be a source of bright fluorescence as if you take out the skin in this place. So, the level of the registered signal from the same s.c. placed fluorescent sample will reduced along the line: mice without skin (for example, autopsy), hairless mice, mice with white fur after shaving, mice with black fur after shaving, mice with white fur, mice with black fur.

you have to...