Amidst the possible causes indicated herein, it is categorized either as disease and non-disease conditions.
Allow us to cite some common causes (disease and non disease)of fur loss on the belly which may include urine scald, constant rubbing of the exercise wheel, bedding allergies, fungal/bacterial medical skin problems, natural fur shedding process (moulting) or dietary deficiency issues. We suggest to check these possible causes and have an appropriate steps to address them.
If signs persist, refer immediately to your veterinarian.
With best regards,
Eliezer M. Bauzon, DVM RN