not enough vitamins etc in dog biscuits, they should be fed the proper ferret biscuits as they cant digest them properly, give mine a egg yolk once a week mixed in with lacotose free milk, they love it, never give them the whites off a egg, pigeon breast and leg, mince, ox kidney, pheasant, rabbit, cheap stewing steak and you wont go far wrong, look on freecycle for a hutch, if youve got one in your area, its where people give stuff away, hope this helps you in your adventure, contact me anytime for any info, atb mate