guineapig

i have five cats,a guinea pig, snake and two fish..the problem is my guinea pig has like flakey skin on his back and he has hairloss..i have been treating him for about three weeks with neem oil,which a guinea pig owner told me to use..i have bathed him and combed him but although it looks better has not cleared up totally does anyone have any other advice or should i just carry on using the neem oil ???

I would take him to the vet. he could have a skin condition or mites and it's better to be safe than sorry. here's an informative site on guinea pigs.. http://www.guinealynx.com