It sounds like your piggy is ill. Without more information, I cannot give you any help other than to say you definitly need to the little one to the vet. There are many illnesses and issues that can create these problems. If your pig has a mite infestation, this can create hairloss and weightloss. Mite infections can kill a guinea pig, Mite infestation are extremely, and I mean it...extremely painful to a guinea pig and can even kill a pig. This is my main concern. If your pig is a female, a hormone imbalance can cause hairloss aside from other issues.Please join cavy spirit and guinea lynx, I highly recommend it and strongly encourage it. These sites are 100% devoted to the love and care and raising cavies (guinea pigs). Guinea lynx is an excellent site to join, you can take your medical questions and concerns to the forum for advice and suggestions, overall , take your pig to the vet asap as there can be a serious issue that needs attn. Please take your pig to an experienced vet asap.
good luck and please keep me posted.
not to scare you but a year ago my penny gig did the same thing..it resulted in her death. Please take piggy to the vet so you dont loose her. Mines organs came out of her bum ):
best of luck
how can i tell if my gunia pig is a male or female?
It's a little tricky but not impossible. If it's a full adult, you can feel the testicles in the rear between his legs. If it's a young guinea pig you flip it onto it's back in your hand. With the other hand place one finger on each side of the opening where it urinates. Gently press. A female will just have an opening; a male will have a little penis pop up. It sounds difficult but it's not. It doesn't take a lot of pressure.