My chinchilla has been eating all of her food and drinks a lot of water, but has been slowly losing weight over the past couple of months. She is now dangerously skinny. She got to be real moody/pissy over the past couple of months as well, but I figured it was because I was taking her to some of the local schools for show and tell.
Chinchillas are nocturnal, do not like change (such as taking them from place to place), they do not like loud noises, or allot of movement around them, and are susceptible to many viruses and germs that people walk around with on a daily basis. Good chance your chin caught something from one of the people or the environment you were taking it into and/or you have stressed it out and it has become ill from being stressed.
Today, when I went to get her she was unable to walk in a straight line and was falling to the left over and over. She has a place on her nose where it looks like a blood blister that popped. Her lip was stuck to her teeth because of the blood, but I was able to unstick them and clean it without any further damage. She did not have that yesterday and her cage is safe and I can't find any place that she may have injured herself at. She is weak and her hair is falling out worse than it ever has been. She is still eating and drinking everything.
Is is the shape of it's spine showing? If so, it is probably dehydrated, among other things. Dehydration needs fluid injections.
Your chin is in desperate need of a qualified exotic pet vet that knows something about chinchillas, or will take the time to learn. There are forums on-line especially for veterinarians to exchange medical information.
We're not vets here, only breeders and owners of chinchillas ... many of us with long years of experience ... but that does not mean we can tell you what is wrong with your chin, only what
could possibly be wrong, with the limited information being received and not being able to see or touch your chin we are only able to give you our thoughts on the subject.
Can you post some pictures of your chinchilla for us? One when she was healthy and one recent one.
What brand chinchilla food are you giving her?
Do you have any other chins?
If you have other chins, are they in the same cage or room with this one?
Jo Ann