In the past we weight her once every 1 or 2 weeks, because each time she was a little bigger so we did not worry much about weight.
Since she eats less we weight her at least once every 2 days, we do this in the evening when she goes out of the cage.
The problem is that when we try to weight her she always moves , so it is difficult to obtain valid numbers.
I am only sure of the weight of last 2 days because she didn't move during 4 or 5 seconds.
Temperature Inside the room was always between 17°C-22°C in the last 2 weeks
I think there is a real issue but I don't know what it could be.
We have looked at his incisor teeth and everything seems OK (color and length).
The main problems are very small drops and very little hay/pellets eating (she eats the dandelion, but I can't feed her only with this since this would not be adapted).
Concerning food change, Yes in the past we have tried several different hay packs for rodents (supposed to be adapted for chinchillas ...) because she has always sorted hay and eat only what she likes the most.
One week ago to try to restore appetite, we changed the hay and buyed on internet oxbow timothy hay : it worked ... only for 3 or 4 days ...
Now we are back to initial state