Chins Both Losing Weight

Ever since I got my chins, they've been losing weight. Due to the timing of their vet visits, I noticed that they lost a minimum of 30 and a maximum of 55 grams per month. When I first had them they weighed somewhere in the 700 gram range, probably above 720 but under 780. That was in the beginning of November. Then they just kept dropping grams from there. The first month wasn't too bad though, maybe a 10-20 gram drop. At the vet today, one of them weighed 722 grams, and the other weighed...

Chins Both Losing Weight