Sometimes it's normal for a new found friend not to be very hungry for a few days. But if it continues seek your vets attenion after the second or third day of not eating. When ever I adopt
a new friend I usually make a vet appointment and have my new buddy get an exam to make sure he is feeling okay and there
are no hidden problems. Good luck with your new friend!
Also watch his stool for a few days to make sure it's okay!
and any other symptom that might seem odd, like drinking a lot
of water, not drinking any water, sneezing coughing. Just to
make sure he is not coming down with something else.