Last Saturday my family got a 1 month old kitten (male), everything seem to be normal until last Night I noticed that my older cat (6 year old female) was making a “whistle“ sound when she was breathing. Though not all the time it seems to happen when she takes deep breathes and when I pet her. She is eating but very little. She is also acting very strange, it’s like she doesn’t care and ignores me even when I call her and she just seems like she is lacking energy and moves slowly. I’ve also noticed that she is somewhat distant, is this something to be concerned about? Should I take her to the vet?