I have a 6 year old red eared slider. He was my friends until recently when she moved and I took him for her. He never had any heat lamp or UVB lamp he had a little heater and only ate a high protein diet. Right before I got him his eyes swelled shut and he would sleep all the time. I figured this was due to his habitat and eating.
He now is in a 20 gallon tank, has a big basking area with a heat lamp and UVB lamp his water has a filter and heater and the temp is always around 79 degrees. I got eye drops for his eyes and gave him vitamin baths because he wouldn't eat anything. His eyes are getting much better and he is always in the water when his lights are off. But he still basks most of the day and now his head is bobbing a lot when breathing. I have caught him "yawning" a few times in the past few days and he occasionally seems irritated by something and then either stretches his neck or yawns. I have only seen this about 4 times in 2 days and he is back to eating. He is swimming fine and has no bubbles around his nose out of the water. I also don't hear him gasping for breath he mostly just lays his head on his rock all day.
Could he be starting an RI or is he getting over a general sickness with a little bit of RI? Besides his breathing/yawning he seems to have improved a lot from when I first got him. Why is he now getting an RI?
Any help would be great!!

