This is one of the most common turtle killers in captive care. I have lost a few to this as well. Pneumonia can manifest itself in many of the ways listed below, but there are others I have not listed as they are not as common. Pneumonia is not something you can tell right away. The turtle usually will begin to exhibit sighs, most common of which are listed below, but other times they will carry it for several months without showing any signs or symptoms of being sick. An example: One of my red ear sliders, Frisbee, was fine on Friday evening before we went out of town. Sunday night, he was listing (swimming crooked, one side leaning lower than the other). A week or so later with treatment, he was 100% again and has not had any further problems. On the other hand, Thorn, an Argentine Snakeneck Turtle, showed no signs until near death. Tests were conducted ($$$) by a qualified herp vet (to include Radiographs and CT Scan), who diagnosed the problem as Necrotizing Pneumonia (deteriorating the lung tissue itself). This condition was estimated to have begun almost 1 year prior to showing any signs, and could have continued until death had I not gotten lucky and happen to see Thorn cough of a small amount of lung tissue. After studying the turtle for several hours, I was only able to witness any signs of pneumonia this one time. Rather scary, just ensure that you maintain proper preventative measures.

Keep the water temp, ambient air temp and basking temps in a comfortable cushion, as per the needs of that particular species. Ensure that the ambient air temp does not fall below the temp of the water. If it does for a few hours (ie: during the night) then that is normal and natural in the wild. Several cases of pneumonia have been caused by this easily preventable condition. Another way of preventing pneumonia, is to keep the turtles away from drafts, such as under or near open windows, especially in the winter. In our early days, we lost a slider to pneumonia this way.

Another name for swimming crooked is listing. This is when one side of the turtle is lower than the other while swimming. This is because there is fluid in one of the lungs, moreso in one than the other, or there is fluid in only one of the lungs. This is usually, although not always, accompanied by one or more of the other listed symptoms of pneumonia.

If the turtle can't seem to submerge (usually with the front end trying to swim down but the back end keeps floating) there could be two possibilities. The first is a respiratory infection. The second is a gastrointestinal problem. Problems with the GI system are typical after a regimen of antibiotics. The medicines kill off too much of the gut flora and the turtle begins having difficulty in digesting food. This could be a minimal as the turtle releasing the gas or as severe as needing veterinary treatment. If the situation continues, a vet should be consulted.