Dwarf with possible pneumonia

Question
Dear Devin,

Hello! I had a question for you about my recent, sad, hamster experience. I had a dwarf hamster (a Campbell, I think, with red eyes) that was about 7 months old. On Saturday, I took him out and played with him for about 15-20 minutes, and he seemed quite normal and active. A few hours later, he was sitting in the middle of the cage, breathing slowly, and was very listless/ unresponsive. We took him to the emergency vet, where they diagnosed him with "possible pneumonia," based on the x-rays, and put him on oxygen, antibiotics, and hand feeding/watering. Despite these efforts, my poor little hamster passed away. I was quite devastated!

I would like to get another in the future, but I wanted to make sure that if there was something I could have done better, that I will do it for the next. He had not seemed ill at all. He liked to hide between the wall of his cage and the igloo, which I read was a possible sign of illness, but he was also quite active and seemed healthy and responsive, with no other signs of illness (runny nose, etc...), and his sudden turn for the worse was a very sad shock indeed.

Details:
-used a wire cage with plastic cat-litter-pan-like bottom
-used Carefresh Ultra bedding, changed weekly, everything scrubbed with warm water, soap, rinsed and dried (I know that Carefresh is supposed to be dust-free, although it always seemed a bit dusty to me. Is there something less dusty?)
-made sure water bottle was full, food was fresh (fed a "tropical hamster feed mix" with pellets, seeds, and dried fruit/corn), occasionally given one cat treat as a treat
-used apple wood chews
-had a plastic igloo, toilet paper tube (changed weekly), wheel, ceramic food dish and plastic hanging H20 bottle
-as it was the summer, I occasionally put an ice cue or two in a separate bowl in the corner to help keep the cage cool--he seemed to like gnawing on the ice cubes!
-I always did my best to wash my hands before handling him.

I was very saddened by his suffering and early death, and want to make sure I do not inadvertently cause something bad to happen to my next hamster. If you have any insights or suggestions, I would greatly appreciate them!

Thank you for taking the time to read and respond to my inquiry!

Best,
Alexandra

Answer
I must say, few people take as good care of their hamsters as you did. My condolences for your little friend.

Often, water can leak from the water bottle and wet the litter in the cage. A good, solid wall water bottle with a ball/spring spout can work so much better than the ceiling drip style. Make sure the ball has a good seal with the spout to prevent leaking. Since pneumonia is an infection, I would suggest getting all new products for your new hamster to prevent it from becoming ill as well. Stay away from lower-end cages and cheap plastic, as these break and wear down very easily. I find it best to look at customer reviews on Petco.com or a similar pet store website before buying a cage. An occasional piece of cat food rather than cat treats is more acceptable. I always like to use the Clean-n-Comfy brand with the Purelite Process. It smells good, keeps the odor down, is very absorbent, and hardly has any dust at all. Wood chews are great and a necessity. The igloo is fine; you might want to use fluff bedding for your hamster to sleep in. Hamsters have an instinct to gather soft materials to nest and burrow in. Ice cubes are fine, but keep it down to 1 ice cube and make sure it does not overflow the bowl when it melts. Continue washing your hands before as well as after (for your own health) handling your hamster.