We got the results of Jasper's final bloodwork back, and they were good. After three months of daily injections followed by three months of observation, Jasper is officially considered cured of FIP!!
Jasper was a little over a year old when he suddenly got a bit lethargic and started to lose interest in his food. This went on a couple days when I noticed labored breathing and took him to the emergency vet. Our vet told us that we have to put him down, and I was devastated until we discovered this treatment. We got him started within a couple days, and he got better almost immediately. It was expensive for us (We're poor!) and a stressful process, but I am so, so glad we did it.
It was hard to get a picture of him this morning because he is too busy running, hopping, and cantering to sit still for long... Also, look how big he is now! He gained almost three pounds!