I sat with him, cleaned him up a bit, fed and watered him and kept an overnight vigil until I could take him to the veterinarian the next morning. After meeting with the vet, based on his weight and size, she believes the the kitten was about 3 weeks old, and although he was pretty sick, he definitely had a chance. It was at this point that the backyard kitten officially became "Keek" and I undertook the role of mama-cat. Two weeks of meds and some hefty TLC later, I can happily say that Keek is doing great and he's actually getting along with my resident cat, the beautiful and powerful Dahli-Bell.
In retrospect, I definitely wasn't in the market for a new cat, let alone the responsibilities of a young kitten, but this little kitty stole my heart. As I write this, he's looking up at me, almost like he knows what I'm saying. Either that, or he wants a snack.
Welcome to the family, Keek!