We had to make a quick trip to the emergency vet last night because a certain kitten chewed off and swallowed the tip of the nipple on the feeder bottle. ~facepalm~ The consensus is that it will probably pass just fine, but no more bottles. This little niblet weighed all of 15 oz. last night.
Today we went for a formal vet exam. The vet says it appears to be a boy, about four weeks old. He has gained a full ounce since last night and is getting more active, so we seem to be winning against the malnutrition and dehydration. He is also able to lap his formula from a tiny saucer and even managed a little meat gruel today. We'll go back in about a month to start worming.
After getting up every few hours to feed last night, I'm damned tired today. The vet thinks we can just leave a little food available to him overnight and resume regular feedings in the mornings now, so I look forward to a long reunion with my bed tonight.