Yesterday featured a trip to the vet, which Domino considered little better than gratuitous torture. She was not a happy cat, especially since this visit included drawing a blood sample, which she's never had to endure before.
Hopefully her problems aren't major. She's lost a couple patches of fur lately and is sporting some small sores. I gave her an extra dose of flea medicine, but that didn't do anything. The vet, however, confirmed that it was indeed a flea allergy, and recommended that I thoroughly de-flea the house using carpet powder or spray. If anyone has any recommendations in this area, please leave them in comments.
As some of you have noted in comments, she also looks thin these days, and she's been eating a little less than usual. I don't have a scale accurate enough to check this for sure, but the vet does and Domino has indeed lost weight. Thus the blood tests. We'll find out what's up later today.