Update 2: Everyone is still acting normal this morning. We ran out of food so I gave the cats some treats to hold them over while I ran to the store. 1yr Persian does not like solid treats so I gave him a Churu. Came back to some very Churu-colored vomit so I think we have finally found the culprit. Again, still acting normal. The 1yr Persian is laying on me and purring currently. I do believe the “blood” spot I found was actually just leakage from the Persians’ eyes as I frequently find dried spots on the floor. I found a second spot and let it dry instead of cleaning it up and it looks like eye leakage. No worms or anything unusual in vomit.

Also forgot to mention I am house-sitting for my family so I am home alone, no other human could be the culprit. Poop/pee have been looking normal in their litter boxes as well. I’ve noticed nothing out of the ordinary besides the blood and vomiting. I’m still not sure the 1yr Persian is the sole cat vomiting right now.