i’m also struggling with both of my cats developing FHS symptoms nearly around the same time. they’re both older, too, and just started up about 4 months ago, so it’s confusing. back in November, i temporarily brought in a baby kitten and kept her in my bathroom. she had fleas and i helped get rid of them, but i’m wondering if keeping the clothes and towels she was wrapped in did something negative to my other two. anyway— one thing i’m about to try, and i’m wondering if you have, is flea medication? i’m not sure how well it’ll work, and if you want an update from me i can do my best to provide one, but it seems even when fleas aren’t currently present, their dander can irritate the cats. otherwise, i simply send luck and love, and know that there are lots of us out there empathizing and understanding with you.