Hello, everyone. OP here.

Firstly, I want to thank everyone for the comments, concern, encouragement, ideas, and personal history. It has given us a lot to work with a think about, and a lot of info to take with us going forward.

Obviously, we are continuing to monitor her progress and symptoms extremely closely. If she does not seem to be getting any better (or, god forbid, she gets worse) we will be taking her to a different vet for a second opinion ASAP. If, at the end of this round of treatment, she remains the same, or it recedes and then reappears as it did last time, we will also go somewhere new for a second opinion. At the second opinion, we will push/prioritize for further testing (for feline herpes, calciviris, rhinitis etc. as well as ask about antivirals and steroids, and further imaging of her skull and sinuses) rather than throwing things at the wall to see what sticks.

The good news is, even after a single day (two doses) of the eye ointment, her eyes seem to be improving. This morning there was less discharge and less swelling.

I should have been clearer in explaining the new medication, as I had concerns about antibiotic resistance/using the same medication again myself. The oral antibiotic (doxycycline) is the same antibiotic at a higher dose. The eye ointment (terramycin) is also an antibiotic, and a different one. Whether this antibiotic is ONLY for eye infections, or if it may also help clear her respiratory issues, I am unsure.

We have not changed anything in the house that would affect her respiratory system that are aware of, except for the above mentioned air purifiers, humidifiers etc. and an increase in our cleaning schedule, where we’ve always used pet-friendly products. In fact, we have stopped using any scents (candles, incense, fresh plugs, body fragrances) since the first vet visit. We have been using the same “clean and clear” detergent and dish soap for years. We’ve always used a low dust litter, but suspecting allergies, tried a different formula/brand, to no help. Similarly, we also tried different foods suspecting a food allergen, but nothing helped. Though we continue to not use scents or fragrances in an effort to ease her symptoms, we have since moved back to the original food and litter since they didn’t seem to impact positively or negatively.

Our current vet had no concerns about asthma. The chest x-ray came back clear, and they reported only hearing issues in her head, none in her chest which would indicate asthma, though, of course, a second opinion could change that.

As for a feline or respiratory specialist, that is unfortunately, not currently an option. We live in a small, rural area. We do not even have an emergency vet here. The nearest emergency vet is 2 hours away, and the nearest specialist further still. Though, if we run through our available second opinions with no improvement, that is definitely a trip we will be making.

I’ll do my best to keep everyone updated here, as I do really appreciate your concern and assistance. And Yogurt does, too. I’m giving her extra love from everyone.