I'm sorry your little guy is going through this. Based on what you described – the goopy, sticky eye discharge that crusts over, plus the periodic wet cough and wheezing – feline herpesvirus (FHV-1) is definitely a possibility. It's very common in cats, especially if they had exposure as kittens, and it can cause both respiratory symptoms (sneezing, coughing, congestion) and eye issues like conjunctivitis.
Asthma usually causes coughing or wheezing without eye involvement, but allergies could cause some similar symptoms too. Sometimes herpes flare-ups happen after stress or immune dips, and the eye and lung signs can appear together if it's a flare.
What you can do until your vet visit:
✅ Keep his eyes clean. Gently wipe away discharge with a warm damp cloth or sterile saline wipes a few times a day.
✅ Monitor eating and hydration. Offer strong-smelling wet food or warmed-up food to encourage eating. Make sure he's drinking water.
✅ Use a humidifier or steamy bathroom sessions. The moisture can help loosen mucus in his airways.
✅ Reduce stress. Keep him calm and comfortable, away from drafts or anything that could irritate his eyes or breathing further.
❌ Don't use any human eye drops or leftover meds. Only use what the vet prescribes once you get in.
If he stops eating altogether, is breathing with his mouth open, or seems extremely lethargic, I'd recommend calling an emergency vet sooner just to be safe.
Feel free to visit this informative article on how to open a chewy account for all your pets needs.
You're doing the right thing by getting him checked. Hope he feels better soon!