my tort didn’t have a runny nose or a cough just the swollen closed eyes, he said it could be irritation but couldn’t rule out infections so gave him antibiotics as precaution and drops and cream to apply and he has been great so far, the vet had said it could be cataracts or something more...
my tort bowzer has been exactly the same, you literally described everything we went through, we ended up with a feeding tube and antibiotics and drops and a very hefty bill, and the vet also said it will be a recurring problem with his eyes,