My cat is almost 12 years old. She is indoor-only. For two years now, she’s been in remission from a nasal lymphoma. She had her nasal passages scoped and they removed what they could of the tumor and she was put on a high dose of prednisolone. Since then, she’s been doing very well. Sometimes she will have a bit of a snuffly sigh when she’s breathing, but otherwise none of the symptoms she had prior to the treatment. She has had side effects of the medication, namely thin skin, slow healing, and some weight gain although she’s on a pretty controlled diet of wet food. About 24 hours ago, I saw that her nose was running on one side and sometimes she sneezes. Otherwise she seems normal. Her appetite is good as usual. Should I be worried? Is the tumor returning or could it be something else?