? Sudden sneezing with bloody nose, possible URI or nasal cavity growth/mass?

[MISSY + Simone&MICIO (GA)]

Last night, after midnight meal and right after I brushed her teeth, Missy started sneezing 5-6 times in a row and I saw some blood coming from her nose. I panicked and called the ER and they told me to take her to regular vet next morning since no other symptoms were present. Took her to the vet (a substitute Dr., not my regular vet) and, after barely visiting her, she quickly offer a CONVENIA shot for possible URI; because lately I noticed Missy breathing gotten noisier, especially when eating, and to me it sounds like there's something inside her nasal cavity or so.....for some reason I'm thinking either a polyp or something else.
Occasionally Missy would sneeze when grooming herself or rubbing her face/whiskers on the scratcher but not usually and she never had any discharge on her eyes or nose of any kind, never had an URI or any viral issues either and she's only indoor cat with no contacts with any other pet/animals.....
With IBD, CKD and Pankreatitis present, I decline the Convenia shot; the vet then offer I believe Clavamox and I said I will think about it...seems to me she was pushing for antibiotics like if they were treats!
At the end the vet proposed a specialty visit for a possible scope, MRI or some sort of imaging, but first available appointment will be on 2 weeks.

WHAT WOULD YOU DO? DOES ANYBODY HAD EXPERIENCE WITH CATS WITH NASAL POLYPS/MASSES? WHAT WERE THE SYMPTOMS AND HOW WERE THEY DIAGNOSED?
I never thought Convenia is a safe medication unless there's clearly an infection or something that bad going on... Only 2 weeks ago I've finally got Missy to slowly stop Budesonide after several years and don't really want to mess up her gut with unnecessary antibiotics.
Tnx in advance.

 

[MISSY + Simone&MICIO (GA)]

UPDATE: IM doctor emailed me back and, based on Missy case and signs, bloody nasal discharge in an older cat can be from a number of things ranging from severe dental disease, to a foreign body, to inflammatory nasal disease to a tumor..., she would also first try a course of antibiotics to see if it helps before jumping to more invasive testing (blood work, anesthesia, ct scan, rhinoscopy, chest radiographs, biopsies) and in this case she would require Missy to be dropped off at the clinic for the day, fasted and only 1/2 dose of insulin (about 2u).
I am now leaning towards the antibiotics as the first course of action too....between Convenia and Clavamox, which one would be best to address a possible mouth/nasal infection? My biggest concern with antibiotics is Missy's IBD and CKD.
@Diane Tyler's Mom , @Suzanne & Darcy , @Wendy&Neko, @Bron and Sheba (GA) , @tiffmaxee I could use your suggestions if you could. Tnx in advance

 

[tiffmaxee]

If my cat I would not give convenia. It’s tempting because no risk of intestinal upset but a broad spectrum antibiotic has a better chance of working and convenia does not qualify.

 

[Diane Tyler's Mom GA]

I'm sorry I don't know much about antibiotics , I hope other members will get back to you

 

[Wendy&Neko]

For mouth issues, Clindamycin is what I've been told is a good antibiotic. (used it myself as well as with Neko). But it is strong, so a good probiotic should also be given. If it's not a choice, I'd do Clavamox over Convenia.

 

[MISSY + Simone&MICIO (GA)]

If my cat I would not give convenia. It’s tempting because no risk of intestinal upset but a broad spectrum antibiotic has a better chance of working and convenia does not qualify.

Right and that's why it'll be a tough decision. Just don't understand why many vets are ok with Convenia and say it's very safe while, my old vet (now retired) was totally against it when at the ER they give that to my Micio when he started with tooth infection over a year ago, especially bad for ckd

 

[MISSY + Simone&MICIO (GA)]

For mouth issues, Clindamycin is what I've been told is a good antibiotic. (used it myself as well as with Neko). But it is strong, so a good probiotic should also be given. If it's not a choice, I'd do Clavamox over Convenia.

I believe the regular vet offered Clavamox but not sure...I am now waiting on the IM response which it may take up till next week