Kalis visit to vets re sneezing

Question
Dear Dana,

John and I took Kali to see the more experienced vet a couple weeks ago.  He listened to her chest and said her lungs sound clear.  He thought we should just "wait" and see how she was in another week or so.  She is still sneezing, still clear discharge but it is matting her hair around her nose and one of her hands gets matted, but it's all clear, no coloring at all and no stickiness.

We decided to take her to another vet.  He's the best with teeth and a good surgeon.  He said her teeth are great, lungs okay, no fever. Used stethescope to listen to her sinus area. He thinks she's a little congested but said since previous attempts w/antibiotics and no improvement with runny nose, he thought we should try a nose drop.  He gave us Tobramycin-ophtalmic to use twice daily, for the nose, not the eyes. Her eyes are clear, dry and fine.  He gave her one treatment of the drops in the nose before leaving vet office and since I've been home Kali has had several sneezing episodes.  What do you think?  Have others used an eye drop as a nasal drop?  He thinks it will take at least two weeks before we see any sign of change.  If this doesn't work, he would recommend a CT scan. He would look up her nose but he said he'd have to anesthesize her and he'd rather not do that at this point.I may hold off on the drops treatment until I hear back from you in case this is a bad treatment idea.  She's not dying, just sneezing her little self crazy.

What's your take. Thanks, Debbie

Answer
Dear Debbie,

I think you've found a very good vet who has good ideas about how to manage this problem.  Tobramycin drops are a good choice, and might be even more effective if combined with the more expensive ciprofloxacin (or other fluoroquinolone) ophthalmic drops, as these two classes of drugs work synergistically.  (The fluoroquinolone prevents the bacteria from duplicating its DNA properly, and the aminoglycoside (in this case, Tobramycin) inhibits ribosome activity, preventing the bacteria from making any enzymes that could inhibit the activity of the other antibiotic.)

If that doesn't work, then the next step would be endoscopy to see if she has a foreign object up her nose, or even the intrusion of a tooth root into her sinuses (which we see not uncommonly in rabbits over the age of 5).  

Ophthalmic drops are the best choice for this, since otic drops usually contain some form of acetic acid (vinegar!) that's good for controlling the pH environment in the ear, but nasty to have up your nose.  Ophthalmic drops, on the other hand, are very mild and shouldn't bother Kali at all.

I hope this works!

Dana