Hello, I'm Dr. Deb.
I recently came online and see that your question about Sugar hasn't been answered. I'm so sorry that you've had to wait for a response, but if you still need assistance, I'd like to help if I can.
It sounds like Sugar may have an upper respiratory infection if the color of the discharge she's producing in green or yellow. However, there are other possible explanations for her symptoms such as allergies, nasal mites, polyps, a foreign body or even a sinus infection.
Unfortunately, if she does has an infection, then she'll probably need systemic antibiotics before significant improvement is seen but
there are a few suggestions which may help improve the situation.
1. You can use a sterile saline nasal spray twice a day which can help to flush out her nostrils although she probably won't like it very much as you might suspect.
"Little Noses" Saline Spray/Drops (non medicated) is an example of what I mean.
2. On the off chance that there may be an allergic component to her symptoms, over the counter Benadryl (aka Diphenhydramine) can be given at a dose of 1 mg per pound of body weight twice a day. Sedation or lethargy can often be seen as a side effect so I wouldn't want you to think she was getting worse if she seems less active.
3. Humidifying the air can help some patients but depending on where you live, it may already be quite humid.
If the discharge continues to be greenish or yellowish in color, though, a vet visit may be prudent
I hope this helps although, again, my profuse apologies for the delayed reply. Deb