Unsure if it’s just me and my browser, but the video is only audio for me.
One thing that stands out to me is “completed treatment… three times now”. — If treatment was completed, it should not have to be repeated. This leads me to two thoughts: 1) each treatment was ended before all the infection was cleared, allowing time for it to regrow and come back again, thus the infection was never fully treated and 2) if the infection has truly been treated, yet re-infects and impacts Rainn, there is something going on dampening Rainn’s immune system, making her vulnerable to this. I feel that if it was the latter, you’d see other problems. The former (i.e. prematurely stopping antibiotic tx for a URI) is very common. How long were each medication course of treatment?
The fact that it’s a dry sneeze for such a long time is notable. It is possible that something is happening with the teeth that’s irritating the sinus cavity as well — I think an xray is a good next assessment.
I think the only thing as of now is getting assessment and treatment. If environmental irritants make it worse at all, trying to dust and vacuum more often, but if it is an anatomical/infectious issue, that won’t help too much.
The answers provided in this discussion are for general guideline purposes only. The information is not intended to diagnose or treat your pet. Seek the advice of your veterinarian or a qualified behaviorist.