Hi, I'm Dr. Bonk. I'm sorry to hear about Bobbi's troubles. Sneezing can occur for a large number of reasons. Sneezing is a result of irritation to the nasal passages. It can be brought on by allergens, dust particles, or viral or bacterial infections. Typically bouts of sneezing are due to a more prolonged issue such as an allergy or infection.
There are a large number of virus's that affect a cat's upper respiratory system. Some of these viruses are never completely cleared by the immune system, so the cat is infected for life. They go through periods of latency and then can flare up due to some kind of stresser. The most common one is a form of the herpes virus. Cats infected with this have periods where they show no outward symptoms but then will have bouts of sneezing and possibly a clear discharge from nose and eyes. These bouts are usually self limiting and only require treatment if they get a bacterial infection on top of it. Most bacterial infections will present with a thick, colored discharge and usually the cat is more lethargic. If a secondary bacterial infection does not occur, the cat usually returns to normal within a few days.
There is no real treatment for these persistent viral infections. Sometime supplementing with lysine helps to prevent flare ups, but the best thing to do is provide supportive care during the flare up and avoid known stressors.
Allergies are another common cause of sneezing. These are usually brought on by change, so change in season, food, cleaning products, etc. These are best treated by removing the allergen if known and sometimes by giving an antihistamine such as Benedryl. Again, these cats are usually not real sick unless the irritation leads to a bacterial infection as well.
Short bouts of sneezing can be brought on by dust particles or other minor irritants. These bouts usually consist of a couple of sneezes to clear the nasal passages and then the cat returns to normal.
If Bobbi develops any kind of thick or colored discharge from the nose or eyes, or if she becomes lethargic or has a decreased appetite, it would be time to consider a vet visit. Also, if the periods of sneezing are becoming more frequent or longer in duration, it may be time to get her checked out.
I hope this helps. Please contact me with any further questions you may have. Thank you and good luck!