I have a 7 year old cat with a history of inflammatory bowel disease that has been controlled for the past 4 years by diet alone (novel protein). Other than that, she has been relatively healthy, with her only illness in the past 2 years being a cold. Within the past month, she has had an episode of vomiting that I believe may have been caused by pipes in her water fountain that needed cleaning. Although she is an indoor cat, she is a hunter who often eats spiders and centipedes, which enter the house from time to time. Occasionally, she sits outside in a screened in porch. We have rodents in our forest-like yard in New Jersey, which include ground hogs, squirrels, voles, and rabbits. There are some animals which have burrowed under this porch, which I believe may be bunnies. Yesterday, I discovered 2 notty masses in the submandibular area on the right side. Last week, my husband used the same brand of cat food but substituted chicken for rabbit, which created some vomiting and loose stools. I changed the food back to rabbit on Saturday, and her stools immediately started to reform and she was doing much better and springing back to normal. Then, suddenly these masses appeared, she became listless, lost her appetite. This was far more concerning to me than the IBS symptomatology which had been fast responding to diet. The vet has ruled out a dental abscess, but she saw some protrusion and redness in the throat corresponding to the submandibular area. She has taken cytology, but I do not believe that she has taken any cultures. She gave an antibiotic of convenia in case it is an infection. I believe with the rapid onset of the symptoms that this may be some kind of infection or bite if it is not something cytological? Do you have any hypotheses or experiences with this sort of strange symptoms?

Optional Information:
Type of Animal: Domestic Short Hair Cat
Gender: Female
Age: 7

Already Tried:
Dr. is doing blood work and cytology. Gave convenia injectible, as well as metacam and cerenia (injectable).