My 5 year old cat, Andy, has had an elevated temperature (103-ish) and very swollen lymph nodes in the neck area for about the past two weeks. He is very lethargic, not very interested in eating, and sleeps most of the day under the bed. I have been to the vet several times, but they haven't been able to determine the cause except to say that it looks like infection. Andy tested negative for feline leukemia several years ago and does not go outside. The only other cat that he is contact with is a 5 year old tabby who also tested negative and does not go outside. He has been taking Clavamox for about 10 days and Baytril for about 5 days. The day after he took the Baytril, the swelling went down considerably and his behavior became much more normal, but it was short-lived. Less than 24 hours later the swelling returned. I am very worried about this sweet cat. Please help.