A 2-year-old male neutered American domestic shorthair cat is brought to the clinic by his owner for further evaluation. The cat has been lethargic and anorectic on and off for approximately 6 weeks. Treatment with an oral NSAID and antibiotic resulted in improvement until 2 weeks ago. The owner tells you that now the cat's appetite has decreased and there is visible weight loss with a distended abdomen. The referring DVM's lab work from the initial visit 6 weeks ago showed increased serum globulins.