Cat amyloid serum protein is normal within 5. SAA (feline serum amyloid A) is an acute-phase protein and a sensitive marker of inflammation and tissue damage in cats. SAA begins to increase about 3-6 hours after viral and bacterial infection and reaches a peak within 24-48 hours. , the elevated concentration can reach 100 times. Feline serum amyloid is often used clinically as an indicator to judge inflammation. If the serum amyloid value is higher than the normal range, it indicates inflammation in the cat's body.