Summary on Section 7: Diagnosis of FIP; Section 7.6: Indirect Detection of FCoV:  Serum FCoV antibody tests, performed on blood, are usually enzyme-linked immunosorbent assays (ELISA), indirect immunofluorescence antibody tests or rapid immunomigration tests.  A positive FCoV antibody test indicates that the cat has been infected with FCoV and has developed antibodies. Although cats with FIP tend to have higher FCoV antibody titres than cats without FIP, there is much overlap, so there is little value in an individual cat undergoing serum FCoV antibody testing. In addition, negative serum-FCoV antibody results cannot rule out FIP, as cats with confirmed FIP can be FCoV antibody-negative.  There is no ‘FIP antibody test’; all that can be measured is antibody against FCoV.