DIAGNOSIS:
Clinical signs (see above) are indicative especially in purebred catteries & /multiple cat households in cats <4years of age.
Laboratory diagnosis: Best done with the help of a specialist lab, eg Glasgow Veterinary School, who will look for a range of indicators - high FCoV antibody titres (note that many cats have FCoV antibody but do not develop FIP), a low albumin : globulin ratio (because globulin levels are usually greatly raised in FIP), high levels of the glycoprotein AGP, low white cell counts. Characteristic lesions in appropriate tissues at post-mortem. Virus identification is not usually attempted ante-mortem but there are recent claims that PCR can be used to identify a FIPV-specific nucleotide sequence.