Final answer:
In suspected cases of feline infectious peritonitis (FIP), a cat would typically have a normal PCV with high TP measurements, due to the accumulation of protein-rich fluid in the body cavities and increased concentration of globulins.
Step-by-step explanation:
The expected packed cell volume (PCV) and total protein (TP) measurements in a cat presented with suspected feline infectious peritonitis (FIP) would most likely be a normal PCV with a high TP, which corresponds to option A. FIP is an immune-mediated disease, and one of the hallmarks of the effusive (wet) form is the accumulation of protein-rich fluid in the abdomen or chest. Increased protein in the fluid is due to the leakage of protein from the blood vessels into body cavities.
While the PCV might remain within normal limits, the TP is often elevated because of the increased concentration of globulins, which are produced as part of the immune response to the virus that causes FIP. Additionally, a key diagnostic feature of the effusive form of FIP is the high protein content in the effusion. Note that definitive diagnosis of FIP involves additional testing beyond just PCV and TP measurements, as it often requires a combination of clinical signs, laboratory findings, and sometimes more specific diagnostic tests.