Laboratory profiles in cats with different pathological and immunohistochemical findings due to feline infectious peritonitis (FIP)

Abstract

Blood was collected from 55 cats with feline infectious peritonitis (FIP) and from 50 control cats in order to define whether differences in pathological findings and in distribution of feline coronaviruses (FCoV) can be associated with changes in haemograms, serum protein electrophoresis, and antibody titres. Compared to controls, the whole group of FIP-affected cats had blood changes consistent with FIP. Based on the pathological findings or on the immunohistochemical distribution of viral antigen, FIP-affected cats were divided in the following groups: subacute against acute lesions; low against strong intensity of positivity; intracellular against extracellular positivities; positive against negative lymph nodes. Lymphopenia was more evident in cats with acute forms, strong intensity of positivity, extracellular antigen and negative lymph nodes. Cats with positive lymph nodes had the most evident changes in the protein estimations. These results suggest that differences in pathological findings might depend on different reactive patterns to the FCoVs.

Fig 1.

Lung; cat, domestic shorthair, male, 8 months. Severe, acute, diffuse fibrinous pleuritis with scattered inflammatory cells. HE stain. Original magnification, 200 ×.

Fig 2.

Lung; cat, domestic shorthair, male, 1 year. Severe, subacute, diffuse fibrinous pleuritis with organised fibrin and large lymphoplasmocytic foci. HE stain. Original magnification, 200 ×.

Fig 3.

Spleen; cat, domestic shorthair, female, 3 months. Severe, subacute, diffuse fibrinous perisplenitis with rare FCoV-positive cells. Avidin biotin peroxidase complex method, Mayer's hematoxylin counterstain. Original magnification, 200 ×.

Fig 4.

Intestine; cat, persian, female, 8 months. Severe, subacute, diffuse fibrinous peritonitis with many FCoV-positivities. Avidin biotin peroxidase complex method, Mayer's hematoxylin counterstain. Original magnification, 200 ×.

Fig 5.

Liver; cat, domestic shorthair, female, 1 year. Pyogranulomatous hepatitis with prevalence of intracellular positivities. Avidin biotin peroxidase complex method, Mayer's hematoxylin counterstain. Original magnification, 400 ×.

Fig 6.

Kidney; cat, domestic shorthair, male, 7 years. Pyogranulomatous nephritis with presence of intracellular and extracellular granular positivities. Avidin biotin peroxidase complex method, Mayer's hematoxylin counterstain. Original magnification, 400 ×.

Fig 7.

Lymph node; cat, persian, female, 8 months. Presence of viral antigen in the germinal centres of the lymph node. Avidin biotin peroxidase complex method, Mayer's hematoxylin counterstain. Original magnification, 100 ×.