Table 1.

Histopathological findings of cats vaccinated with a FVRCP vaccine for intranasal administration (IN) or sensitized with CRFK lysates and biopsied 2 weeks after the last booster

Cats	Histological descriptions
IN vaccine cat 1	No significant microscopic lesions.
IN vaccine cat 2	Mild mesangial thickening and hypercellularity. No significant interstitial inflammation or fibrosis is present.
CRFK 10 μg cat 1	Glomeruli are shrunken with marked mesangial and Bowman's capsule fibrosis. Interstitial infiltrates of mixed cells (lymphocytes, plasma cells, fewer macrophages with an occasional neutrophil) are marked. Inflammatory cells replace extensive segments of tubules and glomeruli. Interstitial fibrosis is moderate.
CRFK 10 μg cat 2	No significant microscopic lesions.
CRFK 50 μg cat 1	Glomeruli are normal. Multifocal interstitial infiltrates of mixed mononuclear cells (lymphocytes and plasma cells) are mild and replace segments of tubules. No significant fibrosis is present.
CRFK 50 μg cat 2	Mesangial thickening and hypercellularity is mild but no interstitial inflammation or fibrosis is seen.
CRFK 50 μg cat 1 (with alum)	Glomeruli are normal. Multifocal interstitial infiltrates of mixed mononuclear cells (lymphocytes and plasma cells) are mild and replace segments of tubules. There is no significant fibrosis.
CRFK 50 μg cat 1 (with alum)	There are no significant microscopic lesions.