Date of Award

January 2015

Degree Type


Degree Name

Master of Science (MS)


Veterinary Clinical Science

First Advisor

Lynn Guptill

Committee Member 1

Hsin-Yi Weng

Committee Member 2

Joanne Messick

Committee Member 3

John Christian

Committee Member 4

Annette Litster


Feline immunodeficiency virus is an important lentiviral infection in cats. Infection is life-long and results in immune compromise, increased susceptibility to opportunistic infections and early mortality. Infection is commonly referred to in three stages: acute, (asymptomatic) and end stage (symptomatic); although not all cats will progress to end stage disease. Acute infection lasts several months during which cats may have mild, transient anorexia, lethargy, fever, lymphadenomegaly and diarrhea. There is loss of mucosal and peripheral CD4 T cells, expansion of a subset of CD8 T cells, CD8βlow, and establishment of viremia during this period. Asymptomatic infection lasts a variable period of years during which progressive decreases in CD4 T cells and inversion of the CD4:CD8 ratio occurs. End stage infection does not occur in all infected cats. It is characterized by a rapid decline in health including generalized muscle wasting, treatment-refractory opportunistic infection and / or neoplasia leading to death within months. A marked decrease in CD4 T cell counts and CD4:CD8 ratio and several fold increase in viremia occurs during end stage disease but reported literature is sparse. Longitudinal studies of specific pathogen free cats experimentally infected with FIV infection have focused primarily on acute and early asymptomatic stages of infection. Little has been reported on the transition from late chronic to end stage disease. Longitudinal studies of cats naturally infected with FIV are needed to better characterize the course of infection.