Does Chronic Infection of Toxoplasma gondii Affect Behavior in the Domestic Cat?

Domestic cats play pivotal roles in transmitting the parasite Toxoplasma gondii, as this parasite reproduces sexually only in felid intestines. The behavioral-manipulation hypothesis predicts that a parasite will specifically manipulate host behaviors essential for enhancing its transmission. In line with this, T. gondii alters risk averse, exploratory and locomotory behavior of rats to increase the likelihood of their capture by cats. Since 18-80% of domestic cats are seropositive for T. gondii, it is important understand whether it manipulates cat behavior to influence its spread. Therefore, we employed a behavioral experiment to evaluate behavioral patterns that were, based on studies in rodents, predicted to be altered by parasite exposure. Cats exposed to T. gondii showed specific behavioral differences in their affiliative behavior. Unlike rodents where predator and control scents trigger different behavioral responses in infected animals, however, differences in affiliative behavior were not dependent on whether cats were presented with predator or control scents. Cats did not vary in their exploration/locomotion, calm or fearful behaviors based on prior parasite exposure