Bartonellosis [bar-ton-el-lo-sis] is caused by a gram-negative bacterium of the Bartonella genus. It is largely a disease of cats but can affect other companion animals and humans through direct inoculation (the scratch or bite of an infected animal) or through the bite of an arthropod host.

Bartonella species are carried by many wild mammals throughout the world. In its natural hosts, the disease generally appears not to cause symptoms but once it is transferred to domestic animals or humans, symptomatic disease may occur.

Companion animals can remain symptomless, but stressed or immune-compromised animals may become symptomatic.

For details on the signs and symptoms, diagnostic techniques and treatment regimes in dogs and cats, please follow the links right.