Cause
The cause of Haemobartonellosis is an organism called Haemobartonella felis, a parasite that attaches to the surface of red blood cells in infected cats. Fleabites may be the primary means of spread. The organism can be passed from mother cats to their kittens, but it is not known whether this spread occurs prior to birth, during birth, or through nursing. The organisms may be passed via blood transfusion. Some authors suggest that cat bites may also transmit the organisms.