Cat Bartonellosis: Cat Scratch Disease and Feline Welfare

Bartonella henselae causes cat scratch disease in humans and can cause chronic illness in cats, particularly immunocompromised individuals; understanding transmission helps protect both feline and human welfare.

Key Facts

Bartonella henselae is transmitted between cats primarily through cat flea (Ctenocephalides felis) faeces.
Cats are the main reservoir host for Bartonella henselae and can carry the bacterium without showing illness.
Cat scratch disease in humans typically causes swollen lymph nodes, fever, and fatigue following a scratch or bite.
Kittens and young cats have higher bacteraemia rates than adult cats, making them higher transmission risk.
In immunocompromised cats, Bartonella can cause endocarditis, uveitis, and neurological signs.
Flea control is the most effective strategy to reduce Bartonella transmission within cat populations.
Cats do not typically require treatment for Bartonella unless showing clinical signs of disease.

Welfare Considerations

Bartonella rarely causes overt illness in healthy adult cats, but its welfare implications are most significant in immunocompromised cats where it can cause serious systemic disease. Additionally, cats that transmit Bartonella to immunocompromised human family members may face re-homing pressures — a welfare risk for the cat. Comprehensive flea prevention eliminates the primary transmission route and protects both cats and their human companions. Veterinary testing for Bartonella is warranted in cats with unexplained uveitis, heart disease, or neurological signs.

What You Can Do

Maintain year-round veterinary-prescribed flea control for all cats, particularly those with outdoor access.
Teach children to avoid rough play that leads to scratches, particularly with kittens.
Immunocompromised individuals should consult their physician and vet about cat ownership risk management.
Do not re-home cats solely based on positive Bartonella serology — focus on flea control instead.