Bartonella may make you think of cat-scratch fever, but it is being recognized as the cause of a potentially serious illness in dogs and people. Bartonella is a bacteria spread by fleas, although it is widely believed—but not definitively proven—that a dog also may contract bartonellosis from a tick or cat scratch or bite.
What’s worrisome is that, in cats, this disease is mostly an asymptomatic or transient problem until it is shared with a person or a dog. In both people and dogs, bartonellosis often shows up with cardiac signs. Endocarditis of the aortic heart valve with large lesions can lead to arrhythmias and inefficient cardiac performance. Lymph nodes may blow up and become inflamed. Nasal cavities may be involved, and you might notice nosebleeds. Researchers from North Carolina State believe some joint problems and neurologic symptoms such as weakness may also be attributable to bartonellosis.
According to the Centers for Disease Control and Prevention, Bartonella in dogs usually involves the aortic valve and is characterized by massive vegetative lesions. Signs include:
- Fever
- Endocarditis and myocarditis
- Granulomatous lymphadenitis
- Cardiac arrhythmias
- Granulomatous rhinitis
- Epistaxis
Bartonella Diagnosis Is Difficult
Serology is not always accurate, and cultures take time. These “stealth” bacteria hide in blood cells and many other cells and are not detectable on smears. The bacteria may remain in your dog’s body, not causing any problems until years later when your dog’s immune system is compromised for some reason.
Treating Bartonella in Dogs
Treatment is done to reduce the bacterial load, but most researchers say it will not eliminate the infection. At this time, researchers recommend only treating dogs with clinical signs of bartonellosis. Treatment involves antibiotics such as doxycycline, amoxicillin, enrofloxacin, or rifampin. These drugs must be given for a month or six weeks.
Edward Breitschwerdt, DVM, of North Carolina State, is working toward developing a vaccination. He found that many tissue samples from dogs with the cancer hemangiosarcoma contain bartonella DNA. Any causal relationship is unknown, but he plans to pursue evaluating the connection.
All this is a reminder that disease can be spread by external parasites, making strict flea and tick control a year-round necessity.
