Bartonellosis

GENERAL DESCRIPTION

Bartonellosis is a common disease that is almost always found in cats, but can be found in other pets. It does not usually cause illness in pets, but is easily spread to humans with many cases occurring between the months of September through January. Human infection with Bartonella bacteria is more commonly known as Cat Scratch Fever.

SOURCE & CAUSE(S)

Bartonella henselae is a rickettsial bacteria that is transmitted to cats by fleas. Other species of the Bartonella genus infect other types of pets. When your cat scratches at a biting flea, the bacteria residing in the flea feces gets under their nails. Batonella may then be transmitted to humans by scratching them when playing or protecting themselves. Young children, seniors, and people with a compromised immune system are more susceptible to getting this infection.

SIGNS & SYMPTOMS

In the few cases where your pet does show symptoms, they will usually be mild and short term. They include:

• Fever
• Lethargy
• Loss of appetite
• Swollen lymph nodes
• Muscle pain
• Vomiting
• Eye redness

Humans that have recently been scratched by an infected cat may experience:

• Redness and swelling surrounding scratch site 7-12 days after a cat scratch
• Abcess or small blister surrounding the scratch site
• Swelling of the lymph nodes close to scratch site 1-3 weeks after abcess or blister formation
• Fever
• Headache
• Fatigue
• Muscle pain
• Poor appetite
  

DIAGNOSIS & TESTS

There are several tests available to diagnose your cat with a Bartonella infection, but because the bacteria is not constantly circulating in the bloodstream, they are not always accurate. The diagnostic path chosen will depend largely on the symptoms your pet has, and the availability of diagnostic tools your veterinarian has. Your veterinarian will be most likely to perform one of the following tests:

• Western Blot - This is a very specific test that will test your cat for antibodies against the Bartonella bacteria. It will need to be sent to an outside lab if your veterinarian suspects Bartonellosis in your cat.
• ELISA testing - This stands for "enzyme-linked immunosorbent assay" is a test used to determine if a pet has been exposed to a certain pathogen by seeing if it’s body has produced antibodies against the pathogen. It can be used to test for viruses, bacteria, microbes, or other material. In this case, the veterinarian would take a blood sample and test the serum for the antibodies to Bartonella.
• Immunofluorescence - This is a technique used to illuminate either viruses or their antibodies in a tissue or culture using a fluorescent dye. In this case, your veterinarian will make a tissue or cell smear and expose it to a specific antibody for Bartonella. The antibody will attach to any virus displayed in the sample and show under a microscope as a bright green spot on the slide.

These tests may be falsely negative if your cat is infected but has not yet formed antibodies, if they do not form enough antibodies, or if the Bartonella bacteria is not present in the bloodstream at the time. 

TREATMENT & MANAGEMENT

This bacteria is particularly difficult to treat because it is gram-negative. Gram-negative bacteria have an outer membrane that is complex and hard to penetrate. Therefore, more intensive antibiotics are necessary to treat.

If your cat tests positive for Bartonella, treatment with antibiotics will likely be prescribed. Most commonly, your veterinarian will put your cat on a three week regimen of a drug called azithromycin, but other drugs have proven effective.

PREVENTION & HELPFUL TIPS

Preventing Bartonella infection is done by:

• Keep your cat on a flea preventative to prevent flea bites
• Keep your cat’s nails trimmed to prevent scratches
• Avoid playing too rough with your pet so that you do not get scratched
• Wash and disinfect any cat scratches immediately

There is a way to test your pet for the Bartonella bacteria, but since most pets do not show symptoms, testing is not usually necessary. People that may be more susceptible to the disease may wish to test a cat they are considering adopting.