Bordetellosis in cats is somewhat difficult to diagnose, because the causative bacterium, Bordetella bronchiseptica, causes clinical signs that mimic those caused by other infectious agents. Bordetellosis in cats often looks like other upper respiratory tract infections, such as feline rhinotracheitis (feline herpesvirus 1), feline calicivirus infection, Clamydophila felis infection and other infectious causes of feline pneumonia. A definitive diagnosis requires identification of the specific bacterial or viral culprit. Many veterinarians suspect bordetellosis based on taking a complete history from the cat’s owner and performing a thorough physical examination. This disease often goes away on its own without treatment, and many cats have only mild symptoms, if any. After the initial history and physical examination, the attending veterinarian may decide to treat the cat based only on its symptoms of upper respiratory tract distress (problems or difficulty breathing, medically referred to as “dyspnea”).
Diagnostic Procedures for Feline Bordetellosis
After the initial evaluation, most veterinarians will take blood and urine samples to assess the cat’s overall health. These typically include a complete blood count (CBC), serum biochemistry profile (chem panel) and urinalysis. Many cats that are infected with the Bordetella organism are also suffering from other causes of upper respiratory tract disease. Thorough blood and urine evaluation, including feline leukemia and feline immunodeficiency virus tests, are normally performed to round out the assessment of the causes of the kitty’s condition. The attending veterinarian may also recommend taking thoracic radiographs (chest X-rays) to assess the possibility of pneumonia. Unfortunately, the results of all of these tests are often unremarkable and inconclusive in cats with bordetellosis. Advanced testing includes doing a culture and sensitivity assessment of the cat’s blood, oral, lung and/or nasal secretions, which involves trying to grow the offending bacterial organisms in the laboratory. The veterinarian will take swab samples of secretions from the cat’s nasal passage and/or from its throat, and may take other samples with other techniques, and will get a urine sample as well. The samples will be placed into sterile tubes and sent to an outside laboratory for culture and microorganism identification. Isolation of Bordetella bacteria where the cat is obviously ill is fairly easy. It’s much more difficult to isolate Bordetella from samples taken from cats who are chronic carriers of the organism but don’t show any signs of being sick, because many healthy cats will have positive cultures for Bordetella bronchiseptica. Outside laboratories can take 48-72 hours to produce results. As a result, many veterinarians make an initial diagnosis of bordetellosis based upon the cat’s history and clinical presentation, especially if the cat lives, or recently lived, in an area housing multiple cats or in a household with a dog that was recently diagnosed with bordetellosis.