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Improving characterisation of respiratory disease in cats

** Please note this study is closed/completed and no longer recruiting patients ** 


To compare findings of thoracic CT combined with BAL fluid analysis and thoracic radiography combined with BAL fluid analysis in cats with respiratory disease.


Respiratory diseases are common in cats but standard radiographs can miss structural changes that could be contributing to clinical signs. Computed tomography (CT) is a 3D imaging technique that provides more precise images of the chest allowing for detection of subtle lesions.   In people, CT is considered to be the best method to evaluate the lower respiratory tract, however it is not usually performed in cats because it requires general anesthesia.  Recently, a new CT technique has been developed in cats allowing cats to undergo CT with mild or no sedation, reducing risks relating to this procedure.

Unfortunately, CT alone cannot provide us with a specific diagnosis, so to achieve this a bronchoalveolar lavage (BAL) needs to be performed. BAL is a relatively safe, minimally invasive technique for diagnosing respiratory diseases in cats. However, in cats the procedure may be more challenging due to the small diameter of their airways.  We have recently developed a modification of a previously described BAL technique.  This modification allows us to be able to maintain a protected airway with an endotracheal tube, provide continuous oxygen supplementation and also specifically sample diseased areas of the lungs.  This is achieved using a soft guide-wire in conjunction with a catheter to fluoroscopically (using a video x-ray) guide location of sampling into a specific lung lobe.  This technique has been successful and safe in 12 healthy cats to sample the caudal lung lobes as well as in 3 other patients in the middle lung lobes.  However we need to confirm that the catheter and soft guide-wire can be used to sample all lung lobes. If the most affected lung lobe can’t be catheterized with the new technique, a bronchoscopy will be performed to sample the desired lung lobe. 

We anticipate that findings from this study will identify the utility of CT in cats with respiratory tract disease and also develop and safe and practical technique for obtaining lower respiratory tract samples.

Inclusion Criteria:

  • Cats with respiratory disease for whom bronchoalveolar lavage (BAL) is indicated
  • Cats with no general anesthesia contra indications


  • Cost of BAL and chest CT-scan

Samples required:

  • BAL samples
  • Chest CT images



Vicky Sabine (PhD), Clinical Research Coordinator, OVC
Email:; Work Cell #: 226-218-0338

Funded by OVC Pet Trust.

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