Page 466 - WSAVA2018
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 25-28 September, 2018 | Singapore
E. Robertson1
1American Board Certified Diplomate Feline Practice, Feline Vet and Endoscopy Vet Referrals, Brighton, East Sussex, United Kingdom
Laryngoscopy, tracheoscopy and
bronchoscopy (the last two collectively called ‘tracheobronchoscopy’) are considered valuable procedures for investigating causes of feline lower airway disease. Airway endoscopy is indicated in those patients presenting with stridor, dysphonia, acute or chronic cough, inspiratory or expiratory dyspnea, haemoptysis, and/or unexplained radiographic infilltrates (focal, diffuse, lobar, bronchial, alveolar or consolidation) which have not been diagnosed by other means.1-4
Despite the potential risks associated with lower airway endoscopy, it can be performed safely in the vast majority of cases. When performed in favourable and controlled conditions, tracheobronchoscopy can still be considered a relatively safe and reliable procedure for the diagnosis, the treatment of respiratory tract disease (e.g. removal of tracheal foreign body) and suction of freshly aspirated materials.4
always be incorporated as a routine part of any upper or lower airway endoscopic examination. The differentiation between laryngeal problems and lower airway disease based solely on history and clinical examination is not always obvious in cats. Laryngeal disorders can induce some coughing, but as soon as the laryngeal inlet is reduced, the main signs are dyspnoea and stridor. In cats, the most common laryngeal disorder is laryngeal oedema; tumours and paralysis are less common.4 Tracheoscopy is rarely performed on its own as such; however, when performing tracheobronchoscopy the trachea will always be investigated as part of a lower airway endoscopic examination. Tracheoscopy alone would be indicated when a tracheal disorder is suspected based on clinical signs and confirmed on imaging. When tracheal compression or displacement is shown to be due to the presence of an extra- or intrathoracic mass, especially with a mediastinal space-occuying lesion/mass, endoscopy would not be helpful for the diagnosis nor choice of treatment.
Bronchoscopy should be considered in those cases of suspected (or confirmed) lesions of the mainstem bronchi, segmental bronchioles/airways (e.g FB, neoplasia) and/or for visually-guided intervention and airway sampling. Severe cardiac arrhythmia, heart failure or severe hypoxia are contraindications to tracheobronchoscopy.
Patient preparation and anaesthesia
Prior to proceeding with tracheobronchoscopy, the endoscopist should be well versed in normal anatomy and appearance of the feline airways as this will allow for rapid and efficient evaluation, and collection of samples.5 The rapidity of the procedure when performed by an experienced endoscopist is one of the key factors in a successful outcome. Lower airway endoscopy requires general anaesthesia and is, therefore, considered medium- to-high risk in many feline respiratory cases due to the relatively small and higher airway responsiveness of the cat compared to that of the dog. Moreover, as soon as a cat presents as a dyspnoeic patient, the procedure is considered even more of a potential risk of acute respiratory embarrassment during induction, maintenance and recovery phases of general anaesthesia.
For cats, a small diameter (e.g. 3–4 mm), fexible
  It’s prudent for the feline practitioner to appreciate that lower airway endoscopy should not be considered to be the first ancillary procedure in these patients. Rather, the suspicion of diseases and the real need for endoscopy to reach the proper diagnosis should only be performed after collecting a full clinical history and performing a full clinical examination, including response to previous treatments (antibiotics, anthelmintics, bronchodilators, etc.). Further tests could include haematology, biochemistry, D. immitis Ab/Ag testing, faecal parasitology and thoracic radiographs. Lower airway endoscopy may then become irrelevant, when radiographic findings include the presence of metastases, mediastinal mass, suspicion of cardiac diseases, pleural disease or diaphragmatic hernia. Laryngeal examination is indicated for cats presenting with airway signs such as dysphonia, stridor or inspiratory/expiratory dyspnoea. Laryngoscopy can be performed easily and should

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