Feline Breathing Disorders Explained by Specialists

• Nasopharyngeal polyps
  – Benign growths that can lead to noisy breathing, stertor, reduced airflow and, in more severe cases, open-mouth breathing.
  – They can also cause difficulty swallowing or a change in voice.
  – Usually diagnosed through an oral exam, imaging or endoscopy.
• Laryngeal disease
  – Impaired movement of the arytenoids resulting in voice change, increased effort and stridor.
  – Cats are at risk of acute decompensation, as minor increases in obstruction can cause sudden breathing difficulty.
  – Sedation or anaesthesia will be required for a full assessment and diagnosis.
• Brachycephalic airway issues
  – Features such as an elongated soft palate, narrow nostrils and everted saccules reduce the space available for airflow and make breathing noisier and more effortful.
  – The narrowed airway can cause persistent breathing effort and characteristic upper-airway noise.
  – Heat and stress increase airway demand and can make breathing noticeably more difficult.

Lower airway disorders

Diseases affecting the lower airways tend to interfere with airflow movement rather than airflow entry.. Cats may exhibit increased effort, wheeze, or episodic distress. Examples include:

• Feline asthma
  – Often presents as increased expiratory effort, wheeze and episodic distress. Note, coughing may or may not be present.
  – Imaging findings typically vary, and changes can be subtle or inconsistent.
  – Most cats respond to bronchodilators and corticosteroids.
• Chronic bronchitis
  – This is a long-term inflammatory condition of the lower airways.
  – A chronic cough is common and can become more noticeable with exertion.
  – Clinical signs can resemble asthma, and some cases show features of both.

Pleural space disorders

Fluid or air around the lungs reduces the lungs ability to inflate and expand. Cats with these disorders can appear distressed even at rest. Some examples include:

• Pleural effusion
  – Fluid builds up around the lungs and prevents them from expanding fully.
  – Cats often experience rapid, shallow breathing but may only have vague signs at first.
  – The causes vary and can include heart disease, neoplasia, infection or trauma.
• Pyothorax
  – There is purulent (pus) fluid in the chest, usually due to a bacterial infection.
  – Affected cats are typically unwell, with fever, lethargy and noticeable breathing difficulty.
  – Management involves draining the chest and using appropriate antimicrobial treatment.
• Chylothorax
  – A milky bodily fluid (chyle) accumulates in the pleural space.
  – Breathing effort tends to increase over time, and some cats lose weight.
  – The response to drainage or dietary changes varies, and the cause may be cardiac or idiopathic (unknown).
• Pneumothorax
  – This occurs when air enters the pleural space and collapses part or all of a lung.
  – Signs usually appear suddenly, with significant breathing distress or open-mouth breathing.
  – The causes of pneumothorax include trauma, cancer or spontaneous rupture, and stabilisation and chest drainage are required.

Pulmonary parenchymal disorders

When the lung parenchyma is involved, oxygen exchange becomes compromised, and the breathing pattern reflects this strain. Condition examples include:

• Pneumonia
  – Can be caused by infection or by material entering the lungs during aspiration.
  – Cats may have fever, cough or increased breathing effort, though signs and symptoms vary.
  – Imaging findings depend on which areas of the lung are involved.
• Neoplasia (cancer)
  – May arise in the lungs or spread there from another site.
  – Breathing often becomes progressively faster or more strained, and weight loss is common.
  – Imaging helps define the location and appearance of any masses
• Pulmonary contusions
  – Usually, this is the result of trauma and involves bruising within the lung tissue.
  – Cats can have sudden breathing difficulty even when there are no external injuries.
  – The severity depends on how much of the lung is affected.

Breathing changes aren’t always respiratory in origin. Heart disease, anaemia, metabolic problems and pain can all influence how a cat breathes, and these can resemble primary respiratory disorders despite having different causes.