Back

BREATHING PATTERNS

First broadcast on www.provet.co.uk  

This information is provided by Provet for educational purposes only.

You should seek the advice of your veterinarian if your pet is ill as only he or she can correctly advise on the diagnosis and recommend the treatment that is most appropriate for your pet.

Careful observation of abnormal breathing patterns can provide important information to help the clinician rapidly localise the site of respiratory disease so that appropriate treatment can be started as soon as possible

Key features to note when a patient is presented for a physical examination are :

  • Resting respiratory rate - normal for cats and dogs is 12-18 breaths/minute at rest, but up to 30 breaths/minute if excited 
  • The amount of effort needed by the animal to breath in and out, and during which phase the most effort is required
  • Are chest movements in phase with the breathing cycle - ie the chest wall moves out during inspiration, and in during expiration ?
  • Are the abdominal movements in phase with the breathing cycle (as for chest wall movements) ? During inspiration the abdomen should appear to distend as the contracting diaphragm pushes organs caudally.
  • Is the inspiratory phase the same duration as the expiratory phase or is one longer than the other ?

If respiratory rates are very high the breathing phase may have to be determined from :

  • Flaring of the nostrils
  • Paper/cotton wool movement placed near the external nares
  • Feeling air movement at external nares
  • Auscultation
  • Palpation

Signs of respiratory difficulty include :

  • Mouth breathing - must be differentiated from panting  in dogs (more rapid and the animal has no postural preferences)
  • Flaring of nostrils
  • Neck extension
  • Reluctance to lie down -preference for standing or sternal recumbancy
  • Exaggerated chest wall movements at rest - especially cats
  • Abduction of elbows

Common abnormal respiratory patterns are summarised in the following table :

Signs Cause Comments
Increased respiratory effort - no increased respiratory rate. Prolonged inspiration and expiratory phases. Large airway obstruction May also have audible stridor during prolonged inspiration.

May have high-pitched cough during prolonged expiratory phase
Increased respiratory effort and increased rate Lung and/or pleural disease Obstruction - eg feline asthma - prolonged expiration and increased effort during expiration

Restrictive - eg pulmonary fibrosis - prolonged inspiration and increased effort during inspiration

Both obstructive and restrictive - most lung diseases
Exaggerated abdominal movements Pleural effusion  
Expiratory wheezes on auscultation. Obstructive lung disease  
Crackles on auscultation Restrictive lung disease  
Muffled or no lung sounds on auscultation Pleural effusion, pneumothorax, diaphragmatic rupture with intrathoracic abdominal organs   
Thorax or abdomen move in the opposite direction to that expected during respiratory phases - called paradoxical breathing Diaphragm paralysis or ruptured diaphragm

Flail chest

Intercostal muscle paralysis

Pneumothorax

  
Strong inspiratory effort with loud stertorous sounds. Mouth closed during inspiration. Reverse sneezing Neck usually stretched. Dog is normal after paroxysms
Slow respiratory rate, high tidal volume Airway obstruction  
Prolonged inspiratory phase with increased effort Upper respiratory tract obstruction (eg tumour, stenosis)  
Prolonged expiratory phase with increased effort Lower respiratory tract obstruction (eg bronchitis, emphysema, pleural adhesions)  
Mixed dyspnoea - prolonged, difficult  inspiratory and expiratory phases Severe respiratory diseases eg pneumonia, pneumothorax, hydrothorax  
Rapid shallow breathing Restrictive lung diseases (pneumonia, pleuritis, pleural effusions), rib fractures  
Weakness, reluctance to move and preference to lie in sternal position or stand, abducted elbows (called orthopnoea) Pleural effusion or severe pulmonary disease Slight stress can be fatal in these animals as they have minimal respiratory reserve.
Decreased resonance of chest on percussion Consolidation of lung, pleural effusion, intrathoracic mass or abdominal contents   
Increased resonance of chest on percussion Pneumothorax, emaciation  

 

Last updated : October 2013