(pleuro)pneumonia

• Horses with pleuropneumonia may have a stiff stance and reluctance to move which is associated with pleural pain.
• Pneumonia is an infection of the lower respiratory tract.

  A) bronchopneumonia

  B) pleuropnemonia

  
• Bronchopneumonia = infection in the Bronchi and parenchyma
• Pleuropneumonia has different stages…

  • Exudative stage –sterile transudate increases in the pleural space
  • Fibrinopurulent stage-bacterial invasion and fibrin deposition
  • Organization stage –Fibroblasts grow into exudate (pleural peel)
• Risk factors for pneumonia are…

  • After viral infections
  • Strenuous exercise
  • Transportation and elevation of the head
  • General anaesthesia
  • Overcrowding & inclement weather
  • Dysphagia (predisposes to aspiration)
• There are a variety of causes…

  • Streptococcus equi subsp. Zooepidemicus (this is the most commonly associated pathogen which is a normal commensal in many horses)
  • Staphylococcus aureus and S. pneumoniae (also commonly encountered)
  • Actinobacillus spp (gram negative non-enteric)
  • Escherichia coli, Pasteurella spp, Enterobacter spp, Klebsiella spp and Bordetella bronchiseptica (gram negative bacteria)
  • Bacteroides fragilis (anaerobe)
  • Fusobacterium an Peptostreptococcus anaerobius (anaerobe)
• Clinical signs of pneumonia are…

  • Tachycardia /tachypnoea
  • Respiratory distress
  • Fever
  • Anorexia, depression
  • +/- nasal discharge
  • Exercise intolerance
  • Auscultation is very important
  • A rebreathing bag can help identify these sounds.
• Adventitious lung sounds include…

  • Crackles & wheezes
  • Dull areas
  • Dull area follows flat line
  • This indicates a fluid line which often indicates pleuropneumonia
  • Pleural rubs (pleuropneumonia)
  • Radiation of cardiac sounds when there is consolidation around the heart or fluid in the chest
• Additional signs seen with pleuropneumonia are…

  • Pain in the intercostal spaces
  • Reluctance to walk and possible colic signs
  • Abducted elbows are common
  • Grunting during respiration
  • Abduction of elbows
  • Ventral oedema of the chest
• fill in the blanks

  A) transportation

  B) mucociliary

  C) dysphagia

  D) obstruction

  E) cleft palate

  
• Suspicion is based on physical examination and a rebreathing bag. This can then be followed by…

  • Haematology and biochemistry
  • CBC can indicate the presence of systemic inflammation
  • Neutrophilic leucocytosis
  • Leukopenia (indication of an infectious agent)
  • Anaemia (in chronic cases)
  • Increased fibrinogen and SAA
  • Decreased Fe2+
  • Endoscopy
  • Transtracheal wash (TTW) & BAL
  • Thoracic ultrasonography
  • Radiography
  • Thoracocentesis
  • Thoracoscopy
• with endoscopy, mucous may be identified in the trachea (severe cases of equine asthma or bacterial pneumonia.

  • Sometimes you can identify the infected bronchi
• label the image

  A) percutaneous transtracheal wash

  
• A transtracheal wash is extremely useful in suspected pneumonia cases. The fluid can then be assessed via…

  • Culture & sensitivity (best if percutaneous TTW)
  • Aerobic & anaerobic bacterial culture
  • Anaerobic culture media (do not refrigerate!)
  • Cytology representative of both lungs
  • This should be obtained even if pleural fluid is available for culture!
• ultrasound is beneficial for pathology on the periphery of the lung which is affecting or reaching the pleura. The ultrasound may not reach more internal pathology
• On the left, there is a consolidated lung with a small amount of gas. On the right-hand side, there is a consolidated lung without air in it.

  
• Bronchoalveolar pattern and a collapsed lung on the RHS due to a pneumothorax

   

  A fluid line on the LHS.

  
• what pattern is seen in this image?

  bronchoalveolar

  
• Radiography can help identify more internal pathology of the lungs. When trying to take images of the lungs attempt to remove fluid from the thorax beforehand to get a more clear image of the lungs.
• what is the diagnosis from this image?

  pulmonary abscess

  
• With thoracocentesis, aim to drain with US to avoid the thoracic vein. To perform…

  • Identify 7/8 ICS above costochondral junction
  • Clip, prep aseptically and sedate (local)
  • Perform a stab incision at the cranial edge of the rib
  • Advance drain through incision (pop!)
  • Withdraw trocar, advance blunt tube
  • Secure w/ Chinese finger trap suture (Heimlich valve!)
• Thoracocentesis has diagnostic value (Culture and sensitivity as well as cytology) but also therapeutic value…

  • Drain pro-inflammatory products
  • Removes bacteria
  • Helps to decrease adhesion formation
  • Provides respiratory function improvement
• First line antibiotics are used such as…

  • Penicillin + Gentamycin IV
  • Penicillin + Gentamycin + Metronidazole (aspiration pneumonia) 

  Adjustments are based on culture and sensitivity. Inhaled drugs have been investigated in horses including gentamycin, ceftiofur and cefquinome
• fill in the blanks

  A) jet

  B) ultrasonic

  C) mesh

  
• fill in the blanks

  A) cefquinome

  B) cequinome

  C) saline

  D) gentamicin

  E) ceftiofour

  F) gentamicin

  
• fill in the blanks

  A) jet

  B) ultrasonic

  C) mesh