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Pneumothorax 797

• Thoracic radiographs: changes can lag PEARLS & CONSIDERATIONS having a pet in a closed, unventilated
as much as 48 hours behind clinical Comments bathroom (but not in the bath/shower)
VetBooks.ir • Evaluate (physiologic, hematologic, radio- Bacterial pneumonia should be viewed as a ○ This is often followed by coupage, which Diseases and Disorders
changes.
for 10-15 minutes once to three times
per day while a warm shower runs.
complication of another underlying disease;
graphic exam) patient by 10-14 days after
starting treatment and base decisions to
the chest, performed for 10-30 seconds
Patients should be rigorously evaluated for risk
extend treatment on results of evaluation. B. bronchiseptica infections are an exception. is a series of brusque pats to both sides of
○ Repeating thoracic radiographs approxi- factors if they are not immediately apparent. after each humidification session, with the
mately 1 week after cessation of antibiotics intention of loosening pulmonary secre-
may demonstrate focal primary diseases Technician Tips tions and pus to facilitate expectoration.
(e.g., neoplasia) not evident on initial • Puppies with bacterial pneumonia, par- ○ Pet owners should perform these treat-
radiographs. ticularly those that came from pet stores ments only on the recommendation of a
or shelters, should ideally be isolated from veterinarian; they can make a condition
PROGNOSIS & OUTCOME other animals in the hospital, including cats, worse if used inappropriately.
because B. bronchiseptica is common in those
Varies with severity of disease and nature of animals. SUGGESTED READING
predisposing factors: • For respiratory washes, make sure the wash Lappin MR, et al: Antimicrobial use guidelines for
• Prognosis for uncomplicated pneumonia is solution does not contain bacteriostatic treatment of respiratory tract disease in dogs and
generally good. agents. cats: Antimicrobial Guidelines Working Group of
• Prognosis for animals with risk factors the International Society for Companion Animal
depends on ability to treat/resolve the risk Client Education Infectious Diseases. J Vet Intern Med 31:279, 2017.
factor. • Home treatment may include AUTHOR: Rance K. Sellon, DVM, PhD, DACVIM
○ Recurrent infections are common in ○ Respiratory humidification by inhalation EDITOR: Megan Grobman, DVM, MS, DACVIM
animals with unresolved primary diseases. of cold steam is best accomplished by

Pneumothorax Client Education Bonus Material
Online
Sheet

BASIC INFORMATION • Fracture • Dull or muffled lung sounds (auscultation)
• Asthma in cats ± hyperresonance (percussion)
Definition • Pleural effusion
Accumulation of air within the pleural space Etiology and Pathophysiology
Clinical Presentation • Air may enter the pleural space from damage
Synonym DISEASE FORMS/SUBTYPES to the pulmonary parenchyma (e.g., rupture
Collapsed lung • Traumatic: due to damage to the pulmonary of a pulmonary bleb or bullae, laceration
parenchyma or chest wall of a lung lobe) or damage to the chest
Epidemiology • Spontaneous: due to abnormal pulmonary wall.
SPECIES, AGE, SEX parenchyma without trauma • When the lung parenchyma is normal, small
Young, large-breed male dogs are predisposed • Iatrogenic: due to damage to the lung paren- injuries (e.g., needlestick during centesis) heal
to trauma and subsequent pneumothorax. chyma after thoracocentesis for removal of rapidly.
pleural effusion, aspiration of a pulmonary ○ Intrapleural volumes of air of up to
GENETICS, BREED PREDISPOSITION mass, or thoracic surgery 45 mL/kg cause no clinical signs and take
Northern breeds (Siberian Husky or Alaskan about 2 weeks to resorb spontaneously in
Malamute) are predisposed to spontaneous HISTORY, CHIEF COMPLAINT healthy dogs.
pneumothorax, as are golden retrievers and • Trauma ○ Iatrogenic pneumothorax occurring
possibly Gordon setters and sighthounds. • Acute-onset, tachypnea, respiratory distress, during thoracocentesis is almost invari-
coughing, or restlessness ably associated with chronic effusions
RISK FACTORS • Worsening tachypnea after a medical (especially chylothorax), diseased lung
• Trauma (e.g., hit by car, bite wounds, falls intervention tissue, an uncooperative patient, or an
from elevated heights) inexperienced operator.
• Surgical intervention (e.g., cranial abdominal, PHYSICAL EXAM FINDINGS ○ Iatrogenic pneumothorax may also result
intervertebral disc, pulmonary surgery) • Dyspnea/increased respiratory effort is the from unexpandable lung; in this case, the
• Pleural effusion (e.g., iatrogenic after hallmark finding. pleura has constricted around the lung,
thoracocentesis) ○ Restrictive respiratory pattern: shallow and when pleural effusion is removed, the
• Airway or pulmonary disease (e.g., neoplasia, inspiration. Paradoxical breathing resulting negative pressure results in a tear
parasites) (chest and abdomen move in opposi- of the scarred pleura and subsequent air
tion) sometimes identified. Inspiratory leakage.
GEOGRAPHY AND SEASONALITY distress with stridor suggests upper • Diseased lung or distal airways (e.g., neo-
Trauma is more common in warmer months. airway disease rather than pneumotho- plasia, parasites) can rupture spontaneously,
rax. causing pneumothorax.
ASSOCIATED DISORDERS ○ May be absent in mild cases • Tension pneumothorax is a severe pneu-
• Pulmonary contusions • Other evidence of trauma, blunt (e.g., hit mothorax from any cause that results in
• Diaphragmatic hernia by car) or penetrating (e.g., bite, gunshot, cardiovascular collapse due to inadequate
• Flail chest stabbing) cardiac filling.
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