Introduction

• Cause: trauma (pulmonary contusion Lung: contusion ); coagulopathies, eg warfarin poisoning, thrombocytopenia.
• Signs: respiratory distress varying in degree with extent of hemorrhage; cough (hemoptysis if severe); concurrent traumatic injuries including flail chest; severe blood loss may result in shock.
• Diagnosis: history, clinical signs and physical examination, puse oximetry, radiography, clinicopathologic tests of coagulation and oxygenation.
• Treatment: supportive and symptomatic, manage underlying cause.
• Prognosis: generally good with appropriate management, ultimately depends on underlying cause.

Pathogenesis

Etiology

• Trauma (pulmonary contusion Lung: contusion ).
• Coagulopathy, eg anticoagulant rodenticide poisoning Anticoagulant rodenticide poisoning , thrombocytopenia Thrombocytopenia.
• Neoplasia Lung: pulmonary neoplasia.
• Pulmonary thromboembolism Lung: pulmonary thromboembolism (if severe).
• Parasites (lungworms Angiostrongylosis , lung infarction due to heartworms Canine cardiopulmonary dirofilariasis ).
• Fungal infections (rare).
• Leptospirosis Leptospirosis (hemorrhagic pneumonia pulmonary complication).
• Acute Respiratory Distress Syndrome Acute Respiratory Distress Syndrome (ARDS) or Non-cardiogenic Pulmonary Edema Lung: pulmonary edema (hemorrhagic fluid floods lungs, may be difficult to clinically distinguish from hemorrhage).

Predisposing factors

• Farm dogs - exposure to rodenticides, lungworm paratenic hosts.
• Dogs that are allowed to run free (trauma).

Pathophysiology

• Coagulopathy→ intrapulmonary hemorrhage.
• Metastatic/invasive neoplasia→ invasive destruction of blood vessels → bleeding into lung → hemoptysis and pleural bleeding.
• Pulmonary contusion→ crush and shearing injury to lung capillaries → bleeding.
• Pulmonary infarction→ necrosis of blood vessels.
• ARDS→ severe pulmonary inflammation and capillary vascular leak syndrome.

Timecourse

• Usually acute, variable.

Diagnosis

Treatment

Outcomes