TL;DR: Coughing up blood (hemoptysis) is a life-threatening emergency in cats that requires immediate veterinary attention to address potential causes like trauma, heart failure, or toxin exposure.
What is hemoptysis in cats and how can I identify it?
Hemoptysis is the medical term for coughing up blood from the respiratory tract, occurring when there is bleeding in the lungs, windpipe, or airways. The blood may appear as bright red spots, streaks in mucus, or pink frothy foam, and it must be distinguished from hematemesis (vomiting blood) as the causes and treatments differ significantly.
Is it a medical emergency if my cat is coughing up blood?
- Coughing up blood is considered a high-urgency emergency that requires immediate veterinary care.
- Because cats are experts at hiding illness, the presence of blood in a cough usually indicates a severe condition has reached a critical point.
- Potential causes include severe trauma, congestive heart failure, heartworm disease, lung infections, or exposure to anticoagulant toxins like rat poison.
How can a photo of the coughed-up blood help the veterinary team?
- If your cat is stable enough to travel, take a quick photo of the blood or coughed-up material to show the veterinary team.
- The color, consistency, and presence of froth help clinicians determine if the blood is coming from the lungs or the gastrointestinal tract.
- Visual evidence allows the triage nurse to prioritize your cat's care immediately upon your arrival.
Clinical Context (Merck Veterinary Manual)
Coughing up blood (hemoptysis) in cats can be a sign of severe cardiorespiratory compromise, potentially accompanied by dyspnea, tachypnea, cyanosis, collapse, shock, or sudden death. Pulmonary thromboembolism should be considered, and while thoracic radiographs may be normal or show pulmonary infiltrates or hypovascular areas, they may underestimate the degree of clinical respiratory compromise. Cardiogenic arterial thromboembolism, a devastating complication of cardiac disease (such as hypertrophic cardiomyopathy, other cardiomyopathies, hyperthyroidism, or congenital heart disease), can also cause hemoptysis. Heartworm disease, although less common in cats than dogs, can lead to pulmonary arterial thromboembolism resulting in coughing, hemoptysis, and respiratory distress.
Chapter: Cardiology, Pulmonology, Emergency
Source: The Merck Veterinary Manual, 11th Edition (Page 1488)