Smoke Inhalation in Cats

Smoke inhalation in cats occurs when an airborne chemical or gas released by burning is breathed in. Household fires are the most common cause of smoke inhalation in cats, as felines often hide during a fire rather than trying to escape. Smoke inhalation could cause secondary pneumonia, neurologic dysfunction, and impaired delivery of oxygen, as well as irritation to the mucous membranes. The chemical gases released during a fire could also cause poisoning in the feline. Gases such as hydrogen cyanide and carbon monoxide bind with oxygen molecules, allowing the poison to circulate through the blood. If your cat has inhaled smoke and begins displaying signs of smoke inhalation such as coughing, it is crucial to seek the attention of a veterinary professional. 

Smoke inhalation in cats can cause secondary pneumonia, neurologic dysfunction, impaired delivery of oxygen and irritation to the mucous membranes. A feline may clue a pet owner into these conditions through coughing, difficulty breathing, and an increased respiratory rate. Symptoms of smoke inhalation a cat owner should watch for include: 

• Open-mouthed breathing
• Increased respiratory rate 
• Difficulty breathing 
• Cough 
• Squinting of the eyes
• Watery eyes
• Burns on the skin or eyes
• Swelling of the nose or mouth
• Inflammation of the mouth or nose
• Vocalization
• Foaming at the mouth
• Weakness 
• Seizure 
• Coma 

House fires commonly release gases of hydrogen cyanide and carbon monoxide. Hydrogen cyanide is released in the air when carbon containing materials such as plastics, nylon, paper, cotton, and wool are being burned. Carbon monoxide is a gas produced by organic matter combustion and is often undetected. The type of smoke or gases inhaled depends on the element that is being burned, and could include: 

• Titanium tetrachloride
• Sulfur trioxide
• Phosphorus
• Zinc oxide
• Oxide of nitrogen
• Methane
• Nitrogen
• Cyanide gas
• Carbon monoxide
• Soot

The veterinarian will begin the diagnosis of smoke inhalation by reviewing your cat’s medical history and performing a physical examination. During the physical examination, the veterinarian will search for any evidence of burns and injury to the respiratory organs. It is important to share any information about the fire that has occurred so the veterinarian has an idea of what type of smoke the cat may have inhaled. The veterinarian may use additional diagnostic tools to diagnose smoke inhalation. 

Bronchoscopy/ Laryngoscopy

An examination of the throat and lungs using a flexible camera will allow the veterinarian to find mucosal ulcerations, edema. Soot deposits, charring, erythema and subglottic injury. 

Pulse Oximetry 

A test used to measure the blood oxygen levels. This test will evaluate how much oxygen the cat is receiving from her lungs to her heart, into the blood.

Blood Carboxyhemoglobin Test

A test that measures the carbon monoxide inhaled using a blood sample. 

Metabolic Acidosis & Lactate Measurement

High levels of lactate and metabolic acidosis in the blood can aid in pinpointing the type of gas inhaled by the cat. 

Imaging

Pulmonary radiographs can be taken approximately 24-36 hours after exposure to exhibit any injury to the lungs, heart and respiratory organs. A CT scan may also be taken to address cerebral hypoxia and injury to the globus pallidus, which would indicate carbon monoxide poisoning. 

Cats that have experienced smoke inhalation will receive supplemental oxygen for at least six hours, despite respiratory improvement. An oxygen rich environment will prevent chemicals from binding with oxygen molecules and circulating in the blood. Supplementary oxygen can be given through an oxygen tube, mask or oxygen chamber. A bronchodilator may be given to the feline to open up the airways and reduce bronchospasms. An intravenous fluid may be given to the feline, but only in small amounts as excessive fluid therapy could cause pulmonary parenchymal damage. The veterinarian will prescribe additional treatments based on physical injury of the eyes, nose, mouth, lungs and respiratory system.

Recovery of smoke inhalation in cats depends greatly on the type of smoke that was inhaled, how long the cat stayed in the smoke, and how quickly medical attention was received. Most cats presented to the veterinarian with smoke inhalation will recover with supportive care, however, the feline could stay in hospitalization from 48 hours to two weeks. Once the feline is allowed to return home, pet owners will likely be asked to add an air filter the home to avoid stressing the feline’s respiratory system. Physical activities will also be kept at a minimum for a number of days to give the lungs and heart time to heal. Your doctor will ask you to follow-up with him just a few weeks after returning home to ensure no permanent damage has been done and the feline is making a full recovery.