According to Pet Safety Alert, 40,000 pets are killed in household fires yearly and the main cause of death isn't fire itself but asphyxiation. Dogs require quick intervention as smoke affects them more rapidly than in humans.
Dogs exposed to smoke may manifest several smoke-related clues such as fur smelling like smoke, soot around the nose and mouth, singed hair and burns on the skin. However, a lack of evident burns, doesn't necessarily mean a dog is free of smoke-related injuries. When in doubt, it's best to have the dog assessed by a veterinarian as smoke-related injuries can cause serious complications in dogs.
Smoke lowers the oxygen content in the air, which may lead to broncospasms and constriction of the dog's airways. Prolonged exposure, up to the point where no oxygen is left for the dog to breath, can lead to asphyxiation. Dogs who aren't breathing require immediate artificial respiration, and most dogs exposed to smoke require supplemental oxygen. Some dogs improve once exposed to fresh air but may still require veterinarian attention and treatment as smoke-inhalation can turn fatal hours or days later.
Once inhaled, the high temperatures of smoke may cause heat-induced injury to the dog's nasal lining and upper airways. The dog's larynx may swell and spasm leading to a potentially fatal airway obstruction. Treatment in severe cases involves a tracheostomy, a surgery that opens up the airway allowing the dog to breath. Because thermal injury may not become apparent in its earliest stages, it's important not to delay veterinary treatment.
Presumed to be the leading cause of immediate death in smoke-inhalation cases, carbon monoxide binds to red blood cells interfering with oxygen supply to tissues at a cellular level. Starved from oxygen, a dog's organs may fail. Signs of exposure include cherry-colored mucous membranes, agitation, weakness, loss of consciousness and seizures. Oxygen supplementation is needed to remove carbon monoxide as quickly as possible from the dog's system.
Smoke produced from house fires often contains irritating chemicals. The exact nature of these chemicals, their effects and treatments vary depending on the composition of the items burned. Exposure to hydrogen cyanide, released by burned wool, silk, cotton and paper, causes weakness, vomiting, rapid heart rate, arrhythmia, seizures and coma. Treatment for cyanide exposure consists of the intravenous administration of sodium thiosulfate.
Smoke also contains particulate matter that may settle in the dog's upper airways and cause ocular and airway irritation. Additionally, these particulates may act as vehicles facilitating the delivery of toxic gases deep within the dog's airways. The effects of these particles in the dog's respiratory tract vary and treatment is based on their composition and length of exposure. Fortunately, most dogs recover from smoke-related injuries with supportive care, but post-exposure complications, such as bacterial pneumonia, may still occur five to seven days later. Be sure to seek continued veterinary care.