Smoke Inhalation Poisoning in Dogs

The inhalation of smoke and hot air will lead to a toxicity of great magnitude. The effects can be instantaneous or delayed. Gases such as hydrogen cyanide and carbon monoxide, as well as exposure to soot, heat, and chemicals may lead to severe smoke inhalation poisoning. 

Incidents of smoke inhalation poisoning in dogs are not well recorded. However, available documentation does clearly show that both the upper and lower airways are adversely affected by smoke inhalation. Symptoms are most often severe, especially in the case of a house fire whereby the pet is trapped inside, and may include wheezing, lethargy, and lack of coordination. Depending on factors like the compounds within the smoke and the intensity of exposure, the prognosis for recovery from this type of incident will range from good (slight inhalation promptly treated) to grave (extensive intake of smoke accompanied by burns).

Any type of exposure to smoke should be evaluated by a veterinarian. Soot, asphyxiants, carbon monoxide and products like Teflon coatings on pans left burning all have the potential to inflict airways injury on our pets.

Damage to the upper and lower airways of animals is one of the consequences of smoke inhalation poisoning. Typically this type of event will result due to house fires. Because animals are often frightened and will hide in enclosed spaces, smoke inhalation can often lead to fatality.

Depending on the presence of chemicals, length of smoke exposure, age of pet, obstruction of airways, and other factors, symptoms will vary. Any type of smoke exposure your pet experiences should be evaluated by a veterinarian; subtle changes in your pet’s health may be taking place over hours to days after the event.

• Cough
• Respiratory distress
• Rapid breathing
• Difficulty breathing
• Panting
• High pitched breathing
• Crackling or rattling lung sounds
• Agitation
• Loss of coordination
• Weakness
• Malaise 
• Fever
• Obvious muscle strain when breathing
• Change in bark
• Blistering of mucus membranes
• Redness of mucus membranes
• Eye irritation such as corneal ulceration
• Soot on face
• Odor of smoke on fur
• Loss of consciousness
• Seizures
• Death

Types

Smoke inhalation poisoning is complex. There are chemicals, gases, and particles that will contribute to breathing difficulties, swelling of airways, spasms in the larynx, slow oxygen distribution, and increased lung sounds.

• Chemicals in paper, fabric, plastics, wood
• Ammonia
• Zinc oxide
• Carbon monoxide
• Gases like aldehydes
• Hydrogen cyanide
• Soot particles

The extent of the smoke inhalation will be contingent on several factors. Even though the amount of smoke your pet was exposed to may appear minor, a veterinary visit is needed. Some signs of smoke inhalation damage will not be evident for hours to several days after the event, as the damage works it way through your pet’s body. Some of the factors that can contribute to the condition of your pet over the next week are:

• Duration of exposure
• Whether your pet was in an enclosed space or an open area
• Whether toxic gases that can inhibit oxygen delivery may deprive tissues
• Organ failure may result if tissue damage is severe
• The amount of smoke inhaled will have an effect
• The source of the smoke (house fire, chemical fire, stove top fire) can have a bearing on the injury
• A preexisting lung injury or illness may exacerbate the inhalation experience
• High heat exposure can result in secondary infection
• Pneumonia may be possible
• Changes in blood markers like packed cell volume can appear as long as a week later
• Changes in the lung may take approximately 36 hours to appear

The diagnostic process will take its form dependent on the state of your dog when he arrives at the clinic. Dogs who have experienced severe smoke inhalation complications will be stabilized first and foremost. If your pet was rescued from a house fire situation, he may have received oxygen on the scene. This benefit may greatly impact the prognosis.

 The diagnosis of what took place during an episode of smoke inhalation is not easy to determine, nor is it a rapid procedure. Some of the tests and tools that will be important as the veterinary team assesses your pet will be:

History and Current Symptoms

A recent history of the health of your pet before the event will be important. Pets who have had illnesses that have affected the lungs may suffer more effects or have secondary complications arise. Depending on the symptoms that your dog is experiencing when he is admitted to the hospital, some testing may need to be done right away to assess his chances for recovery. Other diagnostic procedures may be delayed until therapy has had a chance to improve your dog’s condition.

Radiography

Radiographs of the lungs are crucial to the analysis of your canine companion’s state of health. However, changes in the lungs can continue for several days, revealing developments like fibrosis (scarring and thickening of tissue) and edema (fluid build up).

Blood Testing

Various tests for carbon monoxide poisoning, oxygen saturation, hypoxia, and packed cell volume will be needed for continued examination of the effects of the smoke on the body. As with the x-rays, changes may be seen over a period of days necessitating the need for repeat blood testing.

Bronchoscopy/Laryngoscopy

These are excellent tools for examining the extent of the smoke inhalation poisoning. Ulcerations from the heat and charring from soot are two conditions that may be evident.

Numerous other health concerns will be addressed in addition, like brain function and secondary infection due to burns.

Therapy for smoke inhalation poisoning can be extensive. If your dog is symptomatic for smoke inhalation poisoning, the veterinarian will most likely intubate him, performing a tracheostomy. This is done early in the therapy because edema and swelling will often occur, and this way the airway is cleared before the swelling prevents easy intubation. Oxygen is a crucial part of the therapy. Poisonings such as carbon monoxide and cyanide often present with a smoke inhalation event and the oxygen will help to treat them. Oxygen is also critical for reversing or preventing hypoxia (lack of oxygen reaching tissues), which can lead to organ damage and failure.

Medication given as bronchodilators will aid in the reduction of swelling caused by bronchial muscle spasms, and suppress the inflammation that accompanies it. All the while, your dog may be placed under intravenous care if the veterinarian feels fluids will benefit. This is case by case as fluid buildup can occur; however, some pets will need fluid therapy to counteract dehydration that may result. Your pet will be very closely monitored while the intravenous is being administered. Your dog will also be examined carefully in case the skin has been burned. Gentle cleaning and topical medication will be in order.

Sadly, some pets who have experienced smoke inhalation poisoning will be euthanized if the effects of the damage to the lungs, skin, tissues, brain, or organs are irreversible.

Recovery and care can be extensive time-wise as well as financially. Discussion with your veterinarian as to what the prognosis is for your canine companion may be needed. Many pets can survive smoke inhalation poisoning, but may need to be hospitalized for a week or more, especially if respiratory issues begin to develop over the hospitalization period. Tissue damage, burns in the airways, and overwhelming inhalation of chemicals or gases may mean your dog could have a very guarded prognosis.