Mortality Associated with Bushfire Smoke Inhalation in a Captive Population of the Smoky Mouse (Pseudomys fumeus), a Threatened Australian Rodent.

A mortality event of nine threatened smoky mice (Pseudomys fumeus) occurred in January 2020 at a captive breeding facility in southeastern Australia that was affected at the time by hazardous levels of bushfire smoke, despite being more than 20 km from the nearest fire. Pathologic and clinical observations indicated smoke inhalation was the cause of death. All animals had significant pulmonary lesions, notably pulmonary edema and congestion, and moderate amounts of dark brown to black pigmented intracellular and extracellular particles from <0.5-2.5 µm in diameter were observed in the central or hilar region of the lungs of four of six animals examined histologically. Deaths occurred between three and 30 d after exposure to smoke and, for seven animals in outdoor acclimatization enclosures, were associated with very high ambient temperature (>40 C). Similar mortalities did not occur in co-located parrots, suggesting differing species sensitivity to smoke inhalation. Our findings highlight the potential for smoke to be an underdiagnosed cause of mortality in free-ranging wildlife during bushfires and for bushfires to affect wildlife populations outside of burnt areas, including in unburnt refugia. Conservation interventions for wildlife after bushfires should consider and, where possible, mitigate the risk of animals dying due to increased respiratory demand following smoke inhalation injury.

Cats with thermal burn injuries from California wildfires show echocardiographic evidence of myocardial thickening and intracardiac thrombi.

Recent increases in the prevalence and severity of wildfires in some regions have resulted in an increased frequency of veterinary burn patients. Few studies exist regarding diagnostics and management of burn wounds in veterinary patients and current knowledge is extrapolated from human literature and research models. Post-burn cardiac injury is a common finding and predictor of mortality in human patients and echocardiography is an important tool in monitoring response to therapy and predicting outcome. We describe the notable findings from cats naturally exposed to California wildfires in 2017 and 2018. Domestic cats (n = 51) sustaining burn injuries from the Tubbs (2017) and Camp (2018) wildfires were prospectively enrolled and serial echocardiograms and cardiac troponin I evaluations were performed. Echocardiograms of affected cats revealed a high prevalence of myocardial thickening (18/51) and spontaneous echocardiographic contrast and thrombi formation (16/51). Forty-two cats survived to discharge and 6 died or were euthanized due to a possible cardiac cause. For the first time, we describe cardiovascular and coagulation effects of thermal burn and smoke inhalation in cats. Further studies in veterinary burn victims are warranted and serve as a translational research opportunity for uncovering novel disease mechanisms and therapies.

Successful treatment of canine acute respiratory distress syndrome secondary to inhalant toxin exposure.

OBJECTIVE: To describe the successful management of a dog with acute respiratory distress syndrome secondary to inhalant toxin exposure. CASE SUMMARY: An 8-year-old male neutered Greyhound was referred with severe respiratory distress 56 hours after exposure to an aerosol toxicant. The patient developed respiratory difficulties requiring veterinary attention within 12 hours of initial exposure. Treatment at the referral hospital included mechanical ventilation and supportive care. The patient was discharged 5 days after admission to the referral hospital. NEW OR UNIQUE INFORMATION: This is the first report, to the authors' knowledge, of canine acute respiratory distress syndrome secondary to inhalant toxin exposure not associated with smoke inhalation. The report summarizes the provided care and subsequent successful outcome.

Systemic and Local Management of Burn Wounds.

Management of severe burn injury (SBI) requires prompt, complex, and aggressive care. Despite major advances in the management of SBI-including patient-targeted resuscitation, management of inhalation injuries, specific nutritional support, enhanced wound therapy, and infection control-the consequences of SBI often result in complex, multiorgan metabolic changes. Consensus guidelines and clinical evidence regarding specific management of small animal burn patients are lacking. This article aims to review updated therapeutic consideration for the systemic and local management of SBI that are proven effective to optimize outcomes in human burn patients and may translate to small animal patients.

[Smoke inhalation in dogs and cats - a retrospective study over 5.5 years]. / Rauchvergiftungen bei Hunden und Katzen - eine retrospektive Studie über 5,5 Jahre.

OBJECTIVE: Particularly during household fires, inhalation of hot air and smoke, and the formation of carboxyhaemoglobin and cyanide lead to respiratory tract and lung injury in small animals. Additionally, oxygenation is impaired in most cases. The aim of this retrospective study was to analyse smoke exposure, physical examination findings and clinical pathology results as well as their course in dogs and cats presented after smoke inhalation. MATERIAL AND METHODS: Patient histories of dogs and cats that had been diagnosed with smoke inhalation between January 1, 2008 and August 31, 2013 were analysed retrospectively. Normality was tested using the Shapiro-Wilk test and analyses were performed using t-tests, the Chi-square test and Mann-Whitney U-test. P-values < 0.05 were considered significant. RESULTS: The analysis included data of 13 cats and nine dogs. The animals were presented within 12 hours after a household fire with sooting, coughing and polypnoea. Pretreatment in approximately 50% of patients consisted of oxygen, corticoids and bronchodilators. The most common clinical abnormalities were tachycardia, polypnoea and hypothermia as well as pink mucous membranes. Changes observed from clinical pathology analysis included the haemoconcentration, reticulocytosis, a left shift of the leucogram, mixed acid-base disorders and moderate carboxyhaemoglobinema. Therapy included oxygen and fluid therapy, antibiotic treatment, corticoids, bronchodilators and cleaning of the animal. One cat died and 21 animals were discharged 0-6 days after presentation. CLINICAL RELEVANCE: Dogs and cats suffering from smoke inhalation were presented with respiratory disorders and dehydration. Outcome is good if the animals are treated early and adequately with oxygen and fluid therapy.

Toxic smoke inhalation in fire victim dogs.

Fifteen dogs were found dead in a house that was on fire. Several of these dogs were partially burned. Four dogs were submitted for postmortem examination, 2 of which were determined to have died prior to the fire. Of the 2 submitted fire fatalities, only 1 dog had burns on its body (dorsum and right side of body). Internally, both dogs had soot deposits mixed with mucus in the larynx, trachea, and primary bronchi. Microscopically, soot was identified within both airways and alveolar spaces. There were no macroscopic or microscopic indications of vital heat exposure. High levels of carboxyhemoglobin were detected in the 2 dogs tested. The findings in this case support the use of postmortem examination and toxicology testing to allow for determination of vital reaction to heat and fire fumes.

Successful outcome in a dog with neurological and respiratory signs following smoke inhalation.

OBJECTIVE: To report the case management of a patient with smoke inhalation complicated by neurological impairment, carboxyhemoglobinemia, acute respiratory distress syndrome (ARDS), upper airway obstruction, aspiration pneumonia, and bacteremia. CASE SUMMARY: A 1.5-year-old male intact Beagle presented shortly after being involved in a household fire. Upon arrival the dog was diagnosed with ARDS and demonstrated acute neurological signs (eg, obtundation and seizures). Treatment included mechanical ventilation, temporary tracheostomy, and intensive supportive care. During hospitalization, the dog suffered multiple complications including prolonged neurological abnormalities, aspiration pneumonia, and bacteremia. The dog recovered over a 16-day period. NEW OR UNIQUE INFORMATION PROVIDED: This is the first description of extensive management of a patient suffering both neurological and respiratory complication due to smoke inhalation, and details the steps that were taken to achieve a successful outcome.

Severe burn injury, burn shock, and smoke inhalation injury in small animals. Part 1: burn classification and pathophysiology.

OBJECTIVE: To review the literature related to severe burn injury (SBI), burn shock, and smoke inhalation injury in domestic animals. Current animal- and human-based research and literature were evaluated to provide an overview of thermal burn classification and the pathophysiology of burn shock and smoke inhalation injury. ETIOLOGY: Severe burn injury, burn shock, and smoke inhalation injury may be encountered as a result of thermal injury, radiation injury, chemical injury, or electrical injury. DIAGNOSIS: Burns can be subdivided based on the amount of total body surface area (TBSA) involved and the depth of the burn. Local burn injuries involve <20% of the TBSA whereas SBI involves >20-30% of the TBSA. The modern burn classification system classifies burns by increasing depth: superficial, superficial partial-thickness, deep partial-thickness, and full-thickness. SUMMARY: Local burn injury rarely leads to systemic illness whereas SBI leads to significant metabolic derangements that require immediate and intensive management. SBI results in a unique derangement of cardiovascular dysfunction known as "burn shock." The physiologic changes that occur with SBI can be divided into 2 distinct phases; the resuscitation phase and the hyperdynamic hypermetabolic phase. The resuscitation phase occurs immediately following SBI and lasts for approximately 24-72 hours. This period of hemodynamic instability is characterized by the release of inflammatory mediators, increased vascular permeability, reduced cardiac output, and edema formation. The hyperdynamic hypermetabolic phase begins approximately 3-5 days after injury. This phase is characterized by hyperdynamic circulation and an increased metabolic rate that can persist up to 24 months post burn injury in people.

Severe burn injury, burn shock, and smoke inhalation injury in small animals. Part 2: diagnosis, therapy, complications, and prognosis.

OBJECTIVE: To review the evaluation and treatment of patients suffering from severe burn injury (SBI), burn shock, and smoke inhalation injury. Potential complications and prognosis associated with SBI are also discussed. DIAGNOSIS: Diagnosis of burn injury and burn shock is based on patient history and clinical presentation. Superficial burn wounds may not be readily apparent for the first 48 h whereas more severe wounds will be evident at presentation. Patients are diagnosed with local or SBI by estimating total body surface area involved using the 'Rule of Nines' or the Lund-Browder chart adapted from the human literature. THERAPY: Patients suffering from SBI require immediate and aggressive fluid therapy. Burn wounds require prompt cooling to prevent progressive tissue damage. Due to significant pain associated with burn wounds and therapeutic procedures, multimodal analgesia is recommended. Daily wound management including hydrotherapy, topical medications, and early wound excision and grafting is necessary with SBI. COMPLICATIONS: There are numerous complications associated with SBI. The most common complications include infections, hypothermia, intra-abdominal hypertension, and abdominal compartment syndrome. PROGNOSIS: The prognosis of SBI in domestic animals is unknown. Based on information derived from human literature, patients with SBI and concomitant smoke inhalation likely have a worse prognosis than those with SBI or smoke inhalation alone.

The association of physical examination abnormalities and carboxyhemoglobin concentrations in 21 dogs trapped in a kennel fire.

OBJECTIVE: To evaluate physical examination findings and their association with carboxyhemoglobin (COHb) concentrations in 21 dogs that were exposed to smoke during a kennel fire. SERIES SUMMARY: Twenty-one dogs were exposed to a kennel fire. Physical exam findings, presenting, and posttherapy COHb concentrations as well as therapeutic interventions were evaluated. COHb concentrations upon presentation were increased in all smoke inhalation exposed dogs. These dogs were compared to a small set of clinically normal staff-owned dogs who were not exposed to fire. Physical parameters significantly associated with higher COHb concentrations included lower body temperature, increased respiratory effort, abnormal respiratory auscultation, altered neurologic status, and length of hospital stay. Oxygen therapy resulted in a more rapid decline in COHb concentrations although 5 dogs still had mildly increased COHb concentrations 24-hour postadmission. UNIQUE INFORMATION PROVIDED: This study describes the relationship of admitting clinical findings of dogs exposed to a kennel fire with their initial blood COHb concentrations. It also describes the resolution of increased COHb concentrations with use of oxygen therapy and hospitalization. Additionally, COHb concentrations for a control group of dogs was evaluated and compared to the dogs exposed to smoke inhalation.

Leukoencephalomalacia and laminar neuronal necrosis following smoke inhalation in a dog.

Acute respiratory and neurologic disease after smoke inhalation are well documented, but human patients may also develop delayed-onset neurologic symptoms associated with leukoencephalomalacia after exposure to smoke or carbon monoxide. In this case, a dog developed progressive neurologic signs 6 days after rescue from an apartment fire. At necropsy 9 days after smoke inhalation, leukoencephalomalacia of the central cerebral white matter was accompanied by laminar necrosis of cerebrocortical neurons. This is the first report of delayed posthypoxic leukoencephalopathy in a nonhuman animal.

Clinical and neuropathological findings of acute carbon monoxide toxicity in chihuahuas following smoke inhalation.

Three adult Chihuahuas were presented for evaluation after smoke inhalation during a house fire. All three dogs received supportive care and supplemental oxygen. After initial improvement, the dogs developed seizures. Despite anticonvulsant therapy and supportive care, the dogs died. The brains of two dogs were examined. Lesions were identified that were compatible with acute carbon monoxide (CO) toxicity. Lesions were confined to the caudate nucleus, the globus pallidus, and the substantia nigra bilaterally, as well as the cerebellum, cerebral cortex, and dorsal thalamus. This case report describes the clinicopathological sequelae in acute CO toxicity.

Recurrent smoke-induced respiratory infections in a ruby blue-headed pionus parrot (Pionus menstruus rubrigularis).

A 4-year-old female blue-headed pionus parrot (Pionus menstruus rubrigularis) presented repeatedly for acute smoke inhalation. The protracted clinical course and secondary respiratory infections with multiple pathogens represented characteristic sequelae to smoke inhalation and toxicosis seen in other species, but these have not been previously reported in birds.

Fire and smoke inhalation injury in horses.

Although not common in horses, fire and smoke inhalation trauma may require veterinary assistance at several levels. Most commonly, the equine clinician is called on to provide care of potentially complex and emotionally charged cases. Thermal injury, along with smoke inhalation, can cause local and diffuse lesions. Massive tissue edema may occur, which can be a challenge to manage as well as creating organ dysfunction at distant sites. Further complications of severely affected patients are varied and include life-threatening sepsis. This article reviews some of the important features of this type of trauma.

Smoke inhalation.

Unfortunately, fires are common events both in urban and rural portions of the United States. Smoke inhalation is the leading fire-related cause of death. The elemental combustion products of fire are light, heat, and smoke. Smoke is a very complex mixture of potentially harmful substances. Although a relatively rare presenting event to small animal hospitals, when animal fire victims do appear, clinicians must know how to recognize the signs of smoke inhalation and how to successfully deal with them. This discussion will investigate the toxic nature of fire smoke, its mechanism of action upon respiratory tissues, the clinical signs displayed, and its diagnosis and treatment. Differential diagnoses of smoke inhalation and prevention and prognosis will also be explored. Veterinary hospitals should have set protocols in place for managing animal victims of smoke inhalation in order to ensure a successful outcome.

Smoke exposure in cats: 22 cases (1986-1997).

OBJECTIVE: To review clinical findings and clinical course for cats exposed to smoke in residential fires and to determine clinical variables that may have prognostic importance. DESIGN: Retrospective study. ANIMALS: 22 cats admitted to our veterinary teaching hospital between 1986 and 1997 with a history of smoke exposure during a residential fire. PROCEDURE: Medical records were reviewed for history, clinical signs, physical examination findings, changes in respiratory tract signs, initial hematologic analysis, treatment, results of thoracic radiography, and outcome. RESULTS: Fifteen of 22 (68%) cats were categorized in the uncomplicated group, 5 (23%) in the complicated group, and 2 (9%) were discharged after a short period because of financial considerations. Twenty (91%) cats survived, but 2 (9%) were euthanatized because of severe respiratory compromise or neurologic changes. Predominant thoracic radiographic changes were diffuse interstitial pattern (6 cats) and focal alveolar pattern (5). The majority (8/13) of cats that were stable or had improved by the day after admission had an uncomplicated clinical course while hospitalized, whereas cats that were worse on the day after admission tended to have a complicated clinical course. CONCLUSIONS AND CLINICAL RELEVANCE: Cats that survive a residential fire and are admitted to a hospital have a good chance to be discharged. Cats that do not have signs of respiratory tract dysfunction at admission probably will not develop severe respiratory complications. For cats with signs of respiratory dysfunction at admission, better prognostic information will be determined by monitoring progression of the respiratory condition on the day after admission.

Smoke exposure in dogs: 27 cases (1988-1997).

OBJECTIVE: To evaluate clinical findings, prognostic variables, and clinical course of dogs exposed to smoke. DESIGN: Retrospective study. ANIMALS: 27 dogs exposed to smoke in residential fires. PROCEDURE: Medical records were reviewed for 1988-1997. Time of year, signalment, interval from fire to arrival at veterinary hospital, duration of smoke exposure, clinical signs at the fire scene, physical examination findings, changes in respiratory tract signs, radiographic findings, hematologic and arterial blood gas analyses, initial treatment, clinical course, and outcome were recorded. RESULTS: 27 dogs (16 uncomplicated and 11 complicated cases) were identified. In the complicated group, 4 dogs died, 4 were euthanatized, and 3 had a complicated clinical course. Stupor or coma (8 of 17 dogs), coughing or gagging (6), and respiratory difficulty (6) were commonly observed at the fire scene. Substantial improvement was evident within 5 to 30 minutes after dogs were given supplemental oxygen at the fire scene. More severely affected dogs had a higher median PCV (58%) than less severely affected dogs (50%). Most common thoracic radiographic findings were an alveolar (10 dogs) or an interstitial (3) pattern. CONCLUSIONS AND CLINICAL RELEVANCE: Dogs exposed to smoke can develop respiratory or neurologic complications. Monitoring progression of respiratory problems on the day after the fire may provide clinicians with clues about the severity of each dog's condition.