A1-year-old 1.6-kg (3.52-lb) spayed female Toy Poodle (dog 1) was evaluated (day 1) because of vomiting and lethargy, the onset of which was attributed by the owners to dietary indiscretion. The owners reported that the dog had eaten half of an egg and 1 to 2 oz of cheese. Physical examination revealed mild dehydration, tachypnea (respiratory rate, 40 breaths/min; reference range, 18 to 34 breaths/min), and signs of abdominal pain. Initial diagnostic procedures revealed no abnormalities in venous blood gas variables; PCV; and plasma electrolytes, plasma total solids, and blood glucose concentrations. Oxygen saturation determined via pulse oximetry while the dog was breathing room air was 96%, and systolic blood pressure (determined indirectly by use of a Doppler blood pressure monitor) was 140 mm Hg. Tachypnea was attributed to abdominal pain. Results of serum biochemical analyses indicated mildly high alkaline phosphatase (159 U/L; reference range, 10 to 150 U/L) and alanine aminotransferase (97 U/L; reference range, 5 to 60 U/L) activities; results of a CBC were within reference limits. Although abdominal radiography revealed decreased detail in the right cranial quadrant, no evidence of pancreatitis or other cause for the gastrointestinal tract signs was identified ultrasonographically. No vomiting occurred throughout the period of hospitalization. Initial treatments included IV administration of isotonic crystalloid solution (120 mL/kg/d [54.5 mL/lb/d]) and buprenorphine^a (0.01 mg/kg [0.005 mg/lb], IV, q 8 h). Food and water were withheld.

On the second day of hospitalization, the dog became acutely dyspneic; its respiratory rate was 80 breaths/min, and the SpO₂ value while the dog was breathing room air was 78%. The dog was transferred to an intensive care unit and placed in an oxygen cage (FIO₂, 0.4), after which the SpO₂ improved to 94%. An arterial blood gas analysis was not pursued because of the small physical size and unstable clinical state of the dog. Thoracic radiography revealed a diffuse interstitial pulmonary pattern; no abnormalities in the size of the heart or in the pulmonary vasculature were detected. Primary differentials considered included pulmonary edema (cardiogenic and noncardiogenic) and early aspiration pneumonia. The dog had no clinical signs suggestive of volume overload (ie, weight gain or interstitial edema), and central venous pressure was 0 cm H₂O. Other differentials, including pulmonary eosinophilic infiltrates, lymphocytic interstitial pneumonitis, pulmonary thromboembolism, hemorrhage, and idiopathic pulmonary interstitial fibrosis, were considered less likely and were not pursued diagnostically. Aminophylline^b was administered (10 mg/kg [4.5 mg/lb], IM, q 8 h) in an attempt to improve the dog's comfort. On auscultation, airway sounds were harsh, but no wheezes were detected. Because of the development of moderate hypokalemia (2.66 mmol/L; reference range, 3.5 to 5.3 mmol/L), oral and IV potassium supplementation were initiated. To address possible development of vasculitis, the crystalloid IV infusion was discontinued and hetastarch was administered (20 mL/kg/d [9.1 mL/lb/d], IV) in an attempt to limit fluid extravasation.

Because no vomiting had occurred and anorexia continued, a nasoesophageal tube was placed for provision of liquid enteral nutrition^c on the third day of hospitalization. In the morning, the dog was consistently well oxygenated (SpO₂, 99%) at an FIO₂ of 0.4 and had a respiratory rate of 44 breaths/min; however, the dog remained oxygen dependent. Throughout the day, the respiratory rate increased to a maximum rate of 120 breaths/min. Serial analyses of venous blood gases revealed a progressive respiratory acidosis, and the central-venous partial pressure of carbon dioxide ranged from 54.9 mm Hg (reference range, 35 to 45 mm Hg) on day 3 to a peak of 60 mm Hg on day 5 of hospitalization. The respiratory rate and respiratory effort began to gradually improve after day 3, despite worsening respiratory acidosis. The acidosis did not resolve until day 7 of hospitalization (venous partial pressure of carbon dioxide, 44.5 mm Hg), at which time the dog was also able to maintain normoxemia while breathing room air.

Further discussion with the owner revealed that the dog had been exposed to a commercial hydrocarbon waterproofing spray^d 24 hours before the development of clinical signs. Two other dogs in the household each had 1 bout of vomiting after that exposure but did not require medical attention. The owner reported using approximately 75% of a bottle of the spray to waterproof 4 pairs of shoes in her bathroom. During the procedure, the bathroom window was open; however, the door was not completely closed, and the dog had access to the room after the spraying was completed. The owner reported that the spray did not have an odor but that she felt dizzy after using it.

For dog 1, additional diagnostic procedures were considered, such as an endotracheal wash or bronchoscopy with BAL and helical computed tomography. These procedures were not pursued because of the severity of respiratory compromise and the risks associated with anesthesia and invasive procedures. Furthermore, these diagnostic procedures were unlikely to change the course of treatment in a dog affected by toxin inhalation. Supportive care was continued with administration of oxygen, bronchodilators, IV crystalloid and colloid therapy, and enteral nutritional supplementation. Administration of antimicrobials was withheld because sterile inflammation or pneumonitis was the working diagnosis.

On day 4 of hospitalization, the dog was able to sustain a 3-hour period without provision of supplemental oxygen before becoming dyspneic. Radiography revealed that the pulmonary pattern was unchanged. Because of minimal improvement by the end of the fourth day, treatments with albuterol^e (90 μg, q 12 h) and fluticasone^f (110 μg, q 12 h) administered via inhalation through a spacer device and face mask adapter^g were initiated. Clinicopathologic analyses were repeated on the fifth day and revealed mild panhypoproteinemia (albumin, 2.4 g/dL [reference range, 2.7 to 4.4 g/dL]; globulin, 1.6 g/dL [reference range, 2.2 to 4.2 g/dL]). Serum alkaline phosphatase and alanine aminotransferase activities were within reference ranges, and no abnormalities were detected via a CBC.

By day 7, the dog's respiratory rate had decreased to 38 breaths/min and the SpO₂ value was 96% while the dog was breathing room air. Thoracic radiographic findings were unchanged. Oxygen supplementation was discontinued. On the eighth day, the nasoesophageal tube was removed because the dog's appetite returned. The dog was discharged 8 days after the initial evaluation, and the owner was instructed to administer aminophylline (10 mg/kg, PO, q 8 h) and fluticasone (110 μg, q 12 h) and albuterol (90 μg, as needed) via inhalation. Aminophylline treatment was discontinued after 2 weeks, and the fluticasone treatment was discontinued after 1 month. One year later, the dog had no clinical signs and was not receiving any medication.

A 10-month-old 1.7-kg (3.74-lb) sexually intact female Chihuahua (dog 2) was examined because of acute respiratory distress, vomiting, and anorexia. These clinical signs had developed approximately 18 hours after exposure to a waterproofing spray containing heptane, a highly flammable liquid hydrocarbon. The owner had used an entire bottle of waterproofing spray on a couch inside a small apartment when the dog was present in the same room. A person in the household also required medical attention for respiratory distress after exposure to the spray.

On the day of evaluation, dog 2 had become increasingly lethargic and tachypneic (respiratory rate, 70 breaths/min) but maintained normoxemia (SpO₂, 98% [while dog was breathing room air]). Initially, thoracic radiography revealed a moderate interstitial pulmonary pattern within the caudodorsal lung fields (Figure 1). Clinicopathologic abnormalities at the initial evaluation included mild hypokalemia (3.5 mmol/L; reference range, 3.7 to 5.8 mmol/L [reference range is different than that reported for dog 1 because of variation between equipment]), hyperglycemia (167 mg/dL; reference range, 60 to 110 mg/dL), and mild neutrophilia (13,760 cells/μL; reference range, 2,060 to 10,600 cells/μL). Results of serial analyses of venous blood gases were within reference limits. Treatments initiated on day 1 of hospitalization included ampicillin-sulbactam^h (23 mg/kg [10.45 mg/lb], IV, q 8 h), aminophylline (10 mg/kg, IM, q 8 h), and IV administration of isotonic crystalloid solution (100 mL/kg/d [45.5 mL/lb/d]). Administration of the antimicrobials was initiated as a prophylactic measure on the basis of a recommendation from the American Society for the Prevention of Cruelty to Animals' Poison Control Center.

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Lateral radiographic view of the thorax of a 10-month-old Chihuahua that was evaluated because of respiratory distress, vomiting, and anorexia. These clinical signs had developed approximately 18 hours after exposure to a waterproofing spray containing a highly flammable liquid hydrocarbon. A moderate interstitial pattern is evident in the caudodorsal lung fields (image obtained at the initial examination).

Citation: Journal of the American Veterinary Medical Association 231, 1; 10.2460/javma.231.1.74

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On the second day of hospitalization, SpO₂ (determined while the dog was breathing room air) was 88% but increased to 98% during administration of oxygen (FIO₂, 0.4). The respiratory rate during oxygen supplementation ranged from 30 to 68 breaths/min with moderate inspiratory effort evident at all rates. Although vomiting had ceased, the dog remained anorexic, and treatments (as previously described) were continued. On day 3, radiography revealed a more severe interstitial pattern in the caudodorsal lung fields. Despite provision of inhaled albuterol (90 μg, q 12 h) and nebulization with sterile water, the dog's respiratory status worsened; respiratory rate increased to 124 breaths/min and SpO₂ was 90% while the dog was receiving supplemental oxygen. Feedings administered via syringe into the oral cavity were started with amounts equivalent to 50% of the dog's resting energy requirements. Although SpO₂ improved on day 4 (96%; FIO₂, 0.3), the dog remained tachypneic throughout the period of hospitalization

Subsequent radiographic views obtained on days 5 and 8 revealed marked improvement, but incomplete resolution, of the interstitial lung pattern. Although gradual clinical improvement was evident, the dog was oxygen dependent until the final day of hospitalization (day 8), at which time SpO₂ was 97% while the dog was breathing room air. Dog 2 was discharged, and the owner was instructed to administer amoxicillin trihydrate-clavulanate potassiumⁱ (17 mg/kg [7.7 mg/lb], PO, q 12 h) for 10 days and aminophylline (10 mg/kg, PO, q 12 h) for 10 days; a further recommendation was to allow the dog to breathe humidified air twice daily. One year later, the dog was not receiving any medications and appeared physically normal according to the owner.