Albuterol Toxicosis in Dogs

Albuterol (ie, salbutamol) is a selective beta-2–adrenoreceptor agonist commonly used in human medicine as a bronchodilator and in the management of premature labor. Although albuterol has been used as a bronchodilator in dogs and cats, use in veterinary medicine is not common.¹ High doses of albuterol result in diminished beta-2 selectivity and activation of beta-1 adrenergic receptors, causing cardiovascular stimulation.² Systemic hypotension in response to albuterol-induced peripheral and coronary vasodilation can also contribute to increased heart rate.³ Hypokalemia may develop due to stimulation of sodium/potassium-ATPase via beta-2 adrenergic receptors.^4,5

Clinical signs of toxicosis are based on beta-agonist actions on adrenoreceptors in various organs. Most organs are affected, but the cardiovascular system, musculoskeletal system, and CNS are primarily affected. Clinical signs include tachycardia, tachypnea, lethargy, vomiting, muscle tremors, ataxia, agitation, and polydipsia. Most dogs develop clinical signs within several hours of exposure.  

This retrospective study evaluated onset and duration of common clinical signs, treatment, and outcome in 501 dogs with acute, accidental exposure to albuterol. Clinical signs developed in 471 dogs (94%) following albuterol exposure. Tachycardia was the most common clinical sign (404 dogs [80.6%]); median onset and duration were 2.5 and 13.3 hours, respectively. Tachypnea, dullness/lethargy, and vomiting were also common. Blood potassium concentration was measured in 142 dogs, and hypokalemia was reported in 106 dogs (median onset and duration were 2.4 and 13 hours, respectively). Beta-blockers, IV fluids, potassium supplementation, and sedation were the most common treatments. Survival rate among dogs with clinical signs was 99.6%.

Key pearls to put into practice:

Most dogs exposed to albuterol develop rapid-onset clinical signs but generally recover within 24 hours, and death is uncommon. Early assessment is recommended for all dogs with accidental exposure.

Beta-blockers are recommended in dogs with severe or prolonged tachycardia or with signs of reduced cardiac output/hypoperfusion (eg, pale mucous membranes, cold extremities, weak pulses, dull mentation) following albuterol exposure.

Serum potassium levels should be evaluated in all patients with clinical signs of toxicosis, and potassium supplementation should be considered in patients that are hypokalemic and have clinical signs (eg, muscle weakness, flaccid paralysis, hypoventilation) or ECG changes associated with hypokalemia (eg, prolonged QT interval, U waves, ST segment depression, increased P-wave amplitude and duration, bradycardia, AV block, cardiac arrest).