Benzalkonium chloride (BAC), a quaternary ammonium compound used as a cationic detergent, is commonly found in household cleaners and disinfectants as well as industrial cleaning agents. This retrospective study analyzed cases of cats that had been exposed to BAC and had their cases recorded in the Veterinary Poisons Information Service database in an effort to determine the onset, effects, and duration of clinical signs associated with BAC exposure.

Of the 245 cases of exposure for which follow-up information was available, 12 (4.9%) did not show clinical signs. The most common clinical signs (eg, hypersalivation, tongue and oral ulceration, hyperthermia, inappetence, lethargy, vomiting) were attributed to GI irritation. Some cats (22.1%) experienced respiratory signs (eg, respiratory distress, tachypnea, dyspnea, wheezing), and others (2.9%) had dermal irritation. The mean time for onset of clinical signs to appear was 6.4 hours, with a range of 5 minutes to 48 hours. Treatments were supportive in nature and included antibiotic therapy, fluids, analgesia, gastroprotectants, dermal decontamination, steroids, and atropine (for hypersalivation).

Three cats, all with respiratory signs, died following BAC exposure; it is unclear whether the respiratory distress was a clinically significant contributor. Most cats exposed to BAC developed clinical symptoms, with most achieving complete recovery following supportive care, although recovery was sometimes prolonged and damage significant.

Cats clearly demonstrate increased sensitivity to benzalkonium chloride, which is present in many everyday household products. The delay in onset of clinical signs can postpone intervention and treatment, potentially worsening tissue damage. If caught early, rinsing the oral cavity may help dilute the exposure and decrease the risk for worsening clinical effects. For clients calling with a potential benzalkonium chloride exposure, this highlights the importance of taking a complete toxicology history. Determining the type of exposure, active ingredients (and in what concentrations), and time since exposure can help to ensure immediate intervention, if warranted.—Sarah Gray, DVM, DACVECC