Domestic dog exposure to glyphosate in Australia

Abstract

Glyphosate is one of the most widely used herbicides globally, raising concerns about the risks associated with chronic exposure. While human biomonitoring studies have consistently detected glyphosate in urine worldwide, limited evidence suggests potentially higher exposure in companion animals. However, no data currently exist for Australian pets. This study aimed to quantify glyphosate and its primary metabolite, aminomethylphosphonic acid (AMPA), in Australian pet dog urine and estimate internal exposure levels. Urine samples from 71 dogs were analyzed using liquid chromatography–tandem mass spectrometry. Glyphosate and AMPA were detected above the limit of detection (0.2 µg/L and 0.5 µg/L) in 68% and 13% of the urine samples analyzed, respectively. Glyphosate was at a maximum concentration of 49 µg/L, approximately 40 times higher than the highest value reported in Australian human biomonitoring studies. Estimated daily intakes of glyphosate and total ∑glyphosate + AMPA reached 145 and 291 µg/kg body weight/day, respectively. Although no acceptable daily intake (ADI) has been established for dogs, these values represent roughly half of the Australian ADI for humans (300 µg/kg body wt/day). Questionnaire data did not reveal statistically significant exposure trends across the different dog demographics (age, gender, breed), dietary habits, living conditions, outdoor play or health conditions. This study provides the first evidence of glyphosate exposure in Australian dogs, suggesting potentially higher exposure compared to humans. These findings highlight the need for larger-scale investigations to identify exposure pathways and assess health risks for companion animals.