Evaluation of Scalibor® deltamethrin collar chronic exposure in dogs

Deltamethrin is a pesticide used worldwide with several applications in the control of nuisance arthropods in homes, agriculture, against ectoparasites in dogs and livestock. Recent studies indicate that deltamethrin can induce cardiotoxicity. Therefore, this study aimed to evaluate the toxicity of deltamethrin in dogs through exposure to commercial collars over 8 months. Twenty healthy dogs were selected, 9 males and 11 females, weighing between 10 and 15 kg and aged between 1 and 8 years, with no history of intentional exposure to pyrethroids. Clinical, cardiological, and laboratory evaluations were performed monthly. The results demonstrate that exposure to deltamethrin 4 % via the dermal route, through a commercial collar, was safe for 8 months, with preserved cardiac electrocontractile function, assessed by electrocardiogram and echocardiogram. In addition, tracking of plasma biochemical markers did not indicate signs of cardiac, renal, or hepatic injury. Although deltamethrin 4 % collars demonstrated an acceptable safety profile regarding cardiovascular and laboratory evaluations, the occurrence of dermatological reactions in 25 % of the animals, which is a significant proportion, highlights the need for careful monitoring of dermatological reactions. Future investigations with different concentrations and longer periods are recommended to achieve a more comprehensive understanding of the long-term effects of deltamethrin, improving its safe application in veterinary medicine and promoting animal and human health.