In vivo mosquito repellency effect of citronella (Cymbopogon nardus (L.) Rendle) essential oil bath bomb formulation in dogs

• DOI: 10.14202/vetworld.2024.1538-1544
• Publication Date: 2024-07-15T09:15:46Z
• Authors: Suwit Uopasai; Ketmanee Senaphan; Glenn Neville Bor...; Eakachai Thongkham; Jareerat Aiemsaard
• Keywords: 0301 basic medicine; culex quinquefasciatus; Mosquito Repellents; bath bomb formulation; In Vitro Evaluation; Geraniol; Veterinary medicine; vector control; Plant Science; SF1-1100; Essential oil; Agricultural and Biological Sciences; Food science; 03 medical and health sciences; Potential of Edible Insects as Food and Feed; SF600-1100; Biology; mosquito repellent; Life Sciences; cymbopogon nardus; Animal culture; Antimicrobial Properties of Essential Oils in Foods; Chemistry; Insect Science; Botanical Insecticides in Agriculture and Pest Management; Research Article; Food Science

Background and Aim: Mosquitoes carry numerous diseases of medical and veterinary significance. While citronella essential oil is safe as a mosquito repellent, extensive research does not document its ability to deter mosquitoes from animals. This study assessed the citronella essential oil bath bomb’s ability to repel Culex quinquefasciatus mosquitoes in dogs.

Materials and Methods: Citronella essential oil’s chemical composition was analyzed using gas chromatography-mass spectrometry (GC-MS). Through freeze-thaw testing, a bath bomb formulation containing 6% w/w citronella essential oil was assessed for its physical and chemical stability. Thirty-two healthy client-owned mixed-breed dogs were employed to test the mosquito-repellency effects of citronella essential oil (treatment group) and olive oil (control group) bath bomb formulations. Bath bombs were tested for irritation effects on animal skin for 15-day post-application.

Results: Thirty-six compounds were identified through GC-MS, with citronellal (23.38%), δ-cadinene (12.25%), and geraniol (9.09%) being the most prevalent constituents. The bath bomb maintained its original physical properties after undergoing six freeze-thawing cycles and retained over 90% of its citronella essential oil. About 100%, 69.28%, and 65.58% mosquito repellency were displayed by the citronella essential oil bath bomb at 3 h, 6 h, and 8 h, respectively. None of the test animals exhibited skin irritation during the study.

Conclusion: The citronella bath bomb effectively repelled C. quinquefasciatus in dogs without irritating their skin. The formulation’s physical and chemical stability is demonstrated by the results of freeze-thaw stability testing. Further studies should be conducted to evaluate the repelling activity against other mosquito species.

Keywords: bath bomb formulation, Culex quinquefasciatus, Cymbopogon nardus, mosquito repellent, vector control.