Insect repellents used on horses as reported by study respondents, and evidence for repellent efficacy in studies on humans

Ingredient/repellent typeTotal responses (% of participant responses*) (n=252)Evidence of repellency against mosquitoesEvidence of repellency against biting midges
N,N-Diethyl-meta-toluamide (DEET) (including Power Phaser)89 (35.3%)Yes28 35Yes36 37
Citronella48 (19.0%)Variable35No31
Power Phaser (DEET and IR3535)36 (14.3%)Yes35Yes37
NAF product (active ingredient not identified)25 (9.9%)
Home made25 (9.9%)
Citridiol (also known as oil of lemon eucalyptus, citriodora, PMD)24 (9.5%)Yes35 38Yes39
Neem oil19 (7.5%)Yes38Yes40
Avon skin so soft (citronellol)19 (7.5%)NoNo
Icaridin8 (3.2%)Yes†29 35Yes41
Tri-tec (cypermethrin and pyrethrins)‡3 (1.2%)
Coopers fly repellent (permethrin and citronellol)‡5 (2.0%)
Unintelligible25 (9.9%)
  • *Participants who did not respond to this question, or did not state that they used repellents were not included.

  • †Studies on both horses and humans.

  • ‡Usefulness of topical insecticides is unclear because of their inability to prevent blood-feeding, although treatment of infected horses may subsequently kill vectors that have blood-fed.42

  • PMD, p-Menthane-3,8-diol.