Related Experiment Video
Updated: Dec 12, 2025
Development of an in vitro model system for studying the interaction of Equus caballus IgE with its high-affinity receptor FcεRI
Published on: November 1, 2014
Essential oil spray reduces clinical signs of insect bite hypersensitivity in horses
1School of Veterinary Science, The University of Queensland, Gatton, Queensland, Australia.
Objective:
To assess the efficacy of an herbal spray combining various essential oils, with a claim of mast cell stabilisation, antipruritic, anti-inflammatory, and insect repellent effects on the clinical presentation of insect bite hypersensitivity (IBH) in horses.
Design:
Double-blinded, placebo-controlled, randomised, cross-over clinical trial.
Methods:
Twenty adult horses with clinical IBH were treated with a daily application of herbal spray or placebo for 28 days in a randomised, cross-over fashion, separated by a>28-day washout period. Horses were examined and scored prior to and after the completion of each treatment. Histopathology was performed on four horses. Owners kept daily diaries of observations.
Results:
The herbal spray significantly reduced the severity of all assessed parameters (pruritus, excoriations, lichenification and alopecia; P < 0.05) compared with baseline values (pretreatment) and with placebo. Owners reported improvement of pruritus in 19/20 horses (95%) with complete resolution in 17 horses (85%) following treatment. Skin biopsies showed resolution of orthokeratosis in 4/4 horses, reduced thickness of the stratum spinosum in 2/4 horses and complete resolution of histopathological abnormalities in 1/4 horses after treatment, compared with either no change or deterioration of histopathologic lesions after placebo. No side effects were observed.
Conclusions:
The tested herbal spray may be an effective treatment for the management of equine IBH.
