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PloS one2025; 20(5); e0325191; doi: 10.1371/journal.pone.0325191

Effect of orally administered cannabidiol oil on daily tonometric curve in healthy Italian Saddle horses.

Abstract: Phytocannabinoids have the potential to lower intraocular pressure in both normal and glaucomatous eyes and they have been tested in different animal species, but not in the horse. The present paper describes the tonometric curve of healthy adult Italian Saddle horses after oral administration of cannabidiol oil (CBD). Methods: CBD 20% was administered orally (oily solution) at the dose of 1 mg/kg to 8 adult horses and intraocular pressure (IOP) was evaluated by tonometric curve. Data were then compared to those of the same horses obtained the day before (blank) CBD administration. Results: 15 minutes after CBD administration, IOP (time zero 27.3 ± 2.1 mmHg right eye; 24.6 ± 2.3 mmHg left eye) started to decrease (19.5 ± 5.2 mmHg right eye; 20.8 ± 2.4 mmHg left eye) and 1 hour later CBD it reached the minimum level in all horses (11.4 ± 7.5 mmHg right eye; 9.5 ± 5.8 mmHg left eye), remaining statistically significantly lower than normal values for the entire observation period (8 hours; 12.0 ± 7.9 mmHg right eye; 11.9 ± 7.8 mmHg left eye). Conclusions: CBD 20% was effective to significantly reduce IOP in healthy adult Italian Saddle horses and may be an effective hypotensive agent to be implemented in case of primary or secondary glaucoma.
Copyright: © 2025 Bazzano et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
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Publication Date: 2025-05-28 PubMed ID: 40435047PubMed Central: PMC12118931DOI: 10.1371/journal.pone.0325191Google Scholar: Lookup
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Summary

This research summary has been generated with artificial intelligence and may contain errors and omissions. Refer to the original study to confirm details provided. Submit correction.

The study investigates the effect of cannabidiol oil (CBD) on eye pressure in horses, concluding that oral administration of the substance significantly decreased intraocular pressure for a period of eight hours. The findings imply potential benefits of CBD use in treating glaucoma in horses.

Research Purpose

  • The study was conducted to test the impact of orally-administered cannabidiol oil (CBD) on the eye pressure of horses, something that hadn’t been done before.
  • Through this research, the authors were seeking to gather data on the potential of phytocannabinoids to reduce intraocular pressure in horse. These have been shown to lower eye pressure in different animal species, could potentially be applicable to horses as well, potentially offering a treatment strategy for equine glaucoma.

Methodology

  • Eight adult Italian Saddle horses were planned for the study to test the effect of CBD on their intraocular pressure (IOP).
  • Each horse was administered a 20% solution of CBD orally at a dose of 1mg/kg body weight.
  • In order to measure the effect of the CBD, eye pressure data were compared between the day before the administration of the CBD and the day of the test. This was conducted through tonometric curve measurements, which shows pressure changes over a certain period.

Results

  • The IOP started to decrease 15 minutes after CBD administration, and within an hour it reached the minimum level in all horses.
  • There was a significant reduction in eye pressure—which was evident in both right and left eyes—maintained over an 8-hour observation period following CBD admission.

Conclusion

  • Overall, the study found that oral administration of a 20% CBD solution was effective in significantly reducing intraocular pressure in healthy Italian Saddle horses over an extended period.
  • The concluded efficacy of CBD in achieving this pressure reduction implies potential therapeutic benefits for primary or secondary glaucoma treatment in horses.

Cite This Article

APA
Bazzano M, Laus F, Cerquetella M, Spaterna A, Marchegiani A. (2025). Effect of orally administered cannabidiol oil on daily tonometric curve in healthy Italian Saddle horses. PLoS One, 20(5), e0325191. https://doi.org/10.1371/journal.pone.0325191

Publication

PloS one
ISSN: 1932-6203
NlmUniqueID: 101285081
Country: United States
Language: English
Volume: 20
Issue: 5
Pages: e0325191

Researcher Affiliations

Bazzano, Marilena
  • School of Biosciences and Veterinary Medicine, University of Camerino, Matelica, Italy.
Laus, Fulvio
  • School of Biosciences and Veterinary Medicine, University of Camerino, Matelica, Italy.
Cerquetella, Matteo
  • School of Biosciences and Veterinary Medicine, University of Camerino, Matelica, Italy.
Spaterna, Andrea
  • School of Biosciences and Veterinary Medicine, University of Camerino, Matelica, Italy.
Marchegiani, Andrea
  • School of Biosciences and Veterinary Medicine, University of Camerino, Matelica, Italy.

MeSH Terms

  • Animals
  • Horses
  • Cannabidiol / administration & dosage
  • Cannabidiol / pharmacology
  • Intraocular Pressure / drug effects
  • Administration, Oral
  • Tonometry, Ocular / veterinary
  • Male
  • Female
  • Italy

Conflict of Interest Statement

The authors have declared that no competing interests exist.

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