Seasonality, control, and risk factors for Gasterophilus intestinalis egg intensity in horses from Romania under field conditions.
Abstract: This study aimed to assess the efficacy of pyrethroid-based insecticides against Gasterophilus spp. egg-laying activity and to establish the seasonality patterns in the specific climatic area of Transylvania, Romania. To fulfil the aims of the study, a total of 40 horses were treated every 4 weeks and inspected every 2 weeks between 11 May and 6 November (Pilo et al. Parasitol Res 114:1693-1702, 2024). Through this period, eggs were found between 24 June and 2 November. The eggs were found on 34 out of 40 horses (prevalence = 85%, CI 95% = 73.43-96.56%). Overall, a total of 50,029 Gasterophilus spp. eggs were counted during this study, and all were morphologically identified as G. intestinalis. Statistical analysis revealed no significant difference in prevalence and intensity between treated and control horses (p > 0.05). The number of laid eggs varied significantly across body regions (p < 0.05). The risk factors associated with increased egg-laying activity were significantly (p 0.05). The applied statistical tests were as follows: the non-parametric Mann-Whitney U test, the Friedman test, Wilcoxon test corrected by the Bonferroni method, the Kruskal-Wallis test, and the Bonferroni correction for multiple comparisons. These results highlight gasterophilosis as an important parasite in horses. In conclusion, we recommend that, in order maintain a low prevalence of Gasterophilus spp., treatment should include the use of larvicidal drugs and the mechanical removal of the eggs.
© 2025. The Author(s).
Publication Date: 2025-08-06 PubMed ID: 40767875PubMed Central: PMC12328499DOI: 10.1007/s00436-025-08540-xGoogle Scholar: Lookup
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Summary
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The paper discusses a study undertaken to understand the efficacy of pyrethroid-based insecticides on egg-laying activity of Gasterophilus spp., a parasite in horses. The research also aimed at identifying the pattern of this activity in the specific climate of Transylvania, Romania, and the influencing risk factors. The study found no significant difference in the prevalence and intensity of the parasite’s eggs between treated and control horses. However, certain factors were identified as significantly associated with increased egg-laying activity of the parasite.
Study Setup and Procedure
- The study was carried out over six months (from May to November) using 40 randomly selected horses.
- All the horses were observed every two weeks, and treated every four weeks with pyrethroid-based insecticides.
- Throughout the study period, the Gasterophilus spp. eggs were collected, counted and identified. A total of 50,029 eggs were counted, all of which were identified as G. intestinalis.
Results and Analysis
- A statistical analysis was conducted to compare the prevalence and intensity of eggs between horses that were treated with pyrethroid-based insecticides and those that were not (control). The results showed no significant difference between the two groups.
- The study also found that the number of eggs laid varied significantly across different body regions of the horses.
- Various factors influencing the egg-laying activity of the parasite were identified, including the color of the horse’s coat, outside husbandry regime, and the month of exposure. Horses with dark color coats, those living outside, and horses exposed in certain months had a significantly higher risk of egg-laying activity.
- Contrarily, other factors such as the gender and age of the horses were not found to significantly influence the prevalence of eggs.
Conclusion and Recommendations
- The study concluded that Gasterophilus spp. is a significant parasite in horses, and a considered regimen comprising of larvicidal drugs and manual removal of eggs is recommended for control.
- The authors also recommend further research in other climatic areas and with larger sample size for more comprehensive understanding of the parasite’s behavior and treatment efficacy.
Cite This Article
APA
Rabei ȘO, Pivariu D, Cocian AI, Vaccaro D, Costache-Bobescu P, Mihalca AD.
(2025).
Seasonality, control, and risk factors for Gasterophilus intestinalis egg intensity in horses from Romania under field conditions.
Parasitol Res, 124(8), 87.
https://doi.org/10.1007/s00436-025-08540-x Publication
Researcher Affiliations
- Department of Parasitology and Parasitic Diseases, Faculty of Veterinary Medicine, University of Agricultural Sciences and Veterinary Medicine of Cluj-Napoca, 400372, Cluj-Napoca, Romania. stefan-ovidiu.rabei@usamvcluj.ro.
- Department of Toxicology, Faculty of Veterinary Medicine, University of Agricultural Sciences and Veterinary Medicine of Cluj-Napoca, 400372, Cluj-Napoca, Romania.
- Department of Parasitology and Parasitic Diseases, Faculty of Veterinary Medicine, University of Agricultural Sciences and Veterinary Medicine of Cluj-Napoca, 400372, Cluj-Napoca, Romania.
- Department of Parasitology and Parasitic Diseases, Faculty of Veterinary Medicine, University of Agricultural Sciences and Veterinary Medicine of Cluj-Napoca, 400372, Cluj-Napoca, Romania.
- Ceva Sante Animale Romania, Strada Chindiei Nr. 5, Sector 4, 040185, Bucharest, Romania.
- Department of Parasitology and Parasitic Diseases, Faculty of Veterinary Medicine, University of Agricultural Sciences and Veterinary Medicine of Cluj-Napoca, 400372, Cluj-Napoca, Romania. amihalca@usamvcluj.ro.
- Parasitology Consultancy Group, 407056, Corușu, Romania. amihalca@usamvcluj.ro.
MeSH Terms
- Animals
- Horses / parasitology
- Romania / epidemiology
- Seasons
- Risk Factors
- Horse Diseases / parasitology
- Horse Diseases / epidemiology
- Horse Diseases / prevention & control
- Female
- Prevalence
- Male
- Parasite Egg Count / veterinary
- Insecticides / pharmacology
- Pyrethrins / pharmacology
Conflict of Interest Statement
Declarations. Ethics approval: All horse owners allowed the enrollment of their animals in this study by signing an agreement for participation. Consent of publication: Not applicable. Competing interests: The authors declare no competing interests.
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