Publicação
First evaluation of the use of phoxim as a contribute to the control of Gasterophilus intestinalis burden in horses at pasture : a pilot study
| Resumo: | ABSTRACT - Gasterophilus intestinalis, also known as horse bot fly is a well-known parasite by horse owners. During spring and summer, the female insect lays up to 1000 eggs onto the coat of the horse, mainly in the frontlimbs. Phoxim is an organophosphate insecticide that acts by specifically inhibiting the enzyme acetylcholinesterase irreversibly. The objective of this study was to evaluate the feasibility and efficacy of utilising topical phoxim as a therapeutic strategy to reduce the egg load of G. intestinalis in horses under field conditions. This approach was designed to disrupt the parasite's life cycle before it is ingested and infects the horse. The reduction in the survival of G. intestinalis larvae in the treatment group and the impact of treatment on larval mortality over time were investigated. The study was carried out on fourteen purebred Lusitano horses, in Ribatejo, Portugal. Two groups of samples were formed with fourteen horses each. The samples were taken from the front limbs. The first group, the control group, included fourteen hair samples taken on the first day before the treatment was applied. The second group, being the treatment group, included the hair samples taken twenty-four hours after the application of phoxim, to the fourteen horses. All individual horses belonged both to the control and treatment group. The treatment solution was prepared by adding one millilitre of Byemite® (500 mg phoxim/mL) to one liter of water at forty degrees Celsius. The samples were observed under a stereo microscope, and the evolution of the eggs was analysed on days 1, 3, 7 and 10. The findings on the evolution of egg counts, live and dead larvae over time were consistent with the efficacy of phoxim treatment. It became evident that the number of eggs in the treatment group remained the same since the larvae had died, while the number of live larvae decreased, and the number of dead larvae increased over those days. This pilot study reveals some preliminary data that may contribute to the future inclusion of phoxim as an effective means of controlling G. intestinalis, particularly in Mediterranean climates. The observed alterations in eggs and larvae following treatment emphasize the necessity for further research, which could prove instrumental in preventing digestive issues concerning these parasites |
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| Autores principais: | Rodrigues, Teresa Pimentel Serrano |
| Assunto: | Gasterophilus intestinalis Phoxim Horse Lusitano Portugal Gasterophilus intestinalis Foxima Cavalo Lusitano Portugal |
| Ano: | 2024 |
| País: | Portugal |
| Tipo de documento: | dissertação de mestrado |
| Tipo de acesso: | acesso embargado |
| Instituição associada: | Universidade de Lisboa |
| Idioma: | inglês |
| Origem: | Repositório da Universidade de Lisboa |
| Resumo: | ABSTRACT - Gasterophilus intestinalis, also known as horse bot fly is a well-known parasite by horse owners. During spring and summer, the female insect lays up to 1000 eggs onto the coat of the horse, mainly in the frontlimbs. Phoxim is an organophosphate insecticide that acts by specifically inhibiting the enzyme acetylcholinesterase irreversibly. The objective of this study was to evaluate the feasibility and efficacy of utilising topical phoxim as a therapeutic strategy to reduce the egg load of G. intestinalis in horses under field conditions. This approach was designed to disrupt the parasite's life cycle before it is ingested and infects the horse. The reduction in the survival of G. intestinalis larvae in the treatment group and the impact of treatment on larval mortality over time were investigated. The study was carried out on fourteen purebred Lusitano horses, in Ribatejo, Portugal. Two groups of samples were formed with fourteen horses each. The samples were taken from the front limbs. The first group, the control group, included fourteen hair samples taken on the first day before the treatment was applied. The second group, being the treatment group, included the hair samples taken twenty-four hours after the application of phoxim, to the fourteen horses. All individual horses belonged both to the control and treatment group. The treatment solution was prepared by adding one millilitre of Byemite® (500 mg phoxim/mL) to one liter of water at forty degrees Celsius. The samples were observed under a stereo microscope, and the evolution of the eggs was analysed on days 1, 3, 7 and 10. The findings on the evolution of egg counts, live and dead larvae over time were consistent with the efficacy of phoxim treatment. It became evident that the number of eggs in the treatment group remained the same since the larvae had died, while the number of live larvae decreased, and the number of dead larvae increased over those days. This pilot study reveals some preliminary data that may contribute to the future inclusion of phoxim as an effective means of controlling G. intestinalis, particularly in Mediterranean climates. The observed alterations in eggs and larvae following treatment emphasize the necessity for further research, which could prove instrumental in preventing digestive issues concerning these parasites |
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