Assessing the Resilience Factor: A Preliminary Investigation into a Multifaceted Approach to Individual Parasite Control in Thoroughbred Foals

Eduarda  Proença; Irineu R.  Neto; Alan J.  Ferreira; Ursula Y.  Yoshitani; Marcelo B.  Molento

doi:10.64292/ijes.205

Authors

Eduarda Proença Laboratory of Veterinary Clinical Parasitology, Federal University of Paraná, Paraná, 80.035-050, Brazil https://orcid.org/0009-0002-9484-1734
Irineu R. Neto Laboratory of Veterinary Clinical Parasitology, Federal University of Paraná, Paraná, 80.035-050, Brazil https://orcid.org/0000-0001-8727-9566
Alan J. Ferreira Haras Rio Iguassu, Avenida Victor Ferreira do Amaral, Paraná, 82.800-000, Brazil https://orcid.org/0009-0003-1321-9431
Ursula Y. Yoshitani Laboratory of Veterinary Clinical Parasitology, Federal University of Paraná, Paraná, 80.035-050, Brazil https://orcid.org/0000-0001-8941-6050
Marcelo B. Molento Laboratory of Veterinary Clinical Parasitology, Federal University of Paraná, Paraná, 80.035-050, Brazil https://orcid.org/0000-0003-0572-5628

DOI:

https://doi.org/10.64292/ijes.205

Keywords:

Strongyle, body growth, yearlings, gastrointestinal infection, personality

Abstract

Standard equine management practices contribute to the high prevalence of strongyles and to the need for deworming. Horse performance can be evaluated by following early body development. This study aimed to determine the behavior and body growth associated with strongyle fecal egg count (FEC) in 25 Thoroughbred foals aged from birth to 10 months in southern Brazil. Body weight, withers height, and FEC were determined monthly, and foals' behavior/personality was recorded twice daily by resident veterinarians following standard welfare protocols. A generalized linear mixed model was used to analyze body growth and FEC variance. There was a high correlation between weight gain before six months of age and between height and age. Although males exhibited greater variability in weight and height, no statistically significant differences were observed between sexes (P > 0.05). There was no significant association between strongyle FEC and body weight or height in any animals. Descriptive behavioral analysis revealed that only four animals were treated based on behavior/personality alterations and clinical signs (i.e., abdominal discomfort). The data showed a null-to-weak correlation between FEC and the animals' age (R² = −0.025 for females and R² = 0.168 for males). Moreover, foals had a low (0.206) FEC repeatability coefficient for sex and age, while individual overdispersion indicated a high (3.919) value. This information is crucial when designing health protocols for horses, as the expected rise in FEC after treatment may indicate a new infection that accompanies a suppressive drug strategy. These preliminary data showed that foals experienced steady body growth, independent of FEC, allowing selective treatment to be guided by a combination of periodic clinical and analytical parasitological examinations. Furthermore, this study highlights the intrinsic influence of constant veterinary care and the protection of horse health as a strong component of farm resilience.

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