Epidemiological study and risk factors of equine (Equus ferus caballus) gastrointestinal helminth infections in the north and northeast of Iran.

Overview

• This study investigated gastrointestinal (GI) helminth infections in horses from northern and northeastern Iran, identifying the prevalence, species involved, and risk factors associated with these infections.
• The research highlights the need for effective control measures, such as strategic deworming and grazing management, to reduce infection rates in these regions.

Background and Importance

• Gastrointestinal helminth infections in horses can cause significant health problems, impacting horse well-being and performance.
• Understanding epidemiology (distribution and determinants) of such infections is crucial to managing drug resistance and designing effective prevention strategies.
• Prior to this study, there was limited data on the prevalence and risk factors of equine GI helminths in northern and northeastern Iran.

Study Objectives

• To identify the prevalence and species of GI helminths infecting horses in north and northeast Iran.
• To analyze risk factors influencing infection rates, such as age, feeding type, and history of anthelminthic treatment.

Methodology

• Sample Collection: 340 fecal samples from horses located in northern (141 samples) and northeastern (199 samples) Iran.
• Diagnostic Techniques:
  • Coprological examination (microscopic fecal analysis) for presence of GI helminths.
  • Polymerase chain reaction (PCR) used for confirming specific egg presence.
  • Coproculture performed on positive samples to identify nematode larvae species.

Key Findings

• The overall prevalence of GI helminth infections in horses was 40.6%.
• Prevalence varied significantly by region:
  • North Iran: 55.3% (higher infection rate).
  • Northeast Iran: 30.2% (lower infection rate).
• Identified helminth species and their prevalence among the sampled horses included:
  • Strongylidae family: 27.9% (95/340 horses).
  • Parascaris sp.: 10% (34/340).
  • Anoplocephala sp.: 3.5% (12/340).
  • Oxyuris sp.: 1.2% (4/340).
  • Other minor species with lower frequencies.
  • Specific larval types in coprocultures: Strongylus spp. (67.4%), Triodontophorus spp. (29.5%), Cyathostominae (49.5%), and lesser prevalence species.
• Risk factor analysis revealed:
  • Feeding type significantly influenced prevalence: free-grazing horses had higher infection rates than stabled horses.
  • Age was not generally associated with infection rates, except Parascaris sp. infections were more frequent in younger horses.
  • Horses that received regular anthelminthic treatment had significantly lower infection rates when compared to untreated horses.

Implications and Recommendations

• The high prevalence of GI helminths in horses of northern and northeastern Iran suggests a substantial health burden.
• Strategic interventions are needed to control helminth infections, including:
  • Regular and targeted deworming programs utilizing broad-spectrum anthelminthics to reduce parasite load and prevent drug resistance.
  • Implementing rotational grazing to minimize pasture contamination and parasite transmission.
  • Monitoring infection status and treatment efficacy to optimize parasite management practices.