Study on species distribution and seasonal dynamics of equine tick infestation in Ardabil province, northwest of Iran.

Overview

• This study investigated the species diversity and seasonal patterns of hard tick infestations on horses and donkeys in Ardabil province, northwest Iran, throughout 2021.
• The research identified the main tick species infesting equids and analyzed the prevalence according to age groups and seasons.

Introduction and Background

• Ticks are ectoparasites that feed on the blood of animals and are notably problematic for equids (horses and donkeys).
• They cause economic losses in animal husbandry by impacting animal health and productivity.
• Understanding tick species distribution and infestation rates helps to design effective control measures.
• Ardabil province in northwest Iran has a notable population of equids important to local farming and transport.

Study Design and Methods

• Researchers selected 240 equids randomly: 187 horses and 53 donkeys from Ardabil province.
• Animals were examined during all four seasons to capture seasonal variation in tick infestation.
• Hard ticks (Ixodid ticks) were collected from the animals’ body surfaces and identified to species level.
• Tick infestation prevalence, number of ticks per animal (tick indices), and species composition were recorded.

Key Findings: Prevalence and Distribution

• Overall infestation:
  • 32.5% of horses were infested with ticks.
  • 4.58% of donkeys were infested.
  • A total of 412 hard ticks were collected from all examined animals.
  • The average number of ticks per infested animal (tick index) was 4.62 ticks.
• Age-related prevalence:
  • Equids aged 3 years or older had significantly higher tick infestation rates than younger ones.
• Seasonal dynamics:
  • Tick infestations occurred throughout the year, indicating a persistent risk of infestation.
  • The highest tick prevalence was recorded in spring, suggesting seasonal peaks in tick activity.

Species Diversity and Identification

• Ticks belonged to three genera:
  • Hyalomma spp.
  • Rhipicephalus spp.
  • Dermacentor spp.
• Four species were identified along with their relative abundances:
  • Hyalomma anatolicum: 73.05% (dominant species)
  • Hyalomma marginatum: 17.23%
  • Rhipicephalus bursa: 7.76%
  • Dermacentor marginatus: 1.94%

Implications and Recommendations

• High prevalence and multiple tick species indicate significant ectoparasite pressure on equids.
• Seasonal peaks, especially in spring, suggest timing considerations for tick control interventions.
• Older animals are more prone to infestations; targeted management or preventive measures may be needed for this group.
• The study underlines the need for further research to:
  • Understand the role of identified tick species as vectors of hemoparasites (blood parasites) in equids.
  • Develop appropriate control strategies to reduce economic losses and improve equid health in the region.