Prevalence and risk factors of gastrointestinal nematode infestation of horses, donkeys and mules in tropical, dry and temperate regions in Mexico.

The research paper investigates the prevalence of gastrointestinal worms in horses, donkeys, and mules across different climate regions in Mexico and identifies potential risk factors linked with these infestations, with a focus on age, sex, and climate factors.

Overview of the Research

• The study aims to understand the extent of the problem of gastrointestinal nematodes (GIN), a type of worm that can affect the digestive system of horses, donkeys, and mules. The researchers wished to identify the potential risk factors that contributed to GIN infestations across different climate regions in Mexico. Understanding this could aid in developing preventative and treatment methods for GIN infestations.
• The research was conducted through a questionnaire that was filled out by 560 farm owners or managers between May 2017 and April 2018. This provided data from many different farms and covered a broad range of climatic conditions, with the farms categorized into tropical, dry, and temperate climatic regions according to the Köppen climate classification system.

Findings of the Study

• The overall prevalence of GIN infestation was found to be 77.9%, suggesting that GIN is a common issue in horses, donkeys, and mules across the sampled areas. Mules were found to have the highest rate of infestation at 87.5%.
• When divided according to climatic regions, it was found that the highest prevalence of GIN was in temperate climates, at 79.9%. However, the number of strongylid eggs per gram of feces, a measure of severity of infestation, was highest in dry climates.
• The identified nematodes included the strongyle type most commonly, as well as Parascaris equorum, Strongyloides, and Oxyuris equi. The differences in prevalence of these different nematodes also provide valuable insight for future prevention and treatment strategies.

Risk Factors

• The study found that age and sex were significant risk factors for higher intensity GIN infestations, especially in terms of strongyle egg shedding. Geldings (castrated male horses) and older equines (≤16 years old and 6-10-year-old) had higher odds ratios, indicating a larger risk of high intensity infestations compared to mares and young equines (≤5 years old).