Parascaris spp. eggs in horses of Italy: a large-scale epidemiological analysis of the egg excretion and conditioning factors.

This research investigates the prevalence and risk factors for the occurrence of the Parascaris spp., a parasitic infection in horses, particularly in Italy. The analysis involved 6896 horses, and the study suggests the need for improved treatment protocols, citing the role of young horses and outdoor-reared animals as strong risk indicators.

Background

• The study focuses on Equine ascariosis, a parasitic disease affecting horses worldwide, with young horses being particularly susceptible.
• While Italy has a high number of horses, large-scale epidemiological surveys on the prevalence of ascariosis are yet to be reported.
• The aim of the research was to outline, for the first time, the infestation of Parascaris spp. in a large population of Italian horses and identify risk factors associated with ascarid egg shedding.

Methods

• Individual rectal faecal samples collected during routine veterinary examinations were used to determine the prevalence of Parascaris spp.
• This prevalence was then analyzed against several factors, such as the horse’s age, sex, housing conditions, geographic origin, and the season when the samples were taken.

Results

• Findings revealed that 35.8% of the examined stables had at least one horse positive for Parascaris spp. eggs, with an overall prevalence rate of 6.3% among the tested population.
• There was a significant decrease of the ascariosis rates with the increasing age of horses, wherein, 80.0% of the Parascaris spp. eggs were found in 0.7% of the examined animals- the youngest ones.
• Prevalence rates varied significantly with different geographic areas of origin and were higher in horses raised outdoors compared to those reared indoors.
• However, data analysis based on sex and season did not reveal any prominent variations in the prevalence rates.

Significance & Recommendations

• The lower prevalence of ascariosis, as compared to other European countries, still signifies a major health challenge for horses reared in Italy, especially foals and yearlings.
• The age of the horses and the conditions they were reared in (outdoor/indoor) were identified as significant risk factors for Parascaris spp. egg shedding.
• Horses older than 6 years should not be overlooked as a potential source of infection for younger ones due to their high level of interaction.
• The study underscores the need for the development of improved treatment protocols, which could include regular faecal examination and follow-up evaluation of integrated action plans. This is crucial to preserve animal health and to mitigate anthelmintic resistance in the field.