Occurrence of Thelazia lacrymalis (Nematoda, Spirurida, Thelaziidae) in native horses in Italy.

This research involved a study on the prevalence of the Thelazia Lacrymalis parasite in native Italian horses. The study found that approximately 14.7% of the horses surveyed were infected by the parasite, which was most commonly found in horses aged 3-4 years.

Research Purpose and Methodology

• The research aimed at studying the occurrence of the Thelazia Lacrymalis parasite in horses from the province of Bari, in the Apulia region of Italy.
• During the study, both eyes of 409 native Italian horses aged between ten months and four years were examined. The research spanned from June 20, 1995, to April 3, 1996.
• The study involved slaughtered horses, a practical choice, as it allowed for a comprehensive and invasive examination which would not be possible or ethically appropriate with living specimens.

Findings

• Out of the 409 horses examined, 60 of them (approx 14.7%) were parasitized by Thelazia Lacrymalis.
• In total, 361 parasite specimens were found – comprising 220 females, 99 males, and 42 larvae. They were most commonly found inside conjunctiva, behind the nictitancte, in the excretory ducts of the Harderian gland, and the lacrimal glands ducts.
• The mean count burden per horse ranged from 1 to 20, with an average between 6.0 and 5.1.
• The research found that Thelazia specimens were significantly more frequent in horses aged 3-4 years.
• All infected animals showed symptoms of follicular conjunctivitis – inflammation of the conjunctiva, the clear tissue that lines the inside of the eyelid and the white portion of the eyeball. This suggests that Thelazia plays a role in this inflammation.

Significance of the Research

• This study is the first of its kind to report T. Lacrymalis horse infection in Italy so it represents a fundamental step forward in identifying and understanding the spread of this parasite in the Italian equine population.
• By understanding the prevalent age group and the symptoms of the infection, the research provides valuable information for equine healthcare providers and could lead to improved strategies for prevention and treatment of infections caused by T. Lacrymalis.