The prevalence and epidemiology of Anoplocephala perfoliata infection in Norway.

This research investigates the presence of a cestode parasite Anoplocephala perfoliata in horses in two regions of Norway, noting the prevalence and factors influencing infestation. The study also evaluates the effectiveness of faecal examinations in diagnosing the infection.

Study and Methodology

• The study evaluated 201 horses from two different regions in Norway, Ostlandet and Trøndelag, for infection of Anoplocephala perfoliata, a type of cestode parasite, commonly known as a tapeworm.
• The research focused on examining the caecum and adjacent lengths of the ileum and large colon in these horses.
• Data were gathered on various factors such as horse age, sex, breed, type of pasture, and their anthelmintic, or anti-parasitic, treatment after the grazing season.

Findings

• Around 20% of the total horses were found infected with the parasite, with regional variations of 27% in Ostlandet and 7% in Trøndelag.
• The average number of cestodes in infected horses varied in the two regions, with 18 in Ostlandet and 6 in Trøndelag.
• There was no substantial evidence to link A. perfoliata infestation with age, breed, or sex of the horses.
• The study found a high odds ratio (8.8) for horses grazing on permanent pastures that had a history of being used by horses for at least the last five consecutive years. This suggests a higher likelihood of A. perfoliata infestation in such pastures.
• The research observed a significantly greater infestation occurrence in Ostlandet, demonstrated by an odds ratio of 3.1.

Comparisons and Diagnostics

• The study discussed the relatively low prevalence of A. perfoliata infestation in Norwegian horses compared to other countries, suggesting regional differences.
• Gross pathological examination of the infected horses found all of them with consistent lesions, such as thickening of the mucosal layer, hyperemia, or increased blood flow, and erosions. These contrasts with only 5% such observations in non-infected horses.
• Only 3 out of 26 fecal samples from infected horses revealed the presence of cestode eggs. This finding led to the conclusion that a fecal examination may not be a reliable diagnostic method for A. perfoliata infestation.