Bovine paramphistomes in Ireland

Area of Science:

• Veterinary Parasitology
• Ruminant Health
• Molecular Epidemiology

Background:

• Paramphistome infections, primarily caused by juvenile flukes, lead to significant morbidity in ruminants, historically concentrated in tropical/subtropical regions.
• Recent observations suggest an expanding geographical range and increased incidence of rumen fluke in Europe, prompting re-evaluation of its significance in temperate zones.
• The taxonomic identity of rumen flukes in the British Isles is under revision, necessitating updated assessments of their clinical and economic impact.

Purpose of the Study:

• To investigate recent changes in the incidence of rumen fluke infections in Ireland using historical diagnostic data.
• To identify the predominant paramphistome species in Ireland and assess its prevalence in cattle.
• To analyze the genetic diversity and population structure of Calicophoron daubneyi isolates in Ireland.

Main Methods:

• Retrospective analysis of diagnostic laboratory records for rumen fluke incidence in Ireland.
• Coprological monitoring for paramphistome eggs in three cattle herds over 2 to 14 months.
• Morphological and molecular typing (two loci) of adult rumen flukes collected post-slaughter.

Main Results:

• Calicophoron daubneyi was identified as the most common, if not sole, paramphistome species in Ireland.
• Cattle infections with rumen fluke have significantly increased in prevalence over the past five to six years.
• Genetic analysis revealed similar heterogeneity and predominant haplotypes across the island, comparable to Fasciola hepatica, with potential implications for drug resistance.

Conclusions:

• Calicophoron daubneyi is now highly prevalent in Irish cattle, indicating a significant increase in rumen fluke infections.
• The genetic characteristics of C. daubneyi in Ireland suggest potential for adaptation and resistance development.
• Rumen fluke should be considered a differential diagnosis for scour and ill-thrift in young calves, goats, and sheep due to its increasing prevalence.