# Spiculopteragia boehmi is the dominant abomasal nematode species in reindeer (Nordland County, Norway) sharing pasture with wild and domesticated ruminants

## TL;DR

This study found that Spiculopteragia boehmi is the main abomasal nematode in reindeer in Norway, with potential zoonotic risks from Giardia.

## Contribution

The study identifies Spiculopteragia boehmi as the dominant abomasal nematode in reindeer in a specific Norwegian region.

## Key findings

- Spiculopteragia boehmi was the most prevalent abomasal nematode in the studied reindeer.
- Giardia duodenalis Assemblage B, a zoonotic parasite, was detected for the first time in semi-domesticated reindeer.
- Faecal egg counts did not correlate with abomasal nematode counts, highlighting seasonal sampling importance.

## Abstract

Gastrointestinal parasites, especially those in the abomasum, are considered important production-limiting parasites of ruminants. Reindeer harbour many species of gastrointestinal parasites, and Ostertagia gruehneri, considered their dominant abomasal parasite, has been relatively extensively studied. This study aimed to assess the prevalence, species composition, and burdens of gastrointestinal parasites in a relatively southern flock of semi-domesticated reindeer in Duokta, Norway. In Duokta, a lower number of reindeer than domestic sheep share pastures, alongside an increasing moose population and a relatively new roe deer population. In the present study, visceral and faecal samples were collected during the winter slaughter of 47 semi-domesticated reindeer in 2020 in a local slaughterhouse in Duokta. The samples were analysed qualitatively and quantitatively.

From the 47 animals, 16 visceral and 42 faecal samples were collected. Subsamples of the abomasum were checked for numbers and species of nematodes. A McMaster method, Baermann technique, and a direct immunofluorescent antibody test was used to analyse the faecal samples. Four nematode species were detected from the abomasum samples (Spiculopteragia boehmi, Ostertagia gruehneri, Teladorsagia circumcincta and Mazamastrongylus dagestanica). All of the animals had low numbers of eggs, oocysts or cysts of at least one parasite species in their faeces, whereas higher numbers of larvae were found. Molecular analysis revealed Giardia duodenalis Assemblage A and B. Both have zoonotic potential and the latter is not previously reported from semi-domesticated reindeer.

The abomasal nematode fauna was dominated by Spiculopteragia boehmi, a species of uncertain significance, though no apparent impact on the slaughter weights was observed. The faecal egg counts was not correlated with the abomasal nematode counts, underscoring the importance of considering season of sampling. The brainworm Elaphostrongylus rangiferi was found at a high, but not exceptional, prevalence in reindeer older than 1.5 years, consistent with previous studies from Norway. Zoonotic Giardia assemblages may indicate potential for anthropozoonotic transmission.

The online version contains supplementary material available at 10.1186/s13028-026-00853-w.