Elaphostrongylus rangiferi

Handeland, Kjell, Tunheim, Ketil, Madslien, Knut, Vikøren, Turid, Viljugrein, Hildegunn, Mossing, Anders, Børve, Ivar, Strand, Olav & Hamnes, Inger Sofie, 2021, High winter loads of Oestrid larvae and Elaphostrongylus rangiferi are associated with emaciation in wild reindeer calves, International Journal for Parasitology: Parasites and Wildlife 15, pp. 214-224 : 219-221

3.2.2. Elaphostrongylus rangiferi

As expected, none of the calves shot in the autumns of 2014 and 2015 excreted Elaphostrongylus L 1 in faeces (calves normally do not develop patent infection until after the hunting season). The prevalence, intensity, and abundance of Elaphostrongylus larval faecal excretion in the calves killed in spring are shown in Table 3. The prevalence and abundance of infection were significantly higher (p = 0.003; p <0.001) in the spring of 2015, compared to the spring of 2016. Histological examination of lung tissues from calves excreting E. rangiferi L 1 larvae in faeces, revealed disseminated microgranulomas containing Elaphostrongylus eggs and hatching L 1 larvae. Half of the calves displayed light-, and the remainder moderate to heavy- presences of microgranulomas. A massive and confluent presence of microgranulomas with extensive destruction of respiratory tissues was observed in the lungs of the most severely infected calf ( Fig. 7 ).

No adult Elaphostrongylus nematodes were detected in the CNS of any of the calves examined in spring, whereas 1–22 nematodes were successfully identified in the skeletal muscles ( Fig. 8 ) of five of the calves

b One calf was of unknown sex.

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excreting L 1 larvae in faeces (detection of this hair-thin organism is challenging in skeletal muscle tissues). The calf with the highest number of recovered nematodes also excreted the most L 1 larvae in faeces (LPG: 1632). Isolated nematodes were identified morphologically to the genus Elaphostrongylus (Cameron, 1931) . Although not speciated, we conclude, based on the host species and fecal excretion of typical L 1 larvae, that

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b A measure of the mean level of infection in all hosts, including non-infected individuals.

these nematodes were indeed E. rangiferi .

Figures

Fig. 7. Verminous pneumonia in a calf killed on Hardangervidda in spring 2015. Numerous confluent granulomas containing Elaphostrongylus rangiferi eggs and hatched first stage larvae. Haematoxylin and eosin stain. Bar, 100 μm.

Fig. 8. Group of adult hair-thin, about 3–5 cm long Elahostrongylus rangiferi nematodes in the muscle fascia of a calf killed on Hardangervidda in spring 2015.