To WormMail list.
Being the silly season, the conversation among the WormBoss Team has turned to things like worms of reindeer (and palindromes, typography (fonts) etc – all very important things).
In answer to a question about worms of reindeer, Maxine Lyndal-Murphy (a fabulous font of information) supplied us with a paper by J.T. Hrabok , A. Oksanen, M. Nieminen, A. Rydzik ,
A. Uggla , P.J. Waller. ( Hrabok et al, 2006. Reindeer as hosts for nematode parasites of sheep and cattle. Veterinary Parasitology 136 (2006) 297306)
The late Peter Waller of course was a well-known Australia parasitologist who worked for CSIRO.
Here are some excerpts:
"Limited information is available on the cross transmission potential of nematode parasites of reindeer to domestic ruminant species, or vice-versa.
Most work has focused on the protostrongylid nematodes (Elaphostrongylus spp.) responsible for cerebrospinal elaphostrongylosis in wild cervids, reindeer, sheep, goats, and cattle (for review see: Steen et al., 1998; Handeland and Sparboe, 1991;Handeland and Slettbakk, 1995).
Literature concerning gastro-intestinal nematodes has been limited to artificially infecting sheep and cattle with infective nematode larvae derived from reindeer (Borgsteede, 1982), and studies where viscera were examined from wild reindeer or caribou which had grazed on areas shared with sheep in northern Norway (Bye, 1987), and with sheep and goats in eastern Canada (Ball, 2000). There have been no studies, which examine the
infectivity potential of sheep and cattle nematode parasites in reindeer, in relation to their establishment in their definitive hosts. This study was designed to investigate these issues."
The reindeer husbandry range of Scandinavia overlaps with sheep, goat, and cattle pastures. The aim of this study was to determine whether reindeer are suitable hosts for ovine or bovine nematode parasites, and thus may spread these parasites into the reindeer husbandry regions.
To render worm-free, twelve 4-month-old male reindeer calves, six lambs, and six bovine calves were given ivermectin at 200 mg/kg body weight. Five weeks post-treatment, six reindeer calves were each artificially dosed with 10,000 third-stage larvae (L3) of gastrointestinal nematodes derived from sheep, and an additional six reindeer with L3 derived from cattle. Lambs and bovine calves received the same dose of ovine and bovine larvae as reindeer, from the same larval source, respectively. Faecal samples collected on five occasions after the larval dosing revealed that by the fourth week, all reindeer calves, lambs, and bovine calves were infected. Animals were slaughtered on days 40 (reindeer) or 47 (lambs and bovine calves) after the larval dosing.
Reindeer calves were most susceptible to L3 derived from sheep. The overall mean intensity of Haemonchus contortus, Trichostrongylus axei, and Teladorsagia circumcincta, did not differ between reindeer and sheep; however, early fourth-stage larvae of H. contortus were more abundant in reindeer ( p = 0.002). The establishment of bovine-derived Ostertagia ostertagi was similar in reindeer (62%) and bovine calves (57%), but larval inhibition was much higher in reindeer (91%, p < 0.001) than in cattle (31%).Very poor establishment of bovine derived Cooperia oncophora was recorded in reindeer calves (2%) compared with bovine
calves (59%). These results show that young reindeer are susceptible hosts to the important gastrointestinal parasites of sheep (T. circumcincta, H. contortus) and cattle (O. ostertagi), as well as being a suitable host for T. axei."
"This study demonstrated unequivocally that reindeer are highly suitable hosts for both bovine and ovine infective nematode larvae, particularly for the latter. There were no significant differences in the establishment of H. contortus, T. circumcincta, T. axei, and T. vitrinus between the natural definitive host (sheep) and reindeer. These species represent the economically most important nematode parasites of sheep and goats throughout the world."
"With regards to bovine nematodes…….. it appears that adult O. ostertagi in reindeer are not unduly affected by being in these hosts, as the mean lengths of male and female adult worms were marginally longer in reindeer than in their natural definitive host (cattle). In contrast, reindeer appeared to be unsuitable hosts for C. oncophora."
" Reindeer showed the presence of Capillaria sp. in faecal egg counts throughout this study. Little is known about this parasite in reindeer, but it is thought to reside distally in the small intestine (Skirnisson, personal communication). Its presence on all occasions, particularly after de-worming with ivermectin, yet prior to the L3 dosing, clearly indicates that this parasite is refractory to ivermectin. The occasional record of Nematodirus sp. eggs in reindeer faeces also indicates that these parasites survived ivermectin in low numbers. This species has been reported as being a dose-limiting parasite at the recommended dose of administration of ivermectin to reindeer (Oksanen, 1999). The small numbers of Trichuris sp. found in the caeca of reindeer may have been bovine and/or ovine derived as no examination of caeca of cattle or sheep was conducted in this study."
"More than 80% of reindeer herders in Finland de-worm the overwintering reindeer population with ivermectin, but their main goal is targeted at reducing the warble fly (Hypoderma tarandi) and throat bot fly (Cephenemyia trompe) infections (Oksanen, 1999). However, acquired ovine (or bovine) parasites would also have met a parasitological dead-end with such a control strategy."
|"Prevalence of gastrointestinal nematodes in winter slaughtered reindeer of northern Finland (2009)|
|Jackie T. Hrabok, Antti Oksanen, Mauri Nieminen, Peter J. Waller|
|The objective of this study was to determine the prevalence and intensity of gastrointestinal nematodes in winter-slaughtered reindeer during 2002-2004, from northern reindeer herding cooperatives in Finland.
Ostertagia gruehneri of the abomasum was prevalent with low levels of infections in 100% of calves, (n = 53; mean ≈ 1300 worms per animal) and in 98% of adults, (n = 41; mean ≈ 3900 worms per animal).
There was no difference in the number of O. gruehneri between male and female calves. The proportion of O. gruehneri inhibited larvae was significantly higher in calves (81%) than in adult reindeer (39%) (P = 0.005).
The intestinal nematodes, Nematodirus tarandi and Nematodirella longispiculata, were detected only in reindeer calves. The numbers of these worms did not differ between male and female calves, but there was a difference in abundance between sites. High prevalence and low intensity of gastrointestinal nematodes characterized the patterns of infection of the reindeer examined in this study. It is assumed that these infections are sub-clinical and would not contribute to productivity losses."
Something to ponder as you wash down your Christmas pudding.