Life history matters: Differential effects of abomasal parasites on caribou fitness.

Parasites can impact wildlife populations through their effects on host fitness and survival. The life history strategies of a parasite species can dictate the mechanisms and timing through which it influences the host. However, unravelling this species-specific effect is difficult as parasites generally occur as part of a broader community of co-infecting parasites. Here, we use a unique study system to explore how life histories of different abomasal nematode species may influence host fitness. We examined abomasal nematodes in two adjacent, but isolated, West Greenland caribou (Rangifer tarandus groenlandicus) populations. One herd of caribou were naturally infected with Ostertagia gruehneri, a common and dominant summer nematode of Rangifer sspp., and the other with Marshallagia marshalli (abundant; winter) and Teladorsagia boreoarcticus (less abundant; summer), allowing us to determine if these nematode species have differing effects on host fitness. Using a Partial Least Squares Path Modelling approach, we found that in the caribou infected with O. gruehneri, higher infection intensity was associated with lower body condition, and that animals with lower body condition were less likely to be pregnant. In caribou infected with M. marshalli and T. boreoarcticus, we found that only M. marshalli infection intensity was negatively related to body condition and pregnancy, but that caribou with a calf at heel were more likely to have higher infection intensities of both nematode species. The differing effects of abomasal nematode species on caribou health outcomes in these herds may be due to parasite species-specific seasonal patterns which influence both transmission dynamics and when the parasites have the greatest impact on host condition. These results highlight the importance of considering parasite life history when testing associations between parasitic infection and host fitness.

Pharmacokinetics of a long-acting subcutaneous eprinomectin injection in semi-domesticated reindeer (Rangifer tarandus tarandus) - A pilot study.

Reindeer (Rangifer tarandus tarandus) are exposed to the pathogenic parasitic nematode Elaphostrongylus rangiferi during grazing. The severity of disease is dose-dependent. Prophylactic anthelmintic treatment is needed to improve animal health and reindeer herding sustainability. Herds are traditionally only gathered once during the summer, requiring a drug with a persistent effect. In this study we investigated the suitability of long-acting eprinomectin, given as a single subcutaneous injection at 1 mg/kg bodyweight in adult reindeer and calves. Plasma and faeces concentrations were determined using ultra-high performance liquid chromatography high resolution mass spectrometry (UHPLC-HRMS). Plasma concentrations remained above the presumed effect level of 2 ng/mL for 80 days, demonstrating the drug's potential. Pharmacokinetic parameters were compared to other species using allometric scaling. Calves and adults had slightly different profiles. No viable faecal nematode eggs were detected during treatment. Eprinomectin was measurable in the reindeer faeces up to 100 days, which is of environmental concern.

First report of Orthostrongylus sp. (Nematoda: Protostrongylidae) in wild reindeer (Rangifer tarandus) from the Taimyr, Russia: Nearctic parasites in a Palearctic host.

First stage larvae of an unknown lungworm (Protostrongylidae) were isolated in the feces of a wild reindeer (Rangifer tarandus) from Taimyr, Russia. Larvae were 365-366 µm long and had a tail spike lacking a dorsal spine. DNA analyses using BLAST showed that nuclear sequences obtained (LSU rDNA, 825 bp and ITS2 rDNA, 395 bp) were highly similar (99.50% and 98.88% identity, respectively) to an isolate of Orthostrongylus macrotis (GenBank: EU595592.1) from North America. It cannot be confirmed whether these larvae represent an uncharacterized species of Orthostrongylus or can be referred to O. macrotis, a species that has historically only been reported from the Nearctic. This is the first report of lungworms attributable to Protostrongylinae in R. tarandus across its vast geographic in the Holarctic.

Contributions of CO2-Baited Malaise-Type Traps to the Knowledge of Hematophagous and Oestrid Flies (Diptera: Oestridae) Parasitizing Cervid Hosts.

This review describes an innovative and efficient modification of a type of Malaise trap meme overlooked in a recent review of such insect traps. It further identifies the large variety of dipteran parasites of vertebrates caught in the traps when CO2 was added as an attractant that otherwise rarely were caught in unbaited traps. Baited trap catches of parasitic flies mimicked those caught attacking cervid hosts. This review particularly focuses on comprehensive studies of: 1) several hematophagous species of largely unknown snipe flies (Diptera: Rhagionidae: Symphoromyia [Artiodactyla: Cervidae]) found host specific for Columbian black-tailed deer (Odocoileus hemionus columbianus Richardson), and 2) the biology of oestrid fly (Diptera: Oestridae) parasites of black-tailed deer and caribou/reindeer [Rangifer tarandus (L.) (Artiodactyla: Cervidae)], after it was discovered that the non-hematophagous females are guided to their vertebrate hosts by tracking a source of CO2, as done by many hematophagous flies.

A historical review of Babesia spp. associated with deer in Europe: Babesia divergens/Babesia divergens-like, Babesia capreoli, Babesia venatorum, Babesia cf. odocoilei.

This review is intended to provide an overview of the occurrence and diversity of Babesia spp. in European deer. Babesiosis is an emerging vector-borne disease with negative implications on animal and public health. Cervidae are important hosts for Ixodidae ticks, playing a critical role in the epidemiology of the parasite. Deer are susceptible to different Babesia spp., some of them with zoonotic potential. The infection is usually asymptomatic with high prevalence rates, although some fatal cases due to B. capreoli and B. venatorum have been reported. In Europe, 3 main Babesia spp. have been described in deer: Babesia divergens/B. divergens-like, B. capreoli and B. venatorum. Additionally, close relatives of B. odocoilei, the Babesia species of the American white-tailed deer (Odocoileus virginianus), have been isolated in several European countries. The occurrence of B. divergens/B. divergens-like generated concerns about the role of cervidae in the life cycle of the parasite, and the potential threat for public health. Few human cases have been attributed to B. venatorum so far, including hunters. Although this species is strictly related to the presence of roe deer (Capreolus capreolus), it has been occasionally reported in moose (Alces alces) and captive reindeer (Rangifer tarandus). Over recent years, vector-borne diseases received increased attention from International Organizations. However, technical difficulties persist, affecting surveillance efficiency. Given the veterinary and zoonotic importance of babesiosis, the author advocates the need for an effective monitoring at wildlife-domestic animals-humans interface and the implementation of management plans to reduce the risk of Babesia spp. infection for both humans and domestic animals.

Range expansion of muskox lungworms track rapid arctic warming: implications for geographic colonization under climate forcing.

Rapid climate warming in the Arctic results in multifaceted disruption of biodiversity, faunal structure, and ecosystem health. Hypotheses have linked range expansion and emergence of parasites and diseases to accelerating warming globally but empirical studies demonstrating causality are rare. Using historical data and recent surveys as baselines, we explored climatological drivers for Arctic warming as determinants of range expansion for two temperature-dependent lungworms, Umingmakstrongylus pallikuukensis and Varestrongylus eleguneniensis, of muskoxen (Ovibos moschatus) and caribou (Rangifer tarandus), in the Canadian Arctic Archipelago from 1980 through 2017. Our field data shows a substantial northward shift of the northern edge of the range for both parasites and increased abundance across the expanded ranges during the last decade. Mechanistic models parameterized with parasites' thermal requirements demonstrated that geographical colonization tracked spatial expansion of permissive environments, with a temporal lag. Subtle differences in life histories, thermal requirements of closely related parasites, climate oscillations and shifting thermal balances across environments influence faunal assembly and biodiversity. Our findings support that persistence of host-parasite assemblages reflects capacities of parasites to utilize host and environmental resources in an ecological arena of fluctuating opportunity (alternating trends in exploration and exploitation) driving shifting boundaries for distribution across spatial and temporal scales.

Range expansion and reproduction of the ectoparasitic deer ked (Lipoptena cervi) in its novel host, the Arctic reindeer (Rangifer tarandus tarandus), in Finland.

The deer ked (Lipoptena cervi) is a harmful ectoparasite that emerged in the reindeer herding area of Finland in 2006. To understand the current range and the intensity of infestations on its novel reindeer host, we studied deer ked pupae collected from reindeer and moose bedding sites and conducted a questionnaire survey among the managers of 18 reindeer herding cooperatives in the southern part of the reindeer herding area. Our study confirmed that the deer ked can survive and successfully reproduce on reindeer through winter and that flying deer keds had been observed in reindeer wintering areas during several autumns in twelve cooperatives. The pupae originating from reindeer were smaller and showed lower hatching rates than the pupae from moose. The present results indicate that the range of the deer ked infestations on reindeer in Finland expanded during the recent 5 years, now reaching 14 cooperatives and bordering an area south of approximately 66° N 25° E in the west and 65° N 29° E east.

Behavioral, Physiological, Demographic and Ecological Impacts of Hematophagous and Endoparasitic Insects on an Arctic Ungulate.

Animals that deliver a toxic secretion through a wound or to the body surface without a wound are considered venomous and toxungenous, respectively. Hematophagous insects, such as mosquitoes (Aedes spp.), meet the criteria for venomous, and some endoparasitic insects, such as warble flies (Hypoderma tarandi), satisfy the definition for toxungenous. The impacts of these insects on their hosts are wide ranging. In the Arctic, their primary host is the most abundant ungulate, the caribou (Rangifer tarandus). The most conspicuous impacts of these insects on caribou are behavioral. Caribou increase their movements during peak insect harassment, evading and running away from these parasites. These behavioral responses scale up to physiological effects as caribou move to less productive habitats to reduce harassment which increases energetic costs due to locomotion, reduces nutrient intake due to less time spent foraging, and can lead to poorer physiological condition. Reduced physiological condition can lead to lower reproductive output and even higher mortality rates, with the potential to ultimately affect caribou demographics. Caribou affect all trophic levels in the Arctic and the processes that connect them, thus altering caribou demographics could impact the ecology of the region. Broadening the definitions of venomous and toxungenous animals to include hematophagous and endoparasitic insects should not only generate productive collaborations among toxinologists and parasitologists, but will also lead to a deeper understanding of the ecology of toxic secretions and their widespread influence.

Gastrointestinal parasites in reindeer (Rangifer tarandus tarandus): A review focusing on Fennoscandia.

Reindeer (Rangifer tarandus tarandus) are known to host a wide variety of parasites, including those in the gastrointestinal system. Here, we review the current knowledge of the main gastrointestinal parasites of reindeer focusing on northern Fennoscandia, which comprises parts of Finland, Sweden, Norway and Russia. We explore both the historical baseline data for diversity and distribution and recent advancements in our understanding of parasite faunas in reindeer across this region. It is evident that the balance between reindeer and their gastrointestinal parasites, along with the potential for emergent disease in the changing world warrants careful monitoring and further studies.

Gastrointestinal parasites in reindeer (Rangifer tarandus tarandus) calves from Fennoscandia: An epidemiological study.

Reindeer (Rangifer tarandus tarandus) host numerous parasites. Although there is a general knowledge about parasite diversity in reindeer, detailed baseline information about parasitic infections is limited. Detailed knowledge of parasite prevalence and diversity provide a pathway for more targeted parasite control, an increasing need expected in the future. The main aim of our cross-sectional study was to estimate the prevalence of gastrointestinal parasites in semidomesticated reindeer calves. The 480 reindeer calves included in our study were aged 6-7 months, originated from 9 reindeer herding cooperatives in Finland and 1 in Norway, and were slaughtered during September-November 2015 in 10 reindeer slaughterhouses. All the reindeer calves passed meat inspection, and the detected parasitic infections were subclinical. As the reindeer included in this study were young animals intended for slaughter, they had never been administrated any antiparasitic treatment. Assessments of gastrointestinal parasitism among these reindeer calves were based on fecal examination and morphological identification of coccidian oocysts or helminth eggs. Individual fecal samples collected from the rectum of each of the reindeer were examined using a modified McMaster method. Most (78.3%) of the reindeer calves had eggs or oocysts of at least one parasite species in their feces, and more than half (53.5%) had a mixed infection. Strongylid eggs were detected in 75.6%, Eimeria sp. oocysts in 50.6%, Moniezia sp. eggs in 28.1%, Nematodirus sp. eggs in 22.1%, Capillaria sp. eggs in 9.4%, and Trichuris sp. eggs in 0.6% of the samples. The prevalence of gastrointestinal parasites was similar or higher relative to previous estimates from the region; the proportion of reindeer calves shedding strongylid eggs and the proportion of reindeer calves shedding Moniezia sp. eggs had increased. Prevalence varied by geographical region, which may reflect different herding practices or environmental parameters. Higher reindeer density was a risk factor for testing positive for Eimeria sp. oocysts, and the odds of testing positive for Nematodirus sp. eggs were higher if a peroral route was used for antiparasitic treatment in the reindeer herding cooperative. The mean proportion of reindeer estimated to receive antiparasitic treatment in Finland was 86% in 2004-2005 and 91% in 2014-2015. During the historical time frames of current management practices, this routine annual antiparasitic treatment of breeding reindeer has not decreased the prevalence of gastrointestinal parasites in reindeer calves, which can be seen as sentinels or indicators of the infection pressure.

Serological and molecular detection of Toxoplasma gondii in terrestrial and marine wildlife harvested for food in Nunavik, Canada.

BACKGROUND: Toxoplasma gondii, a zoonotic protozoan parasite, infects mammals and birds worldwide. Infection in humans is often asymptomatic, though illnesses can occur in immunocompromised hosts and the fetuses of susceptible women infected during pregnancy. In Nunavik, Canada, 60% of the Inuit population has measurable antibodies against T. gondii. Handling and consumption of wildlife have been identified as risk factors for exposure. Serological evidence of exposure has been reported for wildlife in Nunavik; however, T. gondii has not been detected in wildlife tissues commonly consumed by Inuit. METHODS: We used a magnetic capture DNA extraction and real-time PCR protocol to extract and amplify T. gondii DNA from large quantities of tissues (up to 100 g) of 441 individual animals in Nunavik: 166 ptarmigan (Lagopus lagopus), 156 geese (Branta canadensis and Chen caerulescens), 61 ringed seals (Pusa hispida), 31 caribou (Rangifer tarandus) and 27 walruses (Odobenus rosmarus). RESULTS: DNA from T. gondii was detected in 9% (95% CI: 3-15%) of geese from four communities in western and southern Nunavik, but DNA was not detected in other wildlife species including 20% (95% CI: 12-31%) of ringed seals and 26% (95% CI: 14-43%) of caribou positive on a commercial modified agglutination test (MAT) using thawed heart muscle juice. In geese, tissue parasite burden was highest in heart, followed by brain, breast muscle, liver and gizzard. Serological results did not correlate well with tissue infection status for any wildlife species. CONCLUSIONS: To our knowledge, this is the first report on the detection, quantification, and characterization of DNA of T. gondii (clonal lineage II in one goose) from wildlife harvested for food in Nunavik, which supports the hypothesis that migratory geese can carry T. gondii into Nunavik where feline definitive hosts are rare. This study suggests that direct detection methods may be useful for detection of T. gondii in wildlife harvested for human consumption and provides data needed for a quantitative exposure assessment that will determine the risk of T. gondii exposure for Inuit who harvest and consume geese in Nunavik.

The annual, temporal and spatial pattern of Setaria tundra outbreaks in Finnish reindeer: a mechanistic transmission model approach.

BACKGROUND: In northern Finland (Lapland), reindeer are reared as semi-domesticated animals. The region has a short summer season of 2-3 months, yet reindeer are infected with the mosquito-borne filarioid parasite Setaria tundra. The infection causes peritonitis and perihepatitis, which cause significant economic losses due to reduced body weight of infected animals. The objective of this study was to: (i) describe the spatial and temporal pattern of outbreaks in three different areas across Finnish Lapland; and (ii) construct a temperature-driven mechanistic transmission model to quantify the potential role of temperature on intensity of S. tundra transmission in reindeer. METHODS: We developed a temperature-driven transmission model able to predict the number of S. tundra potentially transmitted from an infectious reindeer. We applied the model to the years 2004-2015, and compared the predictions to the proportion of reindeer whose livers were condemned due to S. tundra infection at the time of slaughter. RESULTS: The mean proportion of liver condemnation increased in reindeer slaughtered in late autumn/winter compared to earlier dates. The outbreaks were geographically clustered each year but there were no fixed foci where outbreaks occurred. Larger outbreaks were recorded in the southern regions of reindeer-herding areas compared to the central or northern parts of Lapland. Our model showed that temperatures never allowed for transmission of more than a single generation of S. tundra each season. In southern (Kuusamo) and central (Sodankylä) Lapland, our model predicted an increasing trend from 1979 to 2015 for both the duration of the effective transmission period of S. tundra (P < 0.001) and for the potential number of L3 S. tundra larvae being transmitted from an infectious reindeer (P < 0.001). CONCLUSIONS: The effective transmission period for S. tundra in reindeer is very short in Lapland, but it increased over the period studied. Only one generation of S. tundra can be transmitted in one season among reindeer in Lapland. Increasing temperatures may facilitate a range expansion and increasing duration of effective transmission period for S. tundra.

Temperature-dependent development and freezing survival of protostrongylid nematodes of Arctic ungulates: implications for transmission.

BACKGROUND: Umingmakstrongylus pallikuukensis and Varestrongylus eleguneniensis are two potentially pathogenic lungworms of caribou and muskoxen in the Canadian Arctic. These parasites are currently undergoing northward range expansion at differential rates. It is hypothesized that their invasion and spread to the Canadian Arctic Archipelago are in part driven by climate warming. However, very little is known regarding their physiological ecology, limiting our ability to parameterize ecological models to test these hypotheses and make meaningful predictions. In this study, the developmental parameters of V. eleguneniensis inside a gastropod intermediate host were determined and freezing survival of U. pallikuukensis and V. eleguneniensis were compared. METHODS: Slug intermediate hosts, Deroceras laeve, were collected from their natural habitat and experimentally infected with first-stage larvae (L1) of V. eleguneniensis. Development of L1 to third-stage larvae (L3) in D. laeve was studied at constant temperature treatments from 8.5 to 24 °C. To determine freezing survival, freshly collected L1 of both parasite species were held in water at subzero temperatures from -10 to -80 °C, and the number of L1 surviving were counted at 2, 7, 30, 90 and 180 days. RESULTS: The lower threshold temperature (T0) below which the larvae of V. eleguneniensis did not develop into L3 was 9.54 °C and the degree-days required for development (DD) was 171.25. Both U. pallikuukensis and V. eleguneniensis showed remarkable freeze tolerance: more than 80% of L1 survived across all temperatures and durations. Larval survival decreased with freezing duration but did not differ between the two species. CONCLUSION: Both U. pallikuukensis and V. eleguneniensis have high freezing survival that allows them to survive severe Arctic winters. The higher T0 and DD of V. eleguneniensis compared to U. pallikuukensis may contribute to the comparatively slower range expansion of the former. Our study advances knowledge of Arctic parasitology and provides ecological and physiological data that can be useful for parameterizing ecological models.

Molecular taxonomy and subgeneric classification of tapeworms of the genus Moniezia Blanchard, 1891 (Cestoda, Anoplocephalidae) in northern cervids (Alces and Rangifer).

Phylogenetic relationships of tapeworms of the genus Moniezia Blanchard, 1891 (Cestoda, Anoplocephalidae) parasitizing the Eurasian elk Alces alces, the moose A. americanus and the reindeer/caribou Rangifer tarandus (Cervidae) were studied using DNA sequences of two mitochondrial genes (cox1 and nad1). Several isolates from domestic ruminants, representing Moniezia expansa (Rudolphi, 1810) sensu lato and M. benedeni (Moniez, 1879) sensu lato, and one unidentified isolate from an African antelope, were also included in the analysis. Both genes identified the same six species of Moniezia, but interspecific phylogenetic relationships were better resolved by the nad1 data. The six species of Moniezia comprised two main clades: clade 1 that originates in bovids, with subsequent colonization of northern cervids in Eurasia, and clade 2 that originates in northern cervids, with subsequent specific divergence within these hosts. Clade 2 has a Holarctic distribution. None of the Moniezia specimens in Alces and Rangifer was conspecific with the species in domestic ruminants, suggesting that the custom of identifying Moniezia spp. in northern cervids either as M. expansa or M. benedeni is incorrect. At least two of the species parasitizing Alces and Rangifer have not been previously recognized. These findings challenge the results of all previous studies concerning the diversity and ecology of Moniezia spp. in northern cervids. The traditional classification into three subgenera (Moniezia Blanchard, 1891, Blanchariezia Skrjabin & Schultz, 1937 and Baeriezia Skrjabin & Schultz, 1937), based on the presence and type of interproglottidal glands, conflicts with the currently observed molecular phylogenetic relationships within the genus Moniezia.

INTESTINAL HISTOPLASMOSIS IN A CAPTIVE REINDEER (RANGIFER TARANDUS), MISSOURI, USA.

An infection with Histoplasma capsulatum was diagnosed in a farmed reindeer in Missouri, an endemic area for histoplasmosis, localized in the intestine. The intrahistiocytic organisms were identified in tissue sections using histologic methods and confirmed by immunohistochemistry. This is the first report of histoplasmosis in a reindeer or in any deer species.

Giardia and Cryptosporidium infections in neonatal reindeer calves: Relation to the acute phase response.

This longitudinal observational study was conducted to investigate the spontaneous effect of Giardia and Cryptosporidium infections on acute phase response (APR) in reindeer calves (Rangifer tarandus tarandus) in Finnish Lapland. Serum (n=609) and faecal samples (n=366) were collected from 54 reindeer calves aged zero to 33days. The samples were analysed for Giardia, Cryptosporidium, acute phase proteins (APP) and γ-globulins. Linear regression models were used to investigate associations of early Giardia infection (before 12days of life) with the response of APPs and acquiring of passive immunity. Giardia was detected in 100% and Cryptosporidium in 23% of calves. There was a negative association between early Giardia infection and γ-globulin concentrations (p=0.032) and a positive association with serum amyloid A (SAA) concentrations (p=0.042). The results suggest a protective effect of colostrum against Giardia infection and that early infection may induce activation of APR.

Human myiasis caused by the reindeer warble fly, Hypoderma tarandi, case series from Norway, 2011 to 2016.

Hypoderma tarandi causes myiasis in reindeer and caribou (Rangifer tarandus spp.) in most northern hemisphere regions where these animals live. We report a series of 39 human myiasis cases caused by H. tarandi in Norway from 2011 to 2016. Thirty-two were residents of Finnmark, the northernmost county of Norway, one a visitor to Finnmark, and six lived in other counties of Norway where reindeer live. Clinical manifestations involved migratory dermal swellings of the face and head, enlargement of regional lymph nodes, and periorbital oedema, with or without eosinophilia. Most cases of human myiasis are seen in tropical and subtropical countries, and in tourists returning from such areas. Our findings demonstrate that myiasis caused by H. tarandi is more common than previously thought. Healthcare professionals in regions where there is a likelihood of human infestation with H. tarandi (regions populated by reindeer), or treating returning travellers, should be aware of the condition. All clinicians are advised to obtain a detailed travel history when assessing patients with migratory dermal swellings. On clinical suspicion, ivermectin should be given to prevent larval invasion of the eye (ophthalmomyiasis). Since H. tarandi oviposits on hair, we suggest wearing a hat as a prevention measure.

Experimental Life-Cycle of Varestrongylus eleguneniensis (Nematoda: Protostrongylidae) in a Captive Reindeer (Rangifer tarandus tarandus) and a Muskox (Ovibos moschatus moschatus).

The life-cycle of a recently described protostrongylid lungworm, Varestrongylus eleguneniensis, which infects caribou, muskoxen, and moose from Arctic and boreal regions of North America, was completed experimentally for the first time. A native North American slug species, Deroceras laeve, was infected with the first-stage larvae (L1) isolated from the feces of wild muskoxen to generate third-stage larvae (L3). These were administered to a captive reindeer calf (250 L3) and an adult captive muskox (380 L3). The prepatent periods for the reindeer and muskox were 56 and 72 days, respectively. Patency lasted for only 19 days in the reindeer, and fecal larval counts were very low (0.09-1.53 larvae per gram of feces). Patency in the muskox was at least 210 days, and likely over 653 days, and the fecal larval counts were higher (0.06-17.8 larvae per gram of feces). This work provides the first experimental completion of the life-cycle of V. eleguneniensis.

A new Eimeria species (Protozoa: Eimeriidae) from caribou in Ameralik, West Greenland.

Fecal samples of 11 calves shot in the Ameralik area, West Greenland, in August-September 2014 were examined for coccidian parasites. The calves belonged to a population of interbreeding indigenous caribou Rangifer tarandus groenlandicus and feral semi-domestic Norwegian reindeer Rangifer tarandus tarandus. Two coccidian species were found: Eimeria rangiferis and a coccidium that was identified and described as a new species. The latter's sporulated oocyst is spherical or slightly subspherical. Average size is 25.6 × 24.8 µm. The oocyst has two distinct walls. Wall thickness is ∼1.4 µm. The unicolored outer wall is brown, the inner wall is dark gray. The oocysts contain a small polar granule but are devoid of a microphyle. The oocysts enclose four ovoid-shaped sporocysts with a rounded end opposite to the Stieda body. The average size of sporocysts is 15.2 × 7.8 µm. Sporocysts contain a granular sporocyst residuum that forms a spherical cluster between the sporocysts, one large refractile body is present in each sporozoite. The spherical form easily distinguishes oocysts of the new species from the seven previously described eimerid species in R. tarandus. This is the first eimerid described as a new species to the sciences from caribou in the Nearctic.

Occurrence of Babesia species in captive reindeer (Rangifer tarandus) in Germany.

Two cases of acute babesiosis in captive reindeer (Rangifer tarandus) in two German zoos in 2009 and 2012 triggered this study to investigate the occurrence and species diversity of Babesia parasites infecting reindeer in different zoos and deer parks in Germany. Between June and December 2013, blood samples were taken from 123 clinically inapparent reindeer from 16 different facilities. Samples were tested for the presence of Babesia species DNA by conventional PCR and sequence analysis of part of the 18S rRNA gene. Also, Giemsa-stained smears of reindeer blood samples were examined for parasitaemia by light microscopy. The overall PCR-prevalence in blood samples was 23.6% (n=29). Comparison of sequenced amplicons with GenBank entries possibly revealed up to five different Babesia species: B. venatorum (n=19), B. capreoli (n=2) and B. capreoli-like (n=4), B. odocoilei-like (n=2) and B. divergens (n=1), while one sample turned out to be a Theileria sp. Out of the 16 facilities in the study, 12 housed at least one positive animal. In Giemsa-stained blood smears, intra-erythrocytic Babesia parasites were detected in samples of three reindeer from three locations. The high prevalence of Babesia infections implicates babesiosis to be a relevant infectious disease threat for captive reindeer in Germany. Consequently, reindeer with clinical signs compatible to those of acute babesiosis should either be tested for the presence of Babesia spp. DNA or blood smears should be examined for parasitaemia.