Effect of gastro-intestinal nematode infection on sheep performance: a systematic review and meta-analysis

Background: Gastrointestinal nematode (GIN) infections are common in domestic sheep and impact directly and indirectly on the health of infected animals as well as on the associated economic production. In this study, we aim at summarizing the current knowledge on the influence of GIN infections on sheep production by conducting a systematic review. A subsequent meta-analysis of relevant studies was performed to provide an estimate of the effect of GIN infections on weight gain, wool production and milk yield. Methods: A literature search was performed on the CAB, Pubmed and Web of Science database for the period 1960–2012. Inclusion criteria were: 1) Measurement of at least one production parameter. 2) Comparison between groups of sheep with different nematode burdens. 3) Same conditions regarding all aspects except parasite burden between groups. 4) Quantitative measurements of one or more production traits. Results: Altogether, 88 studies describing 218 trials were included in this review. The majority of studies (86 %) reported that GIN infections had a negative effect on production but this was reported to be statistically significant in only 43 % of the studies. Meta-analysis indicated that performances of sheep infected with nematodes was 85, 90 and 78 % of the performance in uninfected individuals for weight gain, wool production and milk yield respectively. Our results suggest a possible reporting bias or small study effect for the estimation of the impact of GIN infections on weight gain. Finally, a general linear model provided an estimate for the decrease in weight gain in relation to the increase in faecal egg count of nematodes. Conclusion: This study underlines the importance of GIN infections for sheep production and highlights the need to improve parasite management in sheep, in particular in face of challenges such as anthelmintic resistance. Keywords: Sheep, Gastro-intestinal nematodes, Impact, Weight, Wool, Milk, Productio

Is the development of infectious keratoconjunctivitis in Alpine ibex and Alpine chamois influenced by topographic features?

Infectious keratoconjunctivitis (IKC) caused by Mycoplasma conjunctivae is a widespread ocular affection of free-ranging Caprinae in the Alpine arc. Along with host and pathogen characteristics, it has been hypothesized that environmental factors such as UV light are involved in the onset and course of the disease. This study aimed at evaluating the role of topographic features as predisposing or aggravating factors for IKC in Alpine chamois (Rupicapra rupicapra rupicapra) and Alpine ibex (Capra ibex ibex). Geospatial analysis was performed to assess the effect of aspect (northness) and elevation on the severity of the disease as well as on the mycoplasmal load in the eyes of affected animals, using data from 723 ibex and chamois (583 healthy animals, 105 IKC-affected animals, and 35 asymptomatic carriers of M. conjunctivae), all sampled in the Swiss Alps between 2008 and 2010. An influence of northness was not found, except that ibex with moderate and severe signs of IKC seem to prefer more north-oriented slopes than individuals without corneal lesions, possibly hinting at a sunlight sensitivity consequent to the disease. In contrast, results suggest that elevation influences the disease course in both ibex and chamois, which could be due to altitude-associated environmental conditions such as UV radiation, cold, and dryness. The results of this study support the hypothesis that environmental factors may play a role in the pathogenesis of IK

Alpine ibex ( Capra i: ibex ) is not a reservoir for chlamydial infections of domestic ruminants and humans

Chlamydophila (C.) abortus is the most common infectious abortigenic agent in small domestic ruminants in Switzerland. In contrast, the knowledge about chlamydiae in wild ruminants is scarce. As interactions between livestock and Alpine ibex (Capra i. ibex) occur on alpine pastures, the question raises if wild ruminants could play a role as carriers of chlamydiae. Thus, we investigated the prevalence of chlamydiae in Alpine ibex in Switzerland. In total, 624 sera, 676 eye swabs, 84 organ samples and 51 faecal samples from 664 ibex were investigated. Serum samples were tested by two commercial ELISA kits specific for C. abortus. Eye swabs, organs and faecal samples were examined by a Chlamydiaceae-specific real-time polymerase chain reaction (PCR). Positive cases were further investigated by the ArrayTube (AT) microarray method for chlamydial species determination. Of 624 serum samples investigated, 612 animals were negative, whereas nine sera (1.5%) reacted positively in one of the two tests and three sera showed an inconclusive result. Eye swabs of seven out of 412 ibex (1.7%) were tested positive for Chlamydiaceae by real-time PCR. By AT microarray, Chlamydophila (C.) pecorum was identified in two animals, Chlamydophila (C.) pneumoniae was detected in one animal and a mixed infection with C. abortus and C. pecorum was found in four animals. Organs and faecal samples were all negative by real-time PCR analysis. In summary, we conclude that C. abortus is not a common infectious agent in the Swiss ibex population. To our knowledge, this is the first description of C. pneumoniae in ibex. Further studies are necessary to elucidate the situation in other species of wild ruminants as chamois (Rupicapra r. rupicapra), red deer (Cervus elaphus) and roe deer (Capreolus c. capreolus) in Switzerlan

Surveillance for Zoonotic Pathogens and Inuit Qaujimajatuqangit of Ringed Seals (nattiit) (Pusa hispida) in Frobisher Bay and Eclipse Sound, Nunavut, Canada

Ringed seals (Pusa hispida) (nattiq (s.), nattiit (pl.) [Inuktut]) provide an important food staple for Nunavummiut (Indigenous residents of Nunavut). We studied the health of nattiit harvested by hunters from Baffin Island, Nunavut, via Inuit Qaujimajatuqangit and veterinary science. We conducted serological surveys and polymerase chain reaction (PCR) for select zoonotic pathogens, including Brucella spp., Erysipelothrix rhusiopathiae, Leptospira interrogans and Toxoplasma gondii, in 55 nattiit from Frobisher Bay (FB) and 58 nattiit from Eclipse Sound (ES). We used a digestion assay to determine the presence of Trichinella spp. larvae in muscle samples from these seals. We conducted interviews with nine Local Knowledge Holders (LKHs) from Iqaluit (FB) and nine from Pond Inlet (ES) to gather their observations about nattiq health. The hunters evaluate nattiq health through a combination of behavior, nutritional condition, and appearance of skin and organs. They rarely observed severely ill nattiit. Hunters from ES but not from FB observed declining nattiit population numbers. In both regions, they observed increased numbers of harp seals (Phoca groenlandica). Frequencies of natural exposure among nattiit from FB and ES, based on seroprevalence, were 20.5% and 37% for Brucella spp., 25% and 11% for E. rhusiopathiae, 93% and 100% for L. interrogans, and 10% and 27% for T. gondii, respectively; PCR was negative for these pathogens in organs and tissues of seropositive animals. We did not detect larvae of Trichinella spp. Knowledge and experience from the LKHs in assessing nattiq health, complemented by negative findings from direct detection methods, provide reassurance about the safety of nattiit as country food, despite their exposure to some zoonotic pathogens in their natural environment.Les phoques annelés (Pusa hispida) (nattiq (s.), nattiit (pl.) [en inuktut]) constituent une source de nourriture importante pour les Nunavummiut (habitants autochtones du Nunavut). Nous avons étudié l’état de santé des nattiit collectés par les chasseurs de l’île de Baffin, au Nunavut à l’aide de l’Inuit Qaujimajatuqangit et de la science vétérinaire. La sérologie et l’amplification en chaîne par polymérase (PCR) ont été employées pour étudier certains pathogènes susceptibles de causer une zoonose, dont Brucella spp., Erysipelothrix rhusiopathiae, Leptospira interrogans et Toxoplasma gondii, chez 55 nattiit de la baie Frobisher (BF) et 58 nattiit du détroit d’Éclipse (ES). Un test de digestion a été utilisé pour déterminer la présence de larves de Trichinella spp. dans des échantillons de muscle de ces phoques. Nous avons interviewé neuf détenteurs de savoirs locaux (DSL) d’Iqaluit (BF) et neuf DSL de Pond Inlet (ES) afin de recueillir leurs observations sur l’état de santé des nattiit. Les chasseurs évaluent l’état de santé des nattiit à partir de leur comportement, de leur état nutritionnel ainsi que de l’apparence de leur peau et de leurs organes. Ils ont rarement vu des nattiit sévèrement malades. Les chasseurs d’ES ont observé un déclin de la population de nattiit, ce qui n’a pas été le cas des chasseurs de la BF. Dans les deux régions, ils ont observé une augmentation du nombre de phoques du Groenland (Phoca groenlandica). Les fréquences d’exposition naturelle parmi les nattiit de la BF et d’ES, basées sur la séroprévalence, étaient de 20,5 % et de 37 % pour Brucella spp., de 25 % et de 11 % pour E. rhusiopathiae, de 93 % et de 100 % pour L. interrogans et de 10 % et de 27 % pour T. gondii, respectivement. La présence de ces pathogènes dans les tissus et organes d’animaux séropositifs n’a pas été détectée par PCR. Des larves de Trichinella spp. n’ont pas été détectées. Le savoir et l’expérience des DSL pour déterminer l’état de santé des nattiit ainsi que les résultats négatifs obtenus des méthodes de détection directes fournissent une preuve de la salubrité des nattiit comme source de nourriture traditionnelle, malgré le fait qu’ils soient exposés à certains agents pathogènes zoonotiques dans leur milieu naturel

Muskox Health Ecology Symposium 2016: Gathering to Share Knowledge on Umingmak in a Time of Rapid Change

The Muskox, Ovibos moschatus, also known as Umingmak ‘the Bearded One,’ is a taxonomically unique, cold-adapted, ice-age survivor. Originally native to Canada and Greenland, it has established a circum-Arctic distribution via introduced populations. As a key resident herbivore in northern ecosystems, the muskox has importance that should not be underestimated. Muskoxen play an important role in the cultural identity of Arctic Indigenous peoples and provide a healthy source of country food. More recently, recognition of the economic potential of the species through tourism, sport hunting, and the traditional sale of handicrafts has generated renewed interest in muskoxen and their ecology. Recent documentation of diseases, including several zoonoses, regional mortality events, and population declines have highlighted knowledge gaps in both our understanding of the drivers of muskox population fluctuations and the potential sensitivity of this species to a rapidly changing climate (Kutz et al., 2013, 2015; Handeland et al., 2014; Ytrehus et al., 2015; Tomaselli et al., 2016c; Afema et al., 2017)

Additional file 1: of Effect of gastro-intestinal nematode infection on sheep performance: a systematic review and meta-analysis

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Is the development of infectious keratoconjunctivitis in Alpine ibex and Alpine chamois influenced by topographic features?

Infectious keratoconjunctivitis (IKC) caused by Mycoplasma conjunctivae is a widespread ocular affection of free-ranging Caprinae in the Alpine arc. Along with host and pathogen characteristics, it has been hypothesized that environmental factors such as UV light are involved in the onset and course of the disease. This study aimed at evaluating the role of topographic features as predisposing or aggravating factors for IKC in Alpine chamois (Rupicapra rupicapra rupicapra) and Alpine ibex (Capra ibex ibex). Geospatial analysis was performed to assess the effect of aspect (northness) and elevation on the severity of the disease as well as on the mycoplasmal load in the eyes of affected animals, using data from 723 ibex and chamois (583 healthy animals, 105 IKC-affected animals, and 35 asymptomatic carriers of M. conjunctivae), all sampled in the Swiss Alps between 2008 and 2010. An influence of northness was not found, except that ibex with moderate and severe signs of IKC seem to prefer more north-oriented slopes than individuals without corneal lesions, possibly hinting at a sunlight sensitivity consequent to the disease. In contrast, results suggest that elevation influences the disease course in both ibex and chamois, which could be due to altitude-associated environmental conditions such as UV radiation, cold, and dryness. The results of this study support the hypothesis that environmental factors may play a role in the pathogenesis of IKC

Occurrence, quantification, and genotyping of Mycoplasma conjunctivae in wild Caprinae with and without infectious keratoconjunctivitis

Mycoplasma conjunctivae, the causative agent of infectious keratoconjunctivitis (IKC), was recently detected in asymptomatic Alpine ibex (Capra ibex ibex). This suggested that an external source of infection may not be required for an IKC outbreak in wildlife but might be initiated by healthy carriers, which contradicted previous serologic investigations in chamois. Our aims were to 1) assess the prevalence of M. conjunctivae among asymptomatic ibex and Alpine chamois (Rupicapra rupicapra rupicapra) and its frequency in IKC-affected animals, 2) determine mycoplasma loads in different disease stages, and 3) characterize the M. conjunctivae strains involved. Eye swabs from 654 asymptomatic and 204 symptomatic animals were collected in diverse Swiss regions between 2008 and 2010, and tested by TaqMan real-time PCR. Data analysis was performed considering various patterns of IKC occurrence in the respective sampling regions. Strains from 24 animals were compared by cluster analysis. Prevalence of M. conjunctivae was 5.6% (95% confidence interval [CI]: 3.7-8.1%) in asymptomatic ibex and 5.8% (CI: 3.0-9.9%) in asymptomatic chamois, with significant differences between years and regions in both species. Detection frequency in symptomatic animals was significantly higher during IKC outbreaks than in nonepidemic situations (i.e., regular but low incidence or sporadic occurrence). Mycoplasma load was significantly lower in eyes from healthy carriers and animals with mild signs than from animals with moderate and severe signs. Although some strains were found in both asymptomatic and diseased animals of the same species, others apparently differed in their pathogenic potential depending on the infected species. Overall, we found a widespread occurrence of M. conjunctivae in wild Caprinae with and without IKC signs. Our results confirm the central role of M. conjunctivae in outbreaks but suggest that other infectious agents may be involved in IKC cases in nonepidemic situations. Additionally, presence and severity of signs are related to the quantity of M. conjunctivae in the eyes rather than to the strain. We propose that individual or environmental factors influence the clinical expression of the disease and that persistence of M. conjunctivae in populations of wild Caprinae cannot be excluded