In vitro acaricidal activity of several natural products against ibex-derived Sarcoptes scabiei.

In this study we analysed the effect of the temperature, diverse strains of Bacillus thuringiensis, Lysinibacillus sphaericus and nanoformulations with essential plant oils (EONP) on the survival of Sarcoptes scabiei mites derived from naturally-infested Iberian ibex (Capra pyrenaica). In general, mites maintained at 12ºC survived more than those maintained at 35ºC (40.7 hr and 31.2 hr, respectively). Mites with no treatment survived 27.6 h on average. Mites treated with B. thuringiensis serovar. konkukian and geranium EONP showed significant reduction in their survival. Despite the fact that these agents seem to be promising candidates for controlling sarcoptic mange in the field, further research is still needed to get stable, efficient and eco-friendly acaricides.

Mapping the risk of exposure to Crimean-Congo haemorrhagic fever virus in the Iberian Peninsula using Eurasian wild boar (Sus scrofa) as a model.

Crimean-Congo haemorrhagic fever (CCHF) virus (CCHFV) is a tick-borne zoonotic pathogen that can cause a lethal haemorrhagic disease in humans. Although the virus appears to be endemically established in the Iberian Peninsula, CCHF is an emerging disease in Spain. Clinical signs of CCHFV infection are mainly manifested in humans, but the virus replicates in several animal species. Understanding the determinants of CCHFV exposure risk from animal models is essential to predicting high-risk exposure hotspots for public health action. With this objective in mind, we designed a cross-sectional study of Eurasian wild boar (Sus scrofa) in Spain and Portugal. The study analysed 5,291 sera collected between 2006 and 2022 from 90 wild boar populations with a specific double-antigen ELISA to estimate CCHFV serum prevalence and identify the main determinants of exposure probability. To do so, we statistically modelled exposure risk with host- and environment-related predictors and spatially projected it at a 10 × 10 km square resolution at the scale of the Iberian Peninsula to map foci of infection risk. Fifty-seven (63.3 %) of the 90 populations had at least one seropositive animal, with seroprevalence ranging from 0.0 to 88.2 %. Anti-CCHFV antibodies were found in 1,026 of 5,291 wild boar (19.4 %; 95 % confidence interval: 18.3-20.5 %), with highest exposure rates in southwestern Iberia. The most relevant predictors of virus exposure risk were wild boar abundance, local rainfall regime, shrub cover, winter air temperature and soil temperature variation. The spatial projection of the best-fit model identified high-risk foci as occurring in most of western and southwestern Iberia and identified recently confirmed risk foci in eastern Spain. The results of the study demonstrate that serological surveys of CCHFV vector hosts are a powerful, robust and highly informative tool for public health authorities to take action to prevent human cases of CCHF in enzootic and emergency settings.

Co-infection patterns in the ectoparasitic community affecting the Iberian ibex Capra pyrenaica.

BACKGROUND: Sarcoptic mange is one of the main parasitic diseases affecting the Iberian ibex Capra pyrenaica. Scabietic animals suffer a decline in body condition and reproductive fitness and in severe cases may die. Although several previous studies of the pathology of this disease and the physiological changes it produces in ibex have been carried out in recent years, our knowledge of the relationship between Sarcoptes scabiei and other ectoparasites of this host is still limited. METHODS: We analysed 430 Iberian ibex skin samples. Ectoparasites were removed, counted and identified. Mite (S. scabiei) numbers were obtained after digesting the skin samples in a 5% KOH solution. We modelled mite numbers in terms of host sex and age, site, year, season and the presence of other ectoparasites such as ticks and lice using generalized linear mixed models (GLMMs) and ectoparasite co-occurrence patterns using two different models: the probabilistic model species co-occurrence and the generalized linear latent variable model (GLLVM). RESULTS: The ectoparasite community was mainly composed of S. scabiei, six ticks (Haemaphysalis sulcata, Haemaphysalis punctata, Rhipicephalus bursa, Rhipicephalus turanicus, Dermacentor marginatus and Ixodes ricinus) and two lice (Bovicola crassipes and Linognathus stenopsis). Adult male ibex harboured more mites than females. Mite numbers varied greatly spatially and seasonally and increased with the presence of other parasites. Some positive co-occurrence relationships between pairs of different ectoparasites were observed, particularly between ticks. The presence of S. scabiei negatively affected lice and H. sulcata numbers. CONCLUSIONS: Sarcoptic mange has spread above all in ibex populations in and around the Mediterranean Basin, where it is now found in almost a third of its host's range. Mite numbers varied seasonally and spatially and were higher in male hosts. The presence of S. scabiei had a negative effect on lice numbers but favoured the presence of ticks.

Individual stress responses to Sarcoptes scabiei infestation in Iberian ibex, Capra pyrenaica.

In this study we have monitored the stress of Iberian ibex at individual level within the course of an experimental infection with Sarcoptes scabiei mites. For this purpose we have measured faecal 11-ketoetiocholanolone (11-k) using high-performance liquid chromatography coupled with tandem mass spectrometry (HPLC-MS/MS). We used linear mixed models to explore the effects of host sex and age, clinic (mange status) and time (number of days post-infection) on the concentration of faecal 11-k. The most parsimonious model included clinic, time and host age, which explained 76.6% of the variance of the response variable. Moreover, the concentration of faecal 11-k varied greatly between individuals. Our results evidence the stressor nature of the disease and highlight the negative effects on hosts due to cortisol release and activity.

Characterizing the growth of Sarcoptes scabiei infrapopulations.

During the course of parasitic disease infestations, parasite population sizes change at both individual host (infrapopulation) and host population (metapopulation) levels. However, most studies only report epidemiological values for specific locations and times. In this study we analysed the dynamics of several Sarcoptes scabiei infrapopulations from experimentally infested Iberian ibex, Capra pyrenaica. We obtained mite counts by digesting small skin biopsies, which we compared with indices obtained from histopathological analyses performed on adjacent skin biopsies. We obtained the finite growth rate and the daily growth rate for the mite infrapopulations: mean ± SE = 11.53 ± 10.17 and 0.10 ± 0.08 mites/day, respectively. Mite counts derived from skin sample digestion did not correlate with the histological mite indices obtained from adjacent skin biopsies. At a metapopulational level, both indices of mite abundance were modelled using GLMMs and the factors influencing their variation are analysed and discussed. Our results suggest that mites are not distributed uniformly over the whole area of the skin lesion. Therefore, direct diagnoses of mange and mite counts could be inaccurate if only small skin samples are used.

Sarcoptes scabiei alters follicular dynamics in female Iberian ibex through a reduction in body weight.

Normal development of the ovarian cycle is a key factor in ensuring female reproductive success. Sarcoptes scabiei has been shown to induce changes in host physiology, although the effects of this mite on the female reproductive cycle are still unknown. In an attempt to clarify this issue, the number of ovarian structures (primary follicles, secondary follicles, Graaf follicles, corpus luteum and corpus albicans) in female Iberian ibex (Capra pyrenaica) affected by sarcoptic mange was explored by histological analysis of samples taken from 102 females selectively harvested in the Sierra Nevada Natural Space, southern Spain. The effect of mange status, body weight (corrected for age), age and year of sampling on the number of ovarian structures was assessed using generalized linear models. Our results provide evidence that sarcoptic mange alters follicular dynamics through a reduction in host body weight, whose main consequences are noted in follicular maturation and ovulatory capacity.

Molecular Analyses Reveal Unexpected Genetic Structure in Iberian Ibex Populations.

BACKGROUND: Genetic differentiation in historically connected populations could be the result of genetic drift or adaptation, two processes that imply a need for differing strategies in population management. The aim of our study was to use neutral genetic markers to characterize C. pyrenaica populations genetically and examine results in terms of (i) demographic history, (ii) subspecific classification and (iii) the implications for the management of Iberian ibex. METHODOLOGY/PRINCIPAL FINDINGS: We used 30 neutral microsatellite markers from 333 Iberian ibex to explore genetic diversity in the three main Iberian ibex populations in Spain corresponding to the two persisting subspecies (victoria and hispanica). Our molecular analyses detected recent genetic bottlenecks in all the studied populations, a finding that coincides with the documented demographic decline in C. pyrenaica in recent decades. Genetic divergence between the two C. pyrenaica subspecies (hispanica and victoriae) was substantial (FST between 0.39 and 0.47). Unexpectedly, we found similarly high genetic differentiation between two populations (Sierra Nevada and Maestrazgo) belonging to the subspecies hispanica. The genetic pattern identified in our study could be the result of strong genetic drift due to the severe genetic bottlenecks in the studied populations, caused in turn by the progressive destruction of natural habitat, disease epidemics and/or uncontrolled hunting. CONCLUSIONS: Previous Capra pyrenaica conservation decision-making was based on the clear distinction between the two subspecies (victoriae and hispanica); yet our paper raises questions about the usefulness for conservation plans of the distinction between these subspecies.

Sarcoptes scabiei infestation does not alter the stability of ectoparasite communities.

BACKGROUND: The host represents a heterogeneous ecosystem where multiple parasite species co-occur and interact with each other for space and resources. Although these interactions may rule the features of an infracommunity and may shape the infracommunity response to external perturbations, the resilience of ectoparasite communities to new infestations remains poorly explored. METHODS: We analysed the composition of the ectoparasite communities found on 214 individual Iberian ibexes (Capra pyrenaica) inhabiting the Sierra Nevada Natural Space, southern Spain. Using classification and regression trees, we explored how the presence of Sarcoptes scabiei (a highly contagious mite), the off-host environment and the host sex govern the prevalence and abundance of lice and ticks. Null model analysis was applied to assess the impact of S. scabiei on the structure of the ectoparasite communities. RESULTS: Our results suggest that S. scabiei infestation acts in tandem with off-host environment and host sex to define the prevalence and abundance of lice and ticks. We also provided evidence for differences in species co-occurrence only at the early stages of S. scabiei infestation. Regarding species diversity, we recorded that ectoparasite communities in scabietic ibexes reached a high richness faster than those in healthy individuals. CONCLUSIONS: Even though we show that ectoparasite burden is correlated with S. scabiei infestation, off-host environment and host sex, the species response to S. scabiei infestation and climate seem to be highly variable and influenced by ectoparasite life-history traits. Ectoparasite communities also appear resilient to perturbations which is in agreement with what was previously reported for endoparasites. Future refinement of sample collection and the incorporation of ecological and epidemiological-related variables may allow us to establish causal effects and deepen the knowledge about the mechanisms and consequences of ectoparasite interactions.

Lead and cadmium in wild boar (Sus scrofa) in the Sierra Nevada Natural Space (southern Spain).

The aims of the present study were to investigate Pb and Cd levels in tissues of wild boar (Sus scrofa) from the Sierra Nevada Natural Space (SNNS) (southern Spain). Heavy metal concentrations in livers, kidneys and bones from 111 animals were determined by inductively coupled plasma optical emission spectrometry (ICP-OES). Bones and kidneys were the most Pb- and Cd-contaminated tissues, respectively; Cd concentrations were 5.6 times higher in kidneys than in livers. This is the first biomonitoring study of these pollutants in wild boar tissues in the SNNS, and findings indicate that this population is chronically exposed to these heavy metals. The detected Pb and Cd concentrations were lower than those found in many studies performed in Europe on the same species.

Sex-biased severity of sarcoptic mange at the same biological cost in a sexually dimorphic ungulate.

BACKGROUND: In sexually dimorphic species, male susceptibility to parasite infection and mortality is frequently higher than in females. The Iberian ibex (Capra pyrenaica) is a sexually dimorphic mountain ungulate endemic to the Iberian Peninsula commonly affected by sarcoptic mange, a chronic catabolic skin disease caused by Sarcoptes scabiei. Since 1992, sarcoptic mange affects the Iberian ibex population of the Sierra Nevada Natural Space (SNNS). This study aims at exploring whether mange severity, in terms of prevalence and its effects on body condition, is male-biased in Iberian ibex. FINDINGS: One thousand and seventy-one adult Iberian ibexes (439 females and 632 males) were randomly shot-harvested in the SNNS from May 1995 to February 2008. Sarcoptic mange stage was classified as healthy, mildly infected or severely infected. Sex-biased prevalence of severe mange was evaluated by a Chi-square test whereas the interaction between mange severity and sex on body condition was assessed by additive models. Among scabietic individuals, the prevalence of severely affected males was 1.29 times higher than in females. On the other hand, both sexes were not able to take profit of a higher availability of seasonal food resources when sarcoptic, particularly in the severe stages. CONCLUSIONS: Sarcoptic mange severity is male-biased in Iberian ibex, though not mange effects on body condition. Behavioural, immunological and physiological characteristics of males may contribute to this partial sex-biased susceptibility to sarcoptic mange.

Sarcoptic mange breaks up bottom-up regulation of body condition in a large herbivore population.

BACKGROUND: Both parasitic load and resource availability can impact individual fitness, yet little is known about the interplay between these parameters in shaping body condition, a key determinant of fitness in wild mammals inhabiting seasonal environments. METHODS: Using partial least square regressions (PLSR), we explored how temporal variation in climatic conditions, vegetation dynamics and sarcoptic mange (Sarcoptes scabiei) severity impacted body condition of 473 Iberian ibexes (Capra pyrenaica) harvested between 1995 and 2008 in the highly seasonal Alpine ecosystem of Sierra Nevada Natural Space (SNNS), southern Spain. RESULTS: Bottom-up regulation was found to only occur in healthy ibexes; the condition of infected ibexes was independent of primary productivity and snow cover. No link between ibex abundance and ibex body condition could be established when only considering infected individuals. CONCLUSIONS: The pernicious effects of mange on Iberian ibexes overcome the benefits of favorable environmental conditions. Even though the increase in primary production exerts a positive effect on the body condition of healthy ibexes, the scabietic individuals do not derive any advantage from increased resource availability. Further applied research coupled with continuous sanitary surveillance are needed to address remaining knowledge gaps associated with the transmission dynamics and management of sarcoptic mange in free-living populations.

Molecular characterization of bot flies, Oestrus spp., (Diptera, Oestridae), from domestic and wild Bovidae hosts.

The identification of Oestrus spp. larvae from Bovidae hosts is a difficult task due to the great morphological similarity between species. The lack of unambiguous identification criteria could have also serious epidemiological implications since domestic and wild hosts are sympatric in many natural areas. In order to accurately identify the Oestrus parasitizing hosts, we characterized two different genetic markers, 28S (rRNA) and COI, in larvae collected from domestic sheep and goats, European mouflon and Iberian ibex. Our sequence analyses demonstrate that all samples, except those from Iberian ibex, greatly resembles O. ovis and so we conclude that the species parasitizing this ibex is not O. ovis. Further studies will be needed to confirm whether it is in fact O. caucasicus, as previously suggested, or even a new species.

Distinguishing disease effects from environmental effects in a mountain ungulate: seasonal variation in body weight, hematology, and serum chemistry among Iberian ibex (Capra pyrenaica) affected by sarcoptic mange.

Our study focuses on the Iberian ibex (Capra pyrenaica) from the Sierra Nevada Natural Space (southern Spain), where sarcoptic mange is an endemic disease and animals are affected by a highly seasonal environment. Our aim was to distinguish between disease and environmental influences on seasonal variation in body weight, hematology, and serum biochemistry in Iberian ibex. We sampled 136 chemically immobilized male ibexes. The single effect of mange influenced hemoglobin, hematocrit, mean corpuscular volume, leukocytes, band neutrophils, monocytes, cholesterol, urea, creatine, and aspartate aminotransferase. Both mange and the period of the year also affected values of mean corpuscular hemoglobin, mean corpuscular hemoglobin concentration, neutrophils, glucose, and serum proteins. Scabietic animals showed a marked reduction in body weight (21.4 kg on average), which was more pronounced in winter. These results reveal that 1) infested animals are anemic, 2) secondary infections likely occur, and 3) sarcoptic mange is catabolic.

Long-term monitoring of 10 selected pathogens in wild boar (Sus scrofa) in Sierra Nevada National Park, southern Spain.

Wild boar (Sus scrofa) populations are increasing in the Iberian Peninsula, and population management must include disease management and control. In this study, the epidemiology of 10 selected pathogens (Aujeszky's disease virus - ADV, porcine reproductive and respiratory syndrome virus - PRRSV, porcine influenza virus, porcine circovirus, porcine parvovirus, Erysipelotrix rhusiopathiae, Leptospira pomona, Chlamydia/Chlamydiaceae sp., Salmonella sp. and Mycobacterium bovis) in the wild boar population in Sierra Nevada National Park (SNNP), an open unfenced area, is reported, taking into account wild boar population abundance variation in space and time in an open unfenced environment. A total of 1103 wild boar were sampled in 141 hunting events randomly carried out for sampling in seven hunting seasons (October to February from 2002-2003 to 2009-2010 (except 2007-2008). Prevalence was overall lower than those previously reported for fenced wild boar populations in Spain, but all the pathogens analyzed except PRRSV were considered endemic in the SNNP. ADV, E. rhusiopathiae and total pathogen prevalence were positively correlated to wild boar density. Prevalence in the positive areas was significantly higher in females for ADV, E. rhusiopathiae, L. pomona, Chlamydia/Chlamydiaceae sp. and Salmonella sp., and in males for M. bovis. This longitudinal study provides the first data on the health status of the relatively unmanaged and low density wild boar population of SNNP. It is concluded that non-intensively managed wild boar populations are able to maintain the circulation of several pathogens, even in low prevalences and in open unfenced areas with natural density variation both in time and space.

Reliability of an ELISA test for diagnosing oestrosis in Iberian ibex.

Oestrosis is one of the most prevalent parasitosis affecting the Iberian ibex, Capra pyrenaica . To date, both the diagnosis of oestrosis and the determination of the intensity of parasitism require the use of invasive methods (necropsy), which necessarily limit research possibilities. We analyzed the immune humoral response (IgM and IgG) against Oestrus ovis L. excretory/secretory larval antigens in 32 sera taken from Iberian ibex from the Sierra Nevada Natural Space (southern Spain). Three antigens were collected: L1OES (from L1 larvae), L2OES (L2), and L3OES (L3). Necropsy was considered as the gold standard. The percentage of ibexes harboring Oestrus spp. larvae was 88%, the mean intensity of parasitism being 16.96 ± 14.96 larvae per parasitized host (range: 2-52). In our sample, first-instar larvae (L1) were found in 9% of ibexes, while 69% of hosts carried L2 larvae and 88% L3 larvae. Positive correlations between L1 and L2 numbers, and between L2 and L3 numbers were detected. The best results with the immunoenzymatic assay were obtained using IgG antibodies against the L1OES antigens (specificity = 89%; sensitivity = 100%; positive predictive value = 100%; negative predictive value = 57%). The IgG seroprevalence against L1OES was 78%. Thus, the analysis of IgG antibodies against antigens collected from L1 O. ovis larvae would seem to be a noninvasive method for reliably diagnosing oestrosis in naturally infested Iberian ibex. Nevertheless, additional immunological and methodological advances are still required because false positive and false negative results still represent a non-negligible part of the results of the ELISA tests.

The use of radio-collars for monitoring wildlife diseases: a case study from Iberian ibex affected by Sarcoptes scabiei in Sierra Nevada, Spain.

BACKGROUND: Wildlife radio tracking has gained popularity during the recent past. Ecologists and conservationists use radio-collars for different purposes: animal movement monitoring, home range, productivity, population estimation, behaviour, habitat use, survival, and predator-prey interaction, among others. The aim of our present study is to highlight the application of radio-collars for wildlife diseases monitoring. The spread of wildlife diseases and the efficacy of management actions for controlling them propose serious challenges for ecologists and conservationists, since it is difficult to re-capture (or simply observe) the same animal in pre-determined temporal interval, but such difficulty is overcome by the use of gps-gsm radio collars. METHODS: In the present study we report, for the first time to our knowledge, the use of radio-collars in the monitoring of Iberian ibex affected by Sarcoptes scabiei in Sierra Nevada mountain range, Spain. Twenty-five moderate or slightly mangy animals were radio-collared between 2006 and 2013. RESULTS: The radio-collars allowed us to confirm the presence of resistance to S. scabiei within Iberian ibex population. Twenty (80%) of the collared animals recovered totally from mange, while the disease progressed in the other five Iberian ibex (20% of the collared animals) and the animals died. The average estimated recovery time of the resistant animals was 245 ± 277 days, and the estimated average survival time of the non-resistant Iberian ibex was 121 ± 71 days. Non-resistant animals survived at least 100 days, while all of them died with less than 200 days. Sixty per cent of the resistant animals were recovered with less than 200 days. CONCLUSIONS: We report, for the first time, the successful use of radio collars for wildlife diseases monitoring using Iberian ibex/S. scabiei as a model. By using radio collars we documented that most of the Sarcoptes-infected Iberian ibex are resistant to this disease, and we estimated the average time for Iberian ibex recovering from mange infection and the average survival time of the non-resistant ones. We expect wider use of radio-collars for wild animals diseases monitoring, affected/not-affected animals interaction, and treatment efficacy, among others.

Applicability of major histocompatibility complex DRB1 alleles as markers to detect vertebrate hybridization: a case study from Iberian ibex × domestic goat in southern Spain.

BACKGROUND: Hybridization between closely related wild and domestic species is of great concern because it can alter the evolutionary integrity of the affected populations. The high allelic variability of Major Histocompatibility Complex (MHC) loci usually excludes them from being used in studies to detect hybridization events. However, if a) the parental species don't share alleles, and b) one of the parental species possesses an exceptionally low number of alleles (to facilitate analysis), then even MHC loci have the potential to detect hybrids. RESULTS: By genotyping the exon2 of the MHC class II DRB1 locus, we were able to detect hybridization between domestic goats (Capra hircus) and free-ranging Iberian ibex (Capra pyrenaica hispanica) by molecular means. CONCLUSIONS: This is the first documentation of a Capra pyrenaica × Capra hircus hybridization, which presented us the opportunity to test the applicability of MHC loci as new, simple, cost-effective, and time-saving approach to detect hybridization between wild species and their domesticated relatives, thus adding value to MHC genes role in animal conservation and management.

Usefulness of estimated surface area of damaged skin as a proxy of mite load in the monitoring of sarcoptic mange in free-ranging populations of Iberian wild goat, Capra pyrenaica.

In this study we examined the influence of several factors, like the surface of skin with lesions attributable to Sarcoptes scabiei, the time of year and host sex and age on variations of mite load in Iberian wild goats, Capra pyrenaica, from the Sierra Nevada Natural Space, southern Spain. As well, the surface area of skin with scabietic lesions estimated during field surveys were compared with measurements taken in the laboratory and the potential for using categories based on surface areas estimated during monitoring and management programs was analyzed. The surface area of the skin lesions measured in the laboratory and the time of year were the main factors affecting mite load. Results also revealed discrepancies between the surface area of lesions estimated in the field and those measured in the laboratory. The highest error percentages were associated with lesions ranging between 25 and 75% of host skin surface area. By reducing the number of categories of mange infestation (from 5 to 3) the proportion of cases correctly classified using data from field surveys increases. Our analyses suggest that the estimated surface areas of scabietic lesions is a useful relative index of mite abundance and/or intensity of parasitation in Iberian wild goat. Therefore, we conclude that revised classifications should be used in the monitoring of sarcoptic mange in wild populations, since data can be obtained in an inexpensive, fast and non-invasive fashion.

The use of total serum proteins and triglycerides for monitoring body condition in the Iberian wild goat (Capra pyrenaica).

Body condition in wild ungulates is traditionally evaluated during the necropsy of animals on the basis of the weight of fat stored around or within the vital organs, the weight of the organs themselves, and their derived indices. However, sometimes it is important to evaluate the nutritional status of the animal by means of blood and serum analyses and the interpretation of specific parameters. Only in a very few studies is the nutritional status of the animal obtained by blood biochemistry and, when obtained, compared with the values for body condition obtained by anatomic dissection. In this study, the usefulness of two serum parameters, total serum proteins (TSP) and serum triglycerides (ST), was assessed in the monitoring of the body condition of Iberian wild goats (Capra pyrenaica). In addition, their relationship with the kidney fat index (KFI) and its components, kidney mass without fat (KM) and kidney fat (KF) is evaluated. A total of 25 wild goats from the Sierra Nevada National Park (southern Iberian Peninsula) that were shot by hunters were used in this study. The parameter TSP was found to be correlated with KM, and ST was correlated with both KM and KFI. Hence, both TSP and ST can be used for monitoring physical condition in wild and captive Iberian wild goats.

A survey of the gastrointestinal nematodes of Spanish ibex (Capra pyrenaica) in a high mountain habitat.

We analyzed the content of the abomasum (n = 79) and small intestine (n = 83) of Spanish ibex from Sierra Nevada Natural Park, southern Spain. Fifteen species of trichostrongylid nematodes were identified, 4 of which were found for the first time in this host, i.e., Nematodirus fillicollis, N. oiratianus, Ostertagia lyrata, and O. ostertagi. Teladorsagia circumcincta and Marshallagia marshalli were the most abundant abomasal species, whereas N. abnormalis, N. davtiani, and N. oiratianus were dominant in the small intestine. Counts of both abomasal and intestinal nematodes were generally low (year-round-median = 292 and 94 worms, respectively), and significantly lower numbers of M. marshalli, N. davtiani, and N. oiratianus were found in summer. No sex-related differences in helminth abundance were found, but young ibex harbored significantly more N. davtiani and N. oiratianus than adults. The presence of scabies was not related to increased nematode counts.