Bronchopulmonary nematode infection of Capra pyrenaica in the Sierra Nevada massif, Spain

Multivariate Abundance Analysis of Multi-Host/Multi-Parasite Lungworms in a Sympatric Wild Ruminant Population

In the analysis of a multi-host/multi-parasite system and its associated risk factors, it is particularly interesting to understand the natural dynamics among pathogens, their hosts, and the environment in wildlife populations. This analysis is particularly feasible in a scenario where multiple overlapping host populations are present in high densities, along with a complex community of parasites. We aimed to describe and analyze the naturally occurring lungworm polyparasitism in a wild ruminant community in Southeast Spain. The respiratory tracts of 250 specimens belonging to four different species (red deer, mouflon, Iberian ibex, and fallow deer) were studied. Almost half (48.0%) of the animals were infected with bronchopulmonary nematodes. Seven different nematodes were identified of which two genera (Protostrongylus spp. and Dictyocaulus spp.) and three additional species (Cystocaulus ocreatus, Muellerius capillaris, and Neostrongylus linearis) were recorded in at least two ruminants, with the mouflon as the commonest host. Our study shows a significant effect of host species and sampling area, plus a marginal effect of age, on parasite multivariate abundance at the host population level. Mouflon and adults of all hosts appear to carry the highest parasite load on average. From a spatial perspective, the highest parasite abundance was detected at the central part of the park.

Comparative survey of gastrointestinal parasites in sympatric Iberian ibex (Capra pyrenaica) and domestic goats using molecular host specific identification

An isolated population of several hundred Iberian ibex (Capra pyrenaica) inhabits the Gerês-Xurés Transboundary Biosphere Reserve (GXTBR) in north-western Iberian Peninsula, in partial sympatry with tens of thousands domestic goats (Capra hircus). This study aimed to assess the prevalence and shedding intensity of gastrointestinal parasites from sympatric herds of domestic goat and Iberian ibex in autumn 2018. A total of 93 pooled faecal samples were collected from GXTBR (39 from domestic goats and 54 from Iberian ibex) and the host species was identified using molecular techniques, whenever defecation was not visualised in the field. Parasitological analysis was achieved by joint Willis flotation/sedimentation, McMaster and Mini-FLOTAC techniques. Seventy-two samples (25 domestic goats and 47 Iberian ibex) were retained for analysis after discarding the least fresh and those with uncertain specific identification. Generalized linear mixed models compared prevalence and shedding intensity between caprine species. Domestic goats showed a non-significant tendency to be more parasitized than Iberian ibex, as assessed by overall prevalence (100.0%, CI₉₅ 86.7-100.0 vs. 74.5%, CI₉₅ 69.5-84.8), and shedding intensity. This study reveals a similar community of gastrointestinal parasites in an abundant livestock species and an isolated population of wild caprine, living in partial sympatry. It is the first study on the health status of this endangered Iberian ibex population, in close contact with livestock, highlighting the need for further sanitary surveillance.

Bronchopulmonary Nematodes in Alpine Ibex: Shedding of First Stage Larvae Analyzed at the Individual Host Level

Pneumonia is the most frequent cause of death for Alpine ibex (Capra ibex) in Gran Paradiso National Park, (Italy). The etiology of this form of pneumonia is currently unknown and the identification of the primary etiological agent remains difficult due to biological and logistic constraints. Uncovering individual differences in Protostrongylid prevalence and intensity is important to further investigate the epidemiology of respiratory diseases and their relationship to heterozygosity and inbreeding in a once almost extinct population like C. ibex. In a group of 21 individually recognizable adult male we monitored monthly prevalence and intensity of Protostrongylid first-stage larvae using Baerman's technique from June to September 2019. First-stage larvae of 5 genera were detected. Muellerius (P = 100%, CI_95% = 84–100) and Protostrongylus (P = 86%, CI_95%:71–100) were two dominant genera according to Bush's importance index. Neostrongylus (P = 38%,CI_95%: 17–59), Cystocaulus (P = 33%,CI_95% = 13–53) were classified as co-dominant genera while Dictyocaulus filaria (P = 0.05%, CI_95% = 0.04–0.13) was detected, for the first time in Alpine ibex, in one subject. Protostrongylidae larval excretion varied significantly over time, with minimum L1 excretion in July. Individual median larval intensity ranged from 4.4 lpg to 82.2 lpg with Poulin's discrepancy index showing highly aggregated distribution patterns for Muellerius spp. (D = 0.283, CI_95% = 0.760–0.895) and Protostrongylus spp. (D = 0.635, CI_95% = 0.580–0.705). Presented data provide the necessary base point to further investigate how lungworm infection account for the different rates of progression of pneumonia in C. ibex. Individual aggregation of larval intensity must be further evaluated to determine whether these differences mirror different levels of parasitic infection related to individual differences in immune response, hormonal-states or genetic fitness.

Evaluation of the Baermann-Wetzel method for detecting lungworm larvae in wild ruminants from faecal samples

Lungworms can exert a negative impact on wild ruminant fitness; for this reason, the diagnosis of the associated diseases is an important prevention measure. The Baerman-Wetzel technique is the most usual method for the diagnosis of bronchopulmonary nematodes and is based on the active migration and movement of their first-stage larvae. Pulmonary tissue samples are frequently used for the post-mortem diagnosis of these parasites, but this kind of sample is not always available and easy to obtain. Faecal samples represent a more accessible choice for parasite monitoring. This work aimed to evaluate the agreement between the results obtained by the Baermann-Wetzel technique when samples of lung parenchyma or faeces from wild ruminants are used. A good level of agreement as well as a similar sensitivity between the two types of sample were observed, validating the use of faecal samples as a less invasive and cost-effective alternative for the monitoring of lungworm in wild ruminant populations.

Lungworms and gastrointestinal parasites of domestic cats: a European perspective

With the exception of Aelurostrongylus abstrusus, feline lungworms have been poorly studied. Information on their distribution is patchy and mostly limited to case reports. In this study, the occurrence of feline lungworms and co-infecting gastrointestinal parasites has been investigated in 12 European countries (i.e. Austria, Belgium, Bulgaria, France, Greece, Hungary, Italy, Portugal, Romania, Spain, Switzerland and the United Kingdom). An average of 10 domestic cats, with regular outdoor access, was sampled each month for 12months, and freshly passed faeces were collected. Stools were processed using a McMaster assay and a quantitative Baermann-Wetzel method. Animals positive for lungworms and/or gastrointestinal parasites were treated with a formulation containing fipronil, (S)-methoprene, eprinomectin, and praziquantel (Broadline®, Merial), and re-sampled 28days post-treatment. The association between lungworm infection and risk factors was analysed using statistical medians/means and the efficacy of the treatment against each lungworm species was assessed. Of 1990 cats sampled, 613 (30.8%) were positive for at least one parasite, while 210 (10.6%) were infected by lungworms. The prevalence of lungworm infection varied between the sampled sites, with the highest recorded in Bulgaria (35.8%) and the lowest in Switzerland (0.8%). None of the cats from Austria or the United Kingdom were infected by lungworms. Aelurostrongylus abstrusus was the species most frequently detected (78.1%), followed by Troglostrongylus brevior (19.5%), Eucoleus aerophilus (14.8%) and Oslerus rostratus (3.8%). The overall efficacy of the treatment was 99% for A. abstrusus and 100% for T. brevior, O. rostratus and E. aerophilus. Data presented provide a comprehensive account of the diagnosis, epidemiology and treatment of feline lungworms in Europe, as well as of the occurrence of co-infections by gastrointestinal parasites.

Cephenemyiosis, an emergent myiasis in roe deer (Capreolus capreolus) from northwestern Spain

Cephenemyia stimulator larvae cause a specific myiasis in roe deer, which is widely distributed in Europe. In Spain, this parasite was detected by the first time in 2005, coinciding with a high mortality of this ruminant especially in northwest of the country. The aim of this study was to analyse the results obtained by necropsy and ELISA to elucidate when the first infestation by C. stimulator in roe deer from northwestern Spain occurred, as well as to determine the influence of some intrinsic factors on the prevalence and intensity of infestation. During 1994-2000, none seropositive roe deer was observed by ELISA. However, from 2007 to 2014, 38 % of animals were seropositive. The results of the necropsy pointed that prevalence and intensity of infestation had increased over the years. There was a positive and significant correlation between the number of animals harbouring C. stimulator larvae and seroprevalence values. This significant correlation was also observed between the seroprevalence and mean intensity of infestation. Adult roe deer showed higher prevalence and intensity of infestation than younger reaching statistical significance. It is also detected that the prevalence of infestation was significantly higher in males than in females although the mean number of larvae found in females were higher than in males. The combined use of direct and indirect techniques demonstrated a high prevalence of C. stimulator infestation in roe deer in the northwest of Spain, which certainly highlights the importance of this myiasis during the last years.

Lungworms in Alpine ibex (Capra ibex) in the eastern Alps, Italy: An ecological approach

Host-parasite relationships have been frequently investigated in mountain dwelling ungulates, though mostly focusing on gastrointestinal nematodes. On the contrary, very few studies were conducted on broncopulmonary nematodes, which may result in severe parenchymal lesions and act as predisposing factor for multifactorial pneumonia. The epidemiological and ecological features of lungworms infecting an Alpine ibex population in the Eastern Alps, Italy, were non-invasively investigated by means of a modified Baermann technique with an original quantitative methodology. Out of a total of 269 samples collected monthly from July to November 2013 and from July to October 2014, 212 (78.8%) were positive for Muellerius and 26 (9.7%) for Protostrongylus, whereas Neostrongylus and Cystocaulus were less prevalent (4.1% and 0.7%, respectively). None of the investigated samples tested positive for dictyocaulids. The genus Muellerius showed the highest larval output intensity (134.2 L1/g), followed by Protostrongylus with 33.8 L1/g. A contrasting age-related pattern of Muellerius and Protostrongylus was revealed, with the former significantly more prevalent and abundant in adult animals, while the latter in kids. Due to the limited accessibility of the study area during winter and spring, it was difficult to describe clear seasonal trends in larval output, although Muellerius showed a minimum in the late summer and a rise in the autumn. The newly developed diagnostic method showed a fair repeatability, thus representing an interesting tool to investigate the ecology of lungworms in protected species, such as the A. ibex. Based on results, ibex in the Marmolada massif seem to have an ecologically stable relationship with their lungworm community.