Nemabiome metabarcoding shows a high prevalence of Haemonchus contortus and predominance of Camelostrongylus mentulatus in alpaca herds in the northern UK.

Gastrointestinal nematodes (GINs) are a common threat faced by pastoral livestock. Since their major introduction to the UK in the early 1990s, South American camelids have been cograzed with sheep, horses, and other livestock, allowing exposure to a range of GIN species. However, there have been no molecular-based studies to investigate the GIN populations present in these camelids. In the current study, we sampled nine alpaca herds from northern England and southern Scotland and used high-throughput metabarcoded sequencing to describe their GIN species composition. A total of 71 amplicon sequence variants (ASVs) were identified representing eight known GIN species. Haemonchus contortus was the most prevalent species found in almost all herds in significant proportions. The identification of H. contortus in other livestock species is unusual in the northern UK, implying that alpacas may be suitable hosts and potential reservoirs for infection in other hosts. In addition, the camelid-adapted GIN species Camelostrongylus mentulatus was identified predominantly in herds with higher faecal egg counts. These findings highlight the value of applying advanced molecular methods, such as nemabiome metabarcoding to describe the dynamics of gastrointestinal nematode infections in novel situations. The results provide a strong base for further studies involving cograzing animals to confirm the potential role of alpacas in transmitting GIN species between hosts.

The occurrence of Sarcocystis spp. in the myocardium of alpacas (Vicugna pacos) with associated risk factors in the Peruvian Andes.

Sarcocystis masoni n. sp. (known as "S. lamacanis") infects alpacas affecting their productivity and can cause a food poisoning syndrome in humans by consuming contaminated, undercooked cardiac muscle. There are few studies estimating the prevalence of this parasite in alpacas, although this information is crucial for the control and prevention of sarcocystosis. This study aimed to determine the frequency and density of Sarcocystis masoni n. sp. in the heart of alpacas in Huancavelica, a province of the Andean region of Peru. Heart samples were taken for histopathology from 104 alpacas slaughtered at the municipal slaughterhouse of Huancavelica, the official abattoir in the Huancavelica district. No macroscopic sarcocysts were observed. All alpacas (100%) had microscopic sarcocysts of Sarcocystis masoni n. sp., with no inflammatory reactions. The alpacas showed an average sarcocyst density of 60.8 ± 23.3/mm2. Sarcocysts density was significantly higher (p < 0.05) as the age of the animals increased. In addition, sarcocysts density was significantly higher (p < 0.05) in male animals aged 4 and 5 years compared to females of the same age. These results confirmed that heart sarcocystosis is highly endemic in Peruvian alpacas. Therefore, it is recommended that alpaca hearts be well-cooked at the time of consumption. The present study showed current data and contributes to the knowledge of this parasitosis. Studies of this nature are necessary because they are the basis for developing animal health programs.

First report about a cerebrospinal nematode infection in an alpaca (Vicugna pacos).

The number of New World camelids in European farms is rising and thus, the need for veterinary care towards these animals arises. However, veterinary care requires sophisticated knowledge on disease and pathogen occurrence within New World camelids. Here, an alpaca cria with neurological signs was admitted to the veterinary clinic. Although the animal was treated with antibiotics, vitamins and dexamethason, it refused to drink milk and the clinical status worsened. After euthanasia, necropsy and histopathological examination were carried out and revealed intracerebral nematode larvae. The morphology of these larvae strongly suggests them to be Baylisascaris procyonis, a parasite of raccoons. The extended history revealed that a fully grown raccoon was living within farm enclosures, suggesting an infection of the alpaca and the development of a cerebrospinal larva migrans. This zoonotic disease is characterized by aberrant larval migration that typically shows extraintestinal migration in dead-end hosts. The aim of this report is to sensitize practical colleagues towards this rare, but occasionally fatal infection in New World camelids while familiarizing diagnostic pathologists with the morphological characteristics of this disease.

Postmortem diagnoses in South American camelids and factors influencing diagnostic rate in the Upper Midwest USA, 2009-2019.

South American camelids (SACs) have become increasingly popular as livestock and companion animals in the Midwestern United States. With increased ownership, postmortem evaluations and samples available for diagnostic assessment are being submitted more frequently to veterinary diagnostic laboratories. We searched archived pathology records at the Wisconsin Veterinary Diagnostic Laboratory (WVDL) between 2009-2019 for SAC cases. Postmortem records from 166 alpacas and 27 llamas were included, with an average of 1.42 diagnoses per animal. The overall average diagnostic rate was 79.8%. Abortion and neonatal cases (fetus to 1-wk-old) had the lowest diagnostic rate (33.3%) and was the only group with a diagnostic rate statistically significantly lower than the average. The most common diagnoses were gastrointestinal parasitism and suboptimal nutritional status or inanition; 78% of cases diagnosed with suboptimal nutritional status were also parasitized. The gastrointestinal parasites identified most frequently were Eimeria sp. and strongyles, especially Nematodirus sp. Our findings may aid allocation of diagnostic resources to better serve regional SAC populations and provide a framework for practitioners who send samples to laboratories for analysis. Submission of whole bodies, euthanized animals, fresh tissue, and inclusion of placental tissues in abortion cases are recommended for optimal diagnostic outcome.

First report of Eimeria and Entamoeba infection in alpacas (Vicugna pacos) in Shanxi Province, northern China.

Intestinal protozoa Eimeria and Entamoeba can infect many animal species including alpacas. However, data on the prevalence and pathogenicity of species of the two genera Eimeria and Entamoeba in alpacas in China is scarce. The current study was carried out to investigate the prevalence of Eimeria and Entamoeba in alpacas in two cities (Taiyuan and Xinzhou) in Shanxi Province, northern China, using PCR-based approaches. Eimeria spp. were only found in Taiyuan city, and the overall prevalence was 1.64%. All samples collected from male alpacas were PCR-negative for Eimeria. Four Eimeria-positive samples were tested positive as Eimeria lamae. The molecular prevalence of Entamoeba in alpacas was 18.03% (66/366), including 16.39% (50/305) in alpacas from Taiyuan city and 26.23% (16/61) from Xinzhou city, respectively. The Entamoeba prevalence in male alpacas (25.00%) was significantly higher than that in female alpacas (15.69%). Entamoeba bovis was the predominant species, and no Entamoeba histolytica infection was detected. Nine unique SSU rRNA gene sequences of Entamoeba were obtained which formed a new cluster. The results showed that sex and location might be the risk factors associated with prevalence of Eimeria spp., and sex might be the risk factor associated with prevalence of Entamoeba spp.. This is the first report of Entamoeba in alpacas worldwide. These findings expand our understanding of the prevalence and genetic diversity of Eimeria and Entamoeba in alpacas.

Treatment of sarcoptic and chorioptic mange in an alpaca (Vicugna pacos) herd with a combination of topical amitraz and subcutaneous ivermectin.

Clinical history: An outbreak of intense pruritus and weight loss in a herd of 40 alpacas (Vicugna pacos) in the south-west of France was investigated after the death of 14 adults. One alpaca was referred to a veterinary teaching hospital for diagnosis and treatment but died soon after and one of the dead alpacas was submitted for necropsy. Clinical findings: The remaining alpacas were intensely pruritic with variably severe and extensive alopecia, erythema, lichenification and crusting on the face, ventral abdomen and distal limbs. Superficial skin scrapes from five animals revealed large numbers of Sarcoptes scabiei mites, and less frequent and numerous Chorioptes bovis mites. Coproscopic examinations revealed a median of 1,350 (min 500, max 8800) strongyle epg. The alpaca admitted for treatment was anaemic and hypoalbuminaemic. Skin scrapes revealed copious S. scabiei and C. bovis mites. The two alpacas examined post-mortem had similar skin lesions to those examined on-farm and were cachexic. One had lung lesions attributed to protostrongylid infestation and its liver contained numerous Dicrocoelium spp. adults. Diagnosis: Sarcoptic and chorioptic mange with secondary superficial bacterial skin infection, associated with severe internal parasitism and underfeeding. Treatment and outcome: All 25 alpacas were treated topically with a 3% chlorhexidine shampoo followed by a 0.025% amitraz wash at the initial visit and then 1, 2, 3, 7 and 9 weeks later. A systemic treatment with S/C 500 µg/kg ivermectin was administered at the initial visit and then 2, 7 and 9 weeks later. The alpacas were treated orally with 50 mg/kg praziquantel to control dicrocoeliosis. Nutritional measures, including increased pasture area and supplemental feeding were simultaneously implemented. Pruritus was reduced 1 week after the start of treatment and had resolved after 2 weeks. After 9 weeks, skin lesions were markedly improved. Six months after the initial visit, skin lesions entirely resolved and superficial skin scrapes, taken from half of the animals, were negative for mites. Clinical relevance: This is the first report of the use of two acaricides combined with a chlorhexidine shampoo to successfully treat simultaneous sarcoptic and chorioptic mange in alpacas.

Prevalence and Subtypes of Blastocystis in Alpacas, Vicugna pacos in Shanxi Province, China.

Blastocystis, an enteric protist, has been reported to be an important cause of protozoal gastrointestinal manifestations in humans and animals worldwide. Animals harboring certain Blastocystis subtypes (STs) may serve as a potential source of human infection. However, information about the prevalence and genetic diversity of Blastocystis in alpacas is limited. In the present study, a total of 366 fecal samples from alpacas in Shanxi Province, northern China, were examined for Blastocystis by PCR amplification of the small subunit rRNA gene, followed by sequencing and phylogenetic analysis. The prevalence of Blastocystis in alpacas was 23.8%, and gender difference in the prevalence of Blastocystiswas observed. The most predominant Blastocystis ST was ST10, followed by ST14 and ST5. The detection of ST5, a potentially zoonotic genotype, indicates that alpacas harboring ST5 could be a potential source of human infection with Blastocystis. These data provide new insight into the prevalence and genetic diversity of Blastocystis in alpacas.

Toxoplasma gondii and Neospora caninum infections in South American camelids in Switzerland and assessment of serological tests for diagnosis.

BACKGROUND: Little is known about the epidemiology of Toxoplasma gondii and Neospora caninum infections in alpacas (Vicugna pacos) and llamas (Lama glama) outside South America. The study aimed to estimate the seroprevalence of T. gondii and N. caninum infections in South American camelids (SAC) in Switzerland, to optimize serological tests for SAC and to identify risk factors, which may favour infection. METHODS: A total of 571 sera from 132 Swiss farms (374 alpacas and 197 llamas, mean 4.3 animals/farm) were obtained. Four commercial enzyme-linked immunosorbent assays (ELISA) for detecting antibodies against T. gondii (ID Screen® Toxoplasmosis Indirect (TOXO-MS)) or N. caninum (i.e. ID Screen® Neospora caninum Indirect Multi-species (NCS-MS); ID Screen® Neospora caninum Competition (NCC) and ID Screen® Neospora caninum Indirect (NCS)) were first assessed for their use on SAC comparing their results with those in immunoblot, and optimizing cut-offs. Subsequently, two kits (TOXO-MS and NCS-MS) were selected for seroprevalence estimation. Additionally, a risk factor analysis for infection was performed on 41 farms, which agreed to participate in a web-based survey. RESULTS: Three kits (TOXO-MS, NCS-MS and NCC) showed almost perfect agreement (kappa > 0.901) with immunoblot results when the cut-offs were optimized, and one kit (NCS) proved not to be useful for detecting N. caninum seropositive SAC. By TOXO-MS ELISA, 82.3% (308/374) of the alpacas and 84.8% (167/197) of the llamas were seropositive for T. gondii, and 131/132 (99.2%) farms had seropositive animals. By NCS-MS ELISA, 3.5% (13/374) of the alpacas and 2.5% (5/197) of the llamas evidenced antibodies against N. caninum, and 9.1% (12/132) of the farms had seropositive animals. The variables "age" and "female sex" were identified as risk factors for T. gondii infection and "absence of cats in the farm during the last two years" as a protective factor. No risk or protective factors for N. caninum infection could be identified. CONCLUSIONS: This nationwide cross-sectional study demonstrated for the first time the presence of antibodies against T. gondii and N. caninum in the Swiss SAC population, highlighting a high seroprevalence for T. gondii, the presence of cats as a risk factor and suggesting that SAC meat might represent an additional infection source for humans.

Cryptosporidium parvum as a risk factor of diarrhea occurrence in neonatal alpacas in Peru.

Cryptosporidiosis has been reported as an important cause of neonatal diarrhea and mortality in cattle, sheep, and other ruminants, but its impact on alpaca health has not been studied thoroughly. In this study, we have determined the prevalence and evaluated the role of cryptosporidiosis as a risk factor for diarrhea occurrence in newborn alpacas. During the calving season (January-March) of 2006, stool specimens (N = 1312) were collected from 24 herds of newborn alpacas in Puno and Cuzco, departments that account for the largest populations of alpacas in Peru. All the specimens were microscopically screened for Cryptosporidium spp. using the acid-fast technique. The association between Cryptosporidium detection and diarrhea was analyzed using χ2 test and generalized lineal model. Cryptosporidium species were determined by PCR-RFLP analysis of the small subunit rRNA gene. Cryptosporidium oocysts were detected in 159 of 1312 (12.4%) newborn alpacas. Results of the analyses demonstrated that crypstosporidiosis was significantly associated with diarrhea (PR = 3.84; CI95% 2.54-5.81; p < 0.0001). Only Cryptosporidium parvum was detected in the 153 Cryptosporidium-infected animals. Thus, there is an association of C. parvum infection with diarrhea in neonatal alpacas.

In silico identification of immunotherapeutic and diagnostic targets in the glycosylphosphatidylinositol metabolism of the coccidian Sarcocystis aucheniae.

Meat of the South American camelids (SACs) llama and alpaca is an important source of animal protein and income for rural families in the Andes, and a product with significant growth potential for local and international markets. However, infestation with macroscopic cysts of the coccidian protozoon Sarcocystis aucheniae, a parasitosis known as SAC sarcocystosis, significantly hampers its commercialization. There are no validated methods to diagnose the presence of S. aucheniae cysts other than carcass examination. Moreover, there are no available drugs or vaccines to cure or prevent SAC sarcocystosis. Identification of relevant molecules that act at the host-pathogen interface can significantly contribute to the control of this disease. It has been shown for other pathogenic protozoa that glycosylphosphatidylinositol (GPI) is a critical molecule implicated in parasite survival and pathogenicity. This study focused on the identification of the enzymes that participate in the S. aucheniae GPI biosynthetic pathway and the repertoire of the parasite GPI-anchored proteins (GPI-APs). To this aim, RNA was extracted from parasite cysts and the transcriptome was sequenced and translated into amino acid sequences. The generated database was mined using sequences of well-characterized GPI biosynthetic enzymes of Saccharomyces cerevisiae and Toxoplasma gondii. Eleven enzymes predicted to participate in the S. aucheniae GPI biosynthetic pathway were identified. On the other hand, the database was searched for proteins carrying an N-terminal signal peptide and a single C-terminal transmembrane region containing a GPI anchor signal. Twenty-four GPI-anchored peptides were identified, of which nine are likely S. aucheniae-specific, and 15 are homologous to membrane proteins of other coccidians. Among the latter, 13 belong to the SRS domain superfamily, an extensive group of coccidian GPI-anchored proteins that mediate parasite interaction with their host. Phylogenetic analysis showed a great degree of intra- and inter-specific divergence among SRS family proteins. In vitro and in vivo experiments are needed to validate S. aucheniae GPI biosynthetic enzymes and GPI-APs as drug targets and/or as vaccine or diagnostic antigens.

Prevalence and multilocus genotypes of Enterocytozoon bieneusi in alpacas (Vicugna pacos) in Shanxi Province, northern China.

Enterocytozoon bieneusi is a single-celled obligate pathogen that seriously threatens animal and public health. However, information on the prevalence and genotypes of E. bieneusi in alpacas in China is limited. In the present study, 366 fresh fecal samples from alpacas in Shanxi Province, northern China, were collected to detect E. bieneusi by nested PCR amplification of the internal transcribed spacer (ITS) of nuclear ribosomal DNA (rDNA). The overall prevalence of E. bieneusi in alpacas was 4.4% (16/366), including 3.9% (12/305) in Yangqu County and 6.6% (4/61) in Dai county, respectively. Four known genotypes were identified, namely ALP1, ALP3, P, and SH11, all of which belong to the zoonotic group 1 by phylogenetic analysis. Moreover, ITS-positive samples were further characterized by PCR amplification of other four targets, including three microsatellites (MS1, MS3, and MS7) and one minisatellite (MS4). Multilocus sequence typing (MLST) showed that 5, 2, 3, and 3 types were identified at MS1, MS3, MS7, and MS4 loci, respectively, representing eight multilocus genotypes (MLGs). These findings contribute to the improved understanding of the prevalence and genotypes of E. bieneusi in alpacas in China and have important implications for controlling E. bieneusi infections in animals and humans.

Mycoplasma haemolamae and intestinal parasite relationships with erythrocyte variables in clinically healthy alpacas and llamas.

BACKGROUND: Mycoplasma haemolamae (Mhl) and gastrointestinal nematodes can cause anemia in camelids. Control programs aim to suppress parasitism without promoting anthelminthic resistance, but few evidence-based guidelines define acceptable parasite loads in camelids. HYPOTHESIS/OBJECTIVES: In clinically healthy nonanemic camelids, compare erythrocyte variables to Mhl real-time PCR status and to fecal egg count (FEC). Determine the FEC threshold above which erythrocyte variables are consistently below reference interval medians. ANIMALS: One hundred fourteen client-owned adult alpacas and llamas. METHODS: In a cross-sectional study, whole blood in ethylenediaminetetraacetic acid (EDTA) was assessed for packed cell volume (PCV) by centrifugation, erythrocyte count (RBC), and hemoglobin concentration (HGB) using an ADVIA120 analyzer, and Mhl using real-time PCR. Trichostrongyle eggs per gram (epg) were counted by modified McMaster test on freshly collected feces. Significant differences in erythrocyte variables based on Mhl status and FEC thresholds were assessed by independent t test and one-way ANOVA, respectively. RESULTS: Packed cell volume, RBC, and HGB were not significantly different between Mhl-positive and Mhl-negative animals, but were significantly lower in animals with FEC >1000 epg compared to those with <500 epg. All animals with FEC >600 epg had RBC and HGB below the reference interval median. All animals with FEC >750 epg had PCV below the reference interval median. CONCLUSIONS AND CLINICAL IMPORTANCE: In healthy nonanemic camelids, positive Mhl PCR is not associated with lower erythrocyte variables and such animals may not warrant treatment. Fecal egg count >600-750 epg has a negative effect on erythrocyte variables, and may be a guide for deworming protocols.

Alopecia a potential adverse side effect of albendazole use in alpacas.

Albendazole is a benzimidazole derivative with anthelmintic activity. It is the treatment of choice for fasciolosis. The use of albendazole in South American camelids is common, however, there are no studies about the pharmacokinetics and pharmacodynamics of albendazole in alpacas and llamas. In the present study, a case of fiber loss (alopecia) in alpacas is described because of the suspected use of a high dose of albendazole. In a fasciolosis control program of an alpaca ranch located in the district of Nuñoa in Puno, Peru, 2184 alpacas were oral treated with albendazole (35-40 mg/kg). After 2 weeks of treatment the alpacas began to show loss of fiber in the abdomen, flanks and neck. The alpacas showed no other sign of disease. The alpacas recovered their fiber after 6 months. We suggest studies are needed to determine the safe dose of albendazole in alpacas.

Current anthelmintic treatment is not always effective at controlling strongylid infections in German alpaca herds.

BACKGROUND: Endoparasites are considered a major health problem of South American camelids as shown in a recent survey among German and Austrian camelid owners. Although prophylactic and therapeutic measures such as application of anthelmintics are commonly used, treatment efficacy is usually not assessed. Owners have expressed significant concerns regarding the effect of antiparasitic therapy, so this study aimed to evaluate the outcome of anthelmintic treatment in German alpaca herds with different drugs. RESULTS: Overall, 617 samples from 538 clinically healthy alpacas > 1 year-old from 27 farms (n = 11-157 animals/herd) were examined. The most common parasites detected by flotation were Eimeria spp. (75.1%) followed by strongylids (55.0%), Nematodirus spp. (19.3%), cestodes (3.1%) and Trichuris (2.7%). After initial coproscopical examination by flotation and strongylid egg quantification by the McMaster technique, positive animals excreting at least 150 eggs per gram of faeces were included in a faecal egg count reduction test (FECRT) using fenbendazole (n = 71 samples), moxidectin (n = 71) or monepantel (n = 66). Pre-treatment larval cultures (n = 23 positive pooled farm samples) revealed Haemonchus (87% of the farms), Cooperia (43.5%), Trichostrongylus (21.7%), Ostertagia (13.0%), Nematodirus and Oesophagostomum (4.3% each). Fenbendazole treatment reduced egg excretion by 45%, moxidectin by 91% and monepantel by 96%. On the farm level, 13/18 farms that used fenbendazole, 6/6 farms that used moxidectin and 2/5 farms that used monepantel had individual FECR values < 90% (fenbendazole) or < 95% (moxidectin, monepantel). Haemonchus and Cooperia were overrepresented on the farms with reduced treatment efficacy. CONCLUSIONS: Gastrointestinal strongylids are common in German alpacas and fenbendazole in particular was not sufficiently effective to reduce strongylid egg excretion. Although the FECRT could not unambiguously determine anthelmintic resistance in the present study, the finding that small ruminant strongylids, especially Haemonchus, are common in alpacas indicates that determination of effective anthelmintic doses, monitoring of efficacy and adapted (selective) treatment regimens must be implemented as part of sustainable deworming practices in this species in accordance with recommendations for ruminants.

First report of a Hypoderma diana infestation in alpaca (Vicugna pacos) in Germany.

A Hypoderma larva was removed from a painful swelling in the lumbar region of a 17-month-old male alpaca kept on a farm in the Brandenburg district, eastern Germany. Morphological analysis and sequencing of the 18S rRNA gene demonstrated it was a second instar larvae of Hypoderma diana. The main host of H. diana is the roe deer (Capreolus capreolus). This is the first description of hypodermosis caused by H. diana in a camelid species.

Epidemiology of gastrointestinal nematodes of alpacas in Australia: I. A cross-sectional study.

This study involved a national cross-sectional survey of gastrointestinal nematodes (GINs) of alpacas in Australia. A total of 1545 fresh faecal samples were collected from both sexes of alpacas and processed for faecal egg counts (FEC) and molecular identification of nematodes using the multiplexed tandem PCR assay. Based on egg morphology, the overall prevalence of GINs was 66% while that for strongyles was 59%. The overall mean FEC was 276 eggs per gram (EPG) of faeces, with the highest count of 17,415 EPG. Male alpacas had a higher prevalence (68%, 334/490) as well as mean FEC (328 ± 60 EPG) of GINs than females (63%, 602/954; 227 ± 26, respectively). Weaners had the highest prevalence (80%) whereas tuis had the highest FEC (402 EPG) of nematodes. The highest prevalence (77%, 293/383) and FEC (630 EPG) of GINs were observed in the summer rainfall zone followed by the Mediterranean-type rainfall, non-seasonal rainfall and winter rainfall zones. The characterisation of nematode DNA isolated from faeces revealed the occurrence of seven different GINs, including Camelostrongylus mentulatus, Cooperia spp., Haemonchus spp., Oesophagostomum spp., Ostertagia ostertagi, Teladorsagia circumcincta and Trichostrongylus spp. Besides, Nematodirus spp. and Trichuris spp. were also found during FECs. The prevalence of Haemonchus spp. was highest in the summer rainfall zone while that of C. mentulatus was highest in the Mediterranean-type rainfall, non-seasonal rainfall and winter rainfall zones. The findings of this study revealed that alpacas harbour many of the same nematodes as sheep and cattle.

Epidemiology of gastrointestinal nematodes of alpacas in Australia: II. A longitudinal study.

We conducted a longitudinal survey on 13 alpaca farms in four climatic zones of Australia to understand the epidemiology of gastrointestinal nematodes (GINs) of alpacas. A total of 1688 fresh faecal samples were collected from both sexes of alpacas from May 2015 to April 2016 and processed for faecal egg counts (FEC) and molecular identification of eggs using the multiplexed-tandem PCR assay. Based on egg morphology, the overall prevalence of GINs was 61% while that for strongyles was 53%. The overall mean FEC was 168 eggs per gram (EPG) of faeces, with the highest count of 15,540 EPG. Weaners had the highest prevalence (73%) and mean FEC (295 EPG) of GINs followed by tuis, crias and adults. Alpacas in the winter rainfall zone had the highest prevalence (68%) as well as FEC (266 EPG) followed by Mediterranean-type, non-seasonal and summer rainfall zones. Trichostrongylus spp. (83%, 89/107), Haemonchus spp. (71%, 76/107) and Camelostrongylus mentulatus (63%, 67/107) were the three most common GINs of alpacas across all climatic zones. The mixed-effects zero-inflated negative binomial regression model used in this study showed that it could help to design parasite control interventions targeted at both the herd level and the individual alpaca level. The findings of this study showed that the epidemiology of GINs of alpacas is very similar to those of cattle and sheep, and careful attention should be paid when designing control strategies for domestic ruminants co-grazing with alpacas.

Worm burdens and associated histopathological changes caused by gastrointestinal nematodes in alpacas from Australia.

In this study, 100 gastrointestinal tracts of Australian alpacas were examined to assess the worm burden and to identify the species of nematode present. Faecal samples were collected from 97 alpacas and processed for faecal egg counts (FECs). For identification of the species, both molecular (multiplexed-tandem polymerase chain reaction [MT-PCR]) and morphological techniques were used. Total worm counts (TWCs) revealed a mean burden of 1300 worms, with the highest burden of 29,000 worms. The average egg count was 501 eggs per gram of faeces (EPG), with the highest count of 3500 EPG. Nineteen different species of gastrointestinal nematodes (GINs) were identified, and Graphinema auchenia, Camelostrongylus mentulatus and Trichuris tenuis were recovered from Australian alpacas for the first time. Haemonchus contortus was the most prevalent nematode (81%) followed by C. mentulatus (60%). The majority of the nematodes found are shared with sheep, goats and cattle. Findings of this study provide useful insights into the spectrum of GINs and their burden in Australian alpacas.

First mitochondrial and nuclear DNA sequences of Lamanema chavezi (Nematoda: Molineidae): Novel findings to improve its identification in feces from South American camelids.

Lamanema chavezi (Family Molineidae) is a parasitic nematode of South American camelids (SACs). A few studies have reported this parasite in SACs, mainly in domestic camelid species (llama and alpaca). Parasite identification by means of copro-parasitological methods is non-invasive and allows performing epidemiological studies. However, egg misidentification and difficulty to culture third-stage larvae do not allow identifying nematodes to species level. In contrast, molecular tools allow identifying eggs of gastrointestinal nematodes more accurately. However, the little genomic information available in databases for some species prevents an accurate diagnosis. In the present work, L. chavezi females present in feces of llamas from northwestern Argentina were molecularly characterized to obtain genomic information and improve parasitological diagnosis of L. chavezi-like eggs present in guanaco feces from southeastern Argentina. An 833-bp fragment of nuclear ribosomal DNA (rDNA) and a 434-bp fragment of the mitochondrial cytochrome c oxidase subunit 1 (cox1) gene from both L. chavezi females and eggs were amplified and sequenced. Comparison between sequences from females and eggs showed 99-99.6% identity to rDNA and 99.5-96.1% to the cox1 gene fragments, confirming egg morphological assignment. A higher divergence between sequences was observed in the cox1 fragment, with a maximum variation of 3.9%. The examination of eggs found in guanaco feces from southeastern Argentina and their specific molecular identification represent the first record for this host in Argentine Patagonia and contribute to improving the diagnosis of gastrointestinal nematodes in SACs, mainly in wild camelids.

First report on nasal myiasis in an alpaca "Vicugna pacos" - a case report.

BACKGROUND: An infestation of bot fly larvae causes myiasis which is known to cause respiratory symptoms in ruminants. There are reports of bot fly larvae in llamas, but to our knowledge there are no previous reports of nasal myiasis due to bot flies in alpacas ("Vicugna pacos"). CASE PRESENTATION: The following case report describes a neutered male alpaca showing sneezing and mild nasal discharge. Endoscopic examination of the upper respiratory tract revealed bot fly larvae in one nostril. After treatment with doramectin, there was no evidence of living bot fly larvae visible in the nostril. CONCLUSION: Bot fly larvae should be considered as a potential cause of respiratory symptoms in alpacas. In the present case, a treatment with doramectin was successful.