AlpaPICO: Extraction of PICO frames from clinical trial documents using LLMs

In recent years, there has been a surge in the publication of clinical trial reports, making it challenging to conduct systematic reviews. Automatically extracting Population, Intervention, Comparator, and Outcome (PICO) from clinical trial studies can alleviate the traditionally time-consuming process of manually scrutinizing systematic reviews. Existing approaches of PICO frame extraction involves supervised approach that relies on the existence of manually annotated data points in the form of BIO label tagging. Recent approaches, such as In-Context Learning (ICL), which has been shown to be effective for a number of downstream NLP tasks, require the use of labeled examples. In this work, we adopt ICL strategy by employing the pretrained knowledge of Large Language Models (LLMs), gathered during the pretraining phase of an LLM, to automatically extract the PICO-related terminologies from clinical trial documents in unsupervised set up to bypass the availability of large number of annotated data instances. Additionally, to showcase the highest effectiveness of LLM in oracle scenario where large number of annotated samples are available, we adopt the instruction tuning strategy by employing Low Rank Adaptation (LORA) to conduct the training of gigantic model in low resource environment for the PICO frame extraction task. More specifically, both of the proposed frameworks utilize AlpaCare as base LLM which employs both few-shot in-context learning and instruction tuning techniques to extract PICO-related terms from the clinical trial reports. We applied these approaches to the widely used coarse-grained datasets such as EBM-NLP, EBM-COMET and fine-grained datasets such as EBM-NLPrev and EBM-NLPh. Our empirical results show that our proposed ICL-based framework produces comparable results on all the version of EBM-NLP datasets and the proposed instruction tuned version of our framework produces state-of-the-art results on all the different EBM-NLP datasets. Our project is available at https://github.com/shrimonmuke0202/AlpaPICO.git.

Evaluating the Potential of AI Chatbots in Treatment Decision-making for Acquired Bilateral Vocal Fold Paralysis in Adults

OBJECTIVES

The development of artificial intelligence-powered language models, such as Chatbot Generative Pre-trained Transformer (ChatGPT) or Large Language Model Meta AI (Llama), is emerging in medicine. Patients and practitioners have full access to chatbots that may provide medical information. The aim of this study was to explore the performance and accuracy of ChatGPT and Llama in treatment decision-making for bilateral vocal fold paralysis (BVFP).

METHODS

Data of 20 clinical cases, treated between 2018 and 2023, were retrospectively collected from four tertiary laryngology centers in Europe. The cases were defined as the most common or most challenging scenarios regarding BVFP treatment. The treatment proposals were discussed in their local multidisciplinary teams (MDT). Each case was presented to ChatGPT-4.0 and Llama Chat-2.0, and potential treatment strategies were requested. The Artificial Intelligence Performance Instrument (AIPI) treatment subscore was used to compare both Chatbots' performances to MDT treatment proposal.

RESULTS

Most common etiology of BVFP was thyroid surgery. A form of partial arytenoidectomy with or without posterior transverse cordotomy was the MDT proposal for most cases. The accuracy of both Chatbots was very low regarding their treatment proposals, with a maximum AIPI treatment score in 5% of the cases. In most cases even harmful assertions were made, including the suggestion of vocal fold medialisation to treat patients with stridor and dyspnea. ChatGPT-4.0 performed significantly better in suggesting the correct treatment as part of the treatment proposal (50%) compared to Llama Chat-2.0 (15%).

CONCLUSION

ChatGPT and Llama are judged as inaccurate in proposing correct treatment for BVFP. ChatGPT significantly outperformed Llama. Treatment decision-making for a complex condition such as BVFP is clearly beyond the Chatbot's knowledge expertise. This study highlights the complexity and heterogeneity of BVFP treatment, and the need for further guidelines dedicated to the management of BVFP.

Anaemia in South American camelids - an overview of clinical and laboratory diagnostics

South American camelids (SACs) play an increasing role in veterinary care in Europe. Many alpacas or llamas presented to veterinarians suffer from anaemia, regularly with a packed cell volume (PCV) below 0.10 l/l, which is a life-threatening condition for the animals. This review article presents clinical and laboratory diagnostic tools for the diagnosis of anaemia in SACs. Clinical identification of anaemic animals can be performed by assessing the FAMACHA© score and the Body Condition Score (BCS), since anaemia in alpacas and llamas correlates with pale mucous membranes and a lowered BCS. Haematological examination of a blood sample can provide a more differentiated diagnosis of anaemia in SACs. A common finding is regenerative anaemia with an increased number of reticulocytes that is often caused by blood loss due to Haemonchus contortus. Changes in a blood smear from an alpaca or llama with regenerative anaemia may include normoblasts (nucleated red blood cells), anisocytosis, poikilocytosis, polychromasia, Howell-Jolly bodies or basophilic stippling. Furthermore, non-regenerative anaemia, often caused by trace element deficiency or cachexia, can also occur.

Haematology and biochemistry in healthy llamas at sea level

In the last years, there has been an increasing interest in llamas, not only as part of a productive system, but mostly as companion animals. Most reports regarding clinical biochemistry and haematology include few llamas and details about their health status are not available. The present study aims to provide haematological and biochemical parameters for llamas of known health status. Twenty-three non-pregnant females and seven males that live in Buenos Aires, Argentina (34°36'S, 58°22'W, at sea level) were studied. Llamas were clinically healthy, in good nutritional status. Animals were kept at grass and were fed hay bale or pellets and water ad libitum. Blood samples were collected by jugular venipuncture in spring. Packed cell volume, leucocyte count, differential white cell count, platelets count, urea, creatinine, total proteins, albumin, alkaline phosphatase, aspartate aminotransferase, alanine aminotransferase, glucose, calcium and phosphate were assessed. No significant differences were observed between males and females, except for platelet count and calcium, which was greater in males (P˂0.01). Values obtained for the different parameters were similar to those previously reported, except for monocytes, alkaline phosphatase, glucose and calcium, that were lower and lymphocytes and platelets count, that were higher in this study. In conclusion, different ambient and methodological conditions might affect some parameters. The parameters hereby presented are representative of llama's population living at sea level in South America.

Applications of Large Language Models in Pathology

Large language models (LLMs) are transformer-based neural networks that can provide human-like responses to questions and instructions. LLMs can generate educational material, summarize text, extract structured data from free text, create reports, write programs, and potentially assist in case sign-out. LLMs combined with vision models can assist in interpreting histopathology images. LLMs have immense potential in transforming pathology practice and education, but these models are not infallible, so any artificial intelligence generated content must be verified with reputable sources. Caution must be exercised on how these models are integrated into clinical practice, as these models can produce hallucinations and incorrect results, and an over-reliance on artificial intelligence may lead to de-skilling and automation bias. This review paper provides a brief history of LLMs and highlights several use cases for LLMs in the field of pathology.

Middle East respiratory coronavirus (MERS-CoV) internalized by llama alveolar macrophages does not result in virus replication or induction of pro-inflammatory cytokines

Severe Middle East respiratory syndrome (MERS) is characterized by massive infiltration of immune cells in lungs. MERS-coronavirus (MERS-CoV) replicates in vitro in human macrophages, inducing high pro-inflammatory responses. In contrast, camelids, the main reservoir for MERS-CoV, are asymptomatic carriers. Although limited infiltration of leukocytes has been observed in the lower respiratory tract of camelids, their role during infection remains unknown. Here we studied whether llama alveolar macrophages (LAMs) are susceptible to MERS-CoV infection and can elicit pro-inflammatory responses. MERS-CoV did not replicate in LAMs; however, they effectively capture and degrade viral particles. Moreover, transcriptomic analyses showed that LAMs do not induce pro-inflammatory cytokines upon MERS-CoV sensing.

Genome-wide scan for runs of homozygosity in South American Camelids

BACKGROUND

Alpaca (Vicugna pacos), llama (Lama glama), vicugna (Vicugna vicugna) and guanaco (Lama guanicoe), are the camelid species distributed over the Andean high-altitude grasslands, the Altiplano, and the Patagonian arid steppes. Despite the wide interest on these animals, most of the loci under selection are still unknown. Using whole-genome sequencing (WGS) data we investigated the occurrence and the distribution of Runs Of Homozygosity (ROHs) across the South American Camelids (SACs) genome to identify the genetic relationship between the four species and the potential signatures of selection.

RESULTS

A total of 37 WGS samples covering the four species was included in the final analysis. The multi-dimensional scaling approach showed a clear separation between the four species; however, admixture analysis suggested a strong genetic introgression from vicugna and llama to alpaca. Conversely, very low genetic admixture of the guanaco with the other SACs was found. The four species did not show significant differences in the number, length of ROHs (100-500 kb) and genomic inbreeding values. Longer ROHs (> 500 kb) were found almost exclusively in alpaca. Seven overlapping ROHs were shared by alpacas, encompassing nine loci (FGF5, LOC107034918, PRDM8, ANTXR2, LOC102534792, BSN, LOC116284892, DAG1 and RIC8B) while nine overlapping ROHs were found in llama with twenty-five loci annotated (ERC2, FZD9, BAZ1B, BCL7B, LOC116284208, TBL2, MLXIPL, PHF20, TRNAD-AUC, LOC116284365, RBM39, ARFGEF2, DCAF5, EXD2, HSPB11, LRRC42, LDLRAD1, TMEM59, LOC107033213, TCEANC2, LOC102545169, LOC116278408, SMIM15, NDUFAF2 and RCOR1). Four overlapping ROHs, with three annotated loci (DLG1, KAT6B and PDE4D) and three overlapping ROHs, with seven annotated genes (ATP6V1E1, BCL2L13, LOC116276952, BID, KAT6B, LOC116282667 and LOC107034552), were detected for vicugna and guanaco, respectively.

CONCLUSIONS

The signatures of selection revealed genomic areas potentially selected for production traits as well as for natural adaptation to harsh environment. Alpaca and llama hint a selection driven by environment as well as by farming purpose while vicugna and guanaco showed selection signals for adaptation to harsh environment. Interesting, signatures of selection on KAT6B gene were identified for both vicugna and guanaco, suggesting a positive effect on wild populations fitness. Such information may be of interest to further ecological and animal production studies.

Use of commercial extenders, with and without the addition of egg yolk, for cooling llama semen

The objective of this study was to evaluate the effect of two commercial extenders, AndroMed® (AM) and Androstar® Plus (AS) both with and without the addition of egg-yolk (EY), for cooling llama semen. A total of sixteen ejaculates were collected from four males. Each ejaculate was divided into four aliquots and diluted with: AM, AM with 20 % EY (AM-EY), AS and AS with 20 % EY (AS-EY) and then cooled to 5 °C in an Equitainer®. Evaluations were carried out in raw semen, after dilution (0 h) and after 24 and 48 h of cooling. Data were analysed using either Friedman or ANOVA. Although total motility decreased in all cooled samples compared to the corresponding 0 h (P < 0.05), the highest percentages were observed in AM-EY being significantly higher than all other cooled samples after 24 h and higher than AS and AS-EY after 48 h. No significant differences were observed in the percentages of live acrosome-intact sperm between extenders at all times tested. A significant decrease in the percentage of sperm membrane osmotic function was observed in samples cooled with AS and AS-EY after 24 and 48 h vs. raw semen and in AM 48 h vs. raw semen. Finally, a significant increase in the percentage of sperm with abnormal tails was observed in the samples cooled with AS and AS-EY. Of all the extenders used, AndroMed® could be considered an option for cooling llama semen and the addition of EY to this extender improves its effectiveness. DATA AVAILABILITY: The data that support the findings of this study are available from the corresponding author upon reasonable request.

Protective efficacy of an RBD-based Middle East respiratory syndrome coronavirus (MERS-CoV) particle vaccine in llamas

Ongoing outbreaks of Middle East respiratory syndrome coronavirus (MERS-CoV) continue posing a global health threat. Vaccination of livestock reservoir species is a recommended strategy to prevent spread of MERS-CoV among animals and potential spillover to humans. Using a direct-contact llama challenge model that mimics naturally occurring viral transmission, we tested the efficacy of a multimeric receptor binding domain (RBD) particle-display based vaccine candidate. While MERS-CoV was transmitted to naïve animals exposed to virus-inoculated llamas, immunization induced robust virus-neutralizing antibody responses and prevented transmission in 1/3 vaccinated, in-contact animals. Our exploratory study supports further improvement of the RBD-based vaccine to prevent zoonotic spillover of MERS-CoV.

Effect of hCG administration on Day 7 post-mating on accessory corpus luteum development and progesterone concentration in llamas

A high embryo loss rate has been reported in llamas. As strategies that lead to an increase in plasma progesterone (P4) concentration might improve fertility, the aim of the present study was to evaluate if the administration of hCG on Day 7 post-mating is useful to develop an accessory corpus luteum (CL), increasing plasma P4 concentration. Twenty (n = 20) female llamas, ranging between 5 and 10 years of age and four (n = 4) males of proven fertility, ranging between 8 and 10 years of age were included in the study. Accessory CL developed in all treated llamas after hCG administration and plasma P4 concentration was significantly greater in treated than in control females (P˂0.0001). The diameter and vascularization of the original CL were not affected by treatment in pregnant llamas. However, in treated non-pregnant llamas, corpus luteum diameter was greater than in the control group from Day 14 post-mating until the end of the study (P˂0.001). In treated llamas, the accessory CL was detected throughout the study in pregnant and non-pregnant females, but its vascularization started to decrease around Day 16 post-mating in non-pregnant animals (P˂0.05). In conclusion, hCG treatment on Day 7 post mating was useful to induce an accessory CL and increase plasma P4 concentration in llamas. Thus, this treatment could be considered as a useful strategy to improve pregnancy rates in llama herds.

Cooled storage of semen from livestock animals (Part II): Camelids, goats, and sheep

This review is part of the Festschrift in honor of Dr. Duane Garner and provides an overview of current techniques in cooled storage of semen from livestock animals such as camelids, goats, and sheep. Facing worldwide environmental changes and a trend towards more conscious and healthy eating behaviors, the development of a stable animal breeding industry is a significant challenge for the near future. In the present review, factors influencing semen handling in camelids, goats and sheep are described and relevant methods as well as current trends to improve liquid-storage of cooled semen are discussed, including extenders, additives, cooling rates, and storage temperatures. The species-specific physiology and resulting challenges are taken into consideration. While the main problem for camelid semen processing is the relatively greater viscosity as compared with that of some other animals, the deciding factor for successful artificial insemination (AI) in goats and sheep is the site (i.e., cervical or vaginal) of semen placement in the reproductive tract. Due to the type of cervical anatomy, the penetration of the cervix when using AI instruments is rather difficult. Furthermore, the seminal plasma of small ruminants affects the interaction with milk-based extenders and egg yolk which results in species-specific regimens for cooled liquid-preservation. Comparing all three species, the greatest pregnancy rates were obtained by AI with goat semen after cooled liquid-storage for several days.

Pain Management in Small Ruminants and Camelids: Analgesic Agents

Small ruminants are increasing in popularity as both production and companion animals in the United States. Among sheep, goats, and camelids, there are many disease processes and management techniques that have the potential to result in painful or noxious stimuli. In these species, many medications and therapeutic techniques can be used to reduce or eliminate the long-term consequences of pain. This review focuses on the commonly used medications available for pain management of small ruminants and discusses the benefits and negative aspects of their use.

Use of Hysteroscopy for Diagnosing Causes of Infertility in Camelids

Hysteroscopy in alpacas and llamas allows for the identification of abnormalities on the surface or within the endometrium that cannot be identified with other methods. Hysteroscopy also allows for site-directed endometrial cytology, culture, and biopsy to achieve a definitive diagnosis. Even when no cause for infertility can be found, previously infertile females tend to become pregnant and maintain their pregnancies to term following the hysteroscopic procedure. This therapeutic effect may be a response to pre-hysteroscopy estrogen treatment, dilation of the uterine horns during hysteroscopy, and/or posttreatment uterine lavages. Complications following hysteroscopy have not been reported in camelids.

Pain Management in Small Ruminants and Camelids: Applications and Strategies

Small ruminants are increasing in popularity as production and companion animals in the United States, and among sheep, goats, and camelids there are many disease processes and management techniques that have the potential to result in painful or noxious stimuli. In these species, many medications and therapeutic techniques can be used to reduce or eliminate the long-term consequences of pain. In this second portion of the review, we focus on the application of pain management in these species. These strategies include mono- and multimodal and the use of precision pain management, such as epidural drug administration, regional perfusions, and transdermal applications.

Dehydration of llama sperm using different osmolarity media and temperatures for preservation

The objective of this study was to evaluate effects of dehydration on sperm DNA with the aim of eventually using this method for preserving llama spermatozoa. Two experiments were conducted: 1) sperm preservation at 5 °C for 60 days in different hyperosmotic solutions (500, 800, 1000 and 1200 mOsmol/l) (n = 6, replications = 2) and 2) sperm preservation at 5 and -20 °C for 60 days in the same hyperosmotic solutions, with supplementary antibiotics (n = 6, replications = 2). Sperm motility, membrane functional integrity, viability and morphology were evaluated at 0 and 48 h of the preservation period (Experiment 1) and at 30 min and 24 h (Experiment 2). Sperm DNA was evaluated at 0 or 30 min (Experiment 1 and 2, respectively) and on days 7, 14, 21, 30 and 60 of the preservation periods. Motility, membrane functional integrity and viability were less when sperm were dehydrated, while sperm cell morphology was not affected. There was a smaller percentage of sperm with condensed chromatin as duration of the preservation period increased when stored in the different hyperosmotic solutions. There was a markedly smaller (P < 0.05) percentage of sperm with intact DNA in all solutions as the duration of preservation increased, with there being greater values for intact DNA at -20 °C than sperm preserved at 5 °C. Llama sperm chromatin condensation was slightly affected by the process of dehydration. There was a markedly smaller percentage of sperm with intact DNA in the dehydrated semen samples.

Prevalence of coat colour traits and congenital disorders of South American camelids in Austria, Germany and Switzerland

BACKGROUND

The increasing popularity of alpacas and llamas outside of South America is undeniable. The associated limited genetic diversity raises questions about health and other genetically determined traits like coat colour. Therefore, a survey studying the prevalence of congenital disorders and coat colours and patterns in South American camelids was performed in Austria, Germany and Switzerland. Moreover, the motivation for keeping these animals, the herd size and breeds was assessed.

RESULTS

A total of 146 questionnaires were returned corresponding to 16 farms from Austria, 69 farms from Germany, and 61 farms from Switzerland. In total, the returned surveys reported data on 2770 animals including ~ 85% alpacas and ~ 15% llamas. The most common alpaca breed was Huacaya (87.7%), the most common llama breed was Wooly (15.6%). Breeding (69.4%), wool production (63.3%) and keeping them as pets (53.7%) were the most common motivations to keep these animals, although this varied among countries. The three coat colour groups, solid white (24.8%), brown and black (64.8%) and grey (10.4%), occurred at different frequencies. About 7% of the South American camelids with solid white coat showed blue-pigmented eyes, corresponding to the known blue-eyed white phenotype, of which more than every second animal was apparently deaf. Uniform solid coloured animals occurred predominantly (81.4%), whereas pinto (8.8%), speckled (6.4%) and spotted (3.4%), also known as appaloosa, were comparably less prevalent. In total 161 observations of congenital disorders occurring during a 5-year-period were reported. The most prevalent disorders were in the group of musculoskeletal disorders such as spiral toe growth (16.4%), hyperextension of the fetlock joint (12.3%), angular limb deformities (11.0%) and axial rotation of the limbs (8.2%).

CONCLUSIONS

This survey revealed first insights into the occurrence of different traits and disorders in the current South American camelid population of Austria, Germany, and Switzerland. The identification of the most common musculoskeletal disorders might encourage the breeders to eliminate affected animals from their breeding program to decrease the incidence although traits such as spiral toe growth might also represent phenocopies.

Treatment of sarcoptic mange in llamas (Lama glama) and alpacas (Vicugna pacos) with repeated subcutaneous moxidectin injections

An outbreak of sarcoptic mange was investigated in a herd of llamas and alpacas in the Black Forrest (Baden-Wuerttemberg, Germany). The diagnosis was made by clinical picture and detection of mites in skin scrapings and ear swabs. At the beginning numerous of Sarcoptes mites were found in the scraping samples. The llamas and alpacas were treated subcutaneously with 0,2 mg/kg bodyweight moxidectin every three weeks (2 mL per llama, 1,5 mL per alpaca). Because of the slow recovery of the South American Camelids it was necessary to repeat the treatment eight times. On days 0, 42, 84, 126, and 168, all animals were examined clinically, and epidermal debris were collected from both auricular areas and other body regions for microscopic examination. The alpacas recovered rapidly and mite counts declined steadily. Llamas showed a slower remission of mite counts and clinical condition. For complete healing of crusting skin reactions, and pruritus six months of treatment were necessary. Therapy of sarcoptic mange in South American Camelids with macrocyclic lactons usually takes a long duration of time.

Genomic analysis of the domestication and post-Spanish conquest evolution of the llama and alpaca

BACKGROUND

Despite their regional economic importance and being increasingly reared globally, the origins and evolution of the llama and alpaca remain poorly understood. Here we report reference genomes for the llama, and for the guanaco and vicuña (their putative wild progenitors), compare these with the published alpaca genome, and resequence seven individuals of all four species to better understand domestication and introgression between the llama and alpaca.

RESULTS

Phylogenomic analysis confirms that the llama was domesticated from the guanaco and the alpaca from the vicuña. Introgression was much higher in the alpaca genome (36%) than the llama (5%) and could be dated close to the time of the Spanish conquest, approximately 500 years ago. Introgression patterns are at their most variable on the X-chromosome of the alpaca, featuring 53 genes known to have deleterious X-linked phenotypes in humans. Strong genome-wide introgression signatures include olfactory receptor complexes into both species, hypertension resistance into alpaca, and fleece/fiber traits into llama. Genomic signatures of domestication in the llama include male reproductive traits, while in alpaca feature fleece characteristics, olfaction-related and hypoxia adaptation traits. Expression analysis of the introgressed region that is syntenic to human HSA4q21, a gene cluster previously associated with hypertension in humans under hypoxic conditions, shows a previously undocumented role for PRDM8 downregulation as a potential transcriptional regulation mechanism, analogous to that previously reported at high altitude for hypoxia-inducible factor 1α.

CONCLUSIONS

The unprecedented introgression signatures within both domestic camelid genomes may reflect post-conquest changes in agriculture and the breakdown of traditional management practices.

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.

Ovulation mechanism in South American Camelids: The active role of β-NGF as the chemical signal eliciting ovulation in llamas and alpacas

The ovulation-inducing effect of seminal plasma was first suggested in Bactrian camels over 30 years ago, initiating a long search to identify the 'ovulation-inducing factor' (OIF) present in camelids semen. During the last decade, primarily in llamas and alpacas, this molecule has been intensively studied characterizing its biological and chemical properties and ultimately identifying it as β-Nerve Growth Factor (β-NGF). The high concentration of OIF/β-NGF in seminal plasma of llamas and alpacas, and the striking effects of seminal fluid on ovarian function strongly support the notion of an endocrine mode of action. Also, have challenged the dogma of mating induced ovulation in camelid species, questioning the classical definition of reflex ovulators, which at the light of new evidence should be revised and updated. On the other hand, the presence of OIF/β-NGF and its ovulatory effect in camelids confirm the notion that seminal plasma is not only a transport and survival medium for sperm but also, a signaling agent targeting female tissues after insemination, generating relevant physiological and reproductive consequences. The presence of this molecule, conserved among induced as well as spontaneous ovulating species, clearly suggests that the potential impacts of this reproductive feature extend beyond the camelid species and may have broad implications in mammalian fertility. The aim of the present review is to provide a brief summary of all research efforts undertaken to isolate and identify the ovulation inducing factor present in the seminal plasma of camelids. Also to give an update of the current understanding of the mechanism of action of seminal β-NGF, at central and ovarian level; finally suggesting possible brain targets for this molecule.

Utility of genetic variation in coat color genes to distinguish wild, domestic and hybrid South American camelids for forensic and judicial applications

A molecular genetic protocol for distinguishing pure and hybrid South American camelids was developed to provide strong, quantifiable, and unbiased species identification. We detail the application of the approach in the context of a criminal case in the Andes Mountains of central Chile where the defendants were alleged to have illegally hunted three wild guanacos (Lama guanicoe), as opposed to hybrid domestic llama (Lama glama)/wild guanaco crosses, which are unregulated. We describe a workflow that differentiates among wild, domestic and hybrid South American camelids (Lama versus Vicugna) based on mitochondrial cytochrome b genetic variation (to distinguish between Lama and Vicugna), and MC1R and exon 4 variation of the ASIP gene (to differentiate wild from domestic species). Additionally, we infer the population origin and sex of each of the three individuals from a panel of 15 autosomal microsatellite loci and the presence or absence of the SRY gene. Our analyses strongly supported the inference that the confiscated carcasses corresponded with 2 male and 1 female guanacos that were hunted illegally. Statistical power analyses suggested that there was an extremely low probability of misidentifying domestic camelids as wild camelids (an estimated 0 % Type I error rate), or using more conservative approached a 1.17 % chance of misidentification of wild species as domestic camelids (Type II error). Our case report and methodological and analytical protocols demonstrate the power of genetic variation in coat color genes to identify hybrids between wild and domestic camelid species and highlight the utility of the approach to help combat illegal wildlife hunting and trafficking.

The effect of seminal plasma β-NGF on follicular fluid hormone concentration and gene expression of steroidogenic enzymes in llama granulosa cells

BACKGROUND

Nerve growth factor (β-NGF) from llama seminal plasma has been described as a potent ovulatory and luteotrophic molecule after intramuscular or intrauterine infusion in llamas and alpacas. We tested the hypothesis that systemic administration of purified β-Nerve Growth Factor (β-NGF) during the preovulatory stage will up-regulate steroidogenic enzymes and Vascular Endothelial Growth Factor (VEGF) gene expression in granulosa cells inducing a change in the progesterone/estradiol ratio in the follicular fluid in llamas.

METHODS

Experiment I: Female llamas (n = 64) were randomly assigned to receive an intramuscular administration of: a) 50 μg gonadorelin acetate (GnRH, Ovalyse, Pfizer Chile SA, Santiago, Chile, n = 16), b) 1.0 mg of purified llama β-NGF (n = 16), or c) 1 ml phosphate buffered saline (PBS, negative control group, n = 16). An additional group of llamas (n = 16) were mated with a fertile male. Follicular fluid and granulosa cells were collected from the preovulatory follicle at 10 or 20 h after treatment (Time 0 = administration of treatment, n = 8/treatment/time point) to determine progesterone/estradiol concentration and steroidogenic enzymes and VEGF gene expression at both time points. Experiment II: Granulosa cells were collected from preovulatory follicles from llamas (n = 24) using ultrasound-guided transvaginal follicle aspiration for in vitro culture to determine mRNA relative expression of Steroidogenic Acute Regulatory Protein (StAR) and VEGF at 10 or 20 h (n = 4 replicates) and progesterone secretion at 48 h (n = 4 replicates) after LH or β-NGF treatment.

RESULTS

Experiment I: There was a significant increase in the progesterone/estradiol ratio in mated llamas or treated with GnRH or purified β-NGF. There was a significant downregulation in the mRNA expression of Aromatase (CYP19A1/P450 Arom) for both time points in llamas mated or treated with GnRH or llama purified β-NGF with respect to the control group. All treatments except β-NGF (20 h) significantly up regulated the mRNA expression of 3-beta-hydroxysteroid dehydrogenase (HSD3B) whereas the expression of StAR and Side-Chain cleavage enzyme (CYP11A1/P450scc) where significantly up regulated only by mating (20 h), or β-NGF at 10 or 20 h after treatment. VEGF was up regulated only in those llamas submitted to mating (10 h) or treated with purified β-NGF (10 and 20 h). Experiment II: Only β-NGF treatment induced an increase of mRNA abundance of StAR from llama granulosa cells at 20 h of in vitro culture. There was a significant increase on mRNA abundance of VEGF at 10 and 20 h of in vitro culture from granulosa cells treated with β-NGF whereas LH treatment increases VEGF mRNA abundance only at 20 h of in vitro culture. In addition, there was a significant increase on progesterone secretion from llama granulosa cells 48 h after LH or β-NGF treatment.

CONCLUSIONS

Systemic administration of purified β-NGF from llama seminal fluid induced a rapid shift from estradiol to progesterone production in the preovulatory follicle. Differences in gene expression patterns of steroidogenic enzymes between GnRH and mated or β-NGF-treated llamas suggest local effects of seminal components on the preovulatory follicle.

Plasma steroid profiles and ovarian response in llamas treated with eCG for superovulation combined with exogenous progesterone during early luteal phase

The objective of this study was to evaluate the effects of plasma progesterone (P₄) concentrations during eCG-ovarian follicular superstimulatory treatment performed in early luteal phase and estradiol concentrations during peri-ovulatory period on ovarian response, number and embryo quality. On Day -2, females (n = 75) having a follicle ≥7 mm were treated with GnRH to induce ovulation. On Day 0, females that had ovulations (n = 54) were treated with 1000 IU eCG and were assigned to one of two treatments: (1) intravaginal device (ID) containing 0.5 g P₄ (P₄ group) and (2) no ID (Control group). On Day 5, females were administered PGF_2α and the ID was removed. On Day 7 and 8, females were mated and embryo recovery was performed 7 or 8 days later. Blood samples were collected from Day 0 to 9. Number (± SD) of follicles ≥7 mm on day of mating was greater (P =  0.04) in the control (9.7 ± 4.2) than P₄-treated (6.7 ± 4.9) group; number of corpora lutea did not differ (5.5 ± 3.1 and 5.2 ± 3.4 respectively). Ovulation rate was greater (P <  0.01) in the P₄-group (77.4%; 130/168) than control group (53.3%; 135/253). Number of embryos with an excellent grade (grade 1) tended to be greater (P =  0.07) in the P₄-group (82.4%; 42/51) than control group (65.4%; 36/55). It was concluded that supplementation with exogenous P₄ during eCG treatment in early luteal phase inhibits excessive follicular growth, increases ovulation rate and improves embryo quality.

Llama peripheral B-cell populations producing conventional and heavy chain-only IgG subtypes are phenotypically indistinguishable but immunogenetically distinct

Camelid ungulates produce homodimeric heavy chain-only antibodies (HCAbs) in addition to conventional antibodies consisting of paired heavy and light chains. In the llama, HCAbs are made up by at least two subclasses (long-hinge IgG2b and short-hinge IgG2c HCAbs vs. conventional heterotetrameric IgG1s). Here, we generated murine monoclonal antibodies (mAbs) specific for the hinge-C_H2 boundary of llama IgG2b (mAb 1C10) and the Fc of llama IgG2c HCAbs (mAb 5E4). Flow cytometric analysis of llama peripheral blood lymphocytes revealed that IgG1⁺, IgG2b⁺ and IgG2c⁺ B cells could be distinguished using mAbs 1C10/5E4 but had equivalent expression of three other cell-surface markers. MiSeq sequencing of the peripheral B cell repertoires of three llamas showed that (i) IgG2b and IgG2c HCAbs were present in similar proportions in the repertoire, (ii) a subset of IgG2b and IgG2c HCAbs, but not IgG1s, entirely lacked a hinge exon and showed direct V_HH-C_H2 splicing; these "hingeless" HCAbs were clonally expanded, somatically mutated and derived from hinged HCAb precursors, (iii) substantial repertoire overlap existed between IgG subclasses, especially between IgG2b and IgG2c HCAbs, (iv) the complementarity-determining region (CDR)-H3 length distributions of IgG2b and IgG2c HCAbs were broader and biased towards longer lengths compared with IgG1s due to increased N-nucleotide addition, (v) IgG2b and IgG2c HCAbs used a more restricted set of IGHV genes compared with IgG1s, and (vi) IgG2b and IgG2c HCAbs had elevated somatic mutations rates of both CDRs and framework regions (FRs) compared with IgG1s, especially of CDR-H1 and FR3. The distinct molecular features of llama IgG1, IgG2b and IgG2c antibodies imply that these subclasses may have divergent immunological functions and suggest that specific mechanisms operate to diversify HCAb repertoires in the absence of a light chain.

Ocular Surface Disease in New World Camelids

This article discusses the anatomy, physiology, and common disease affecting the ocular surface of New World camelids, llamas, and alpacas.

Sarcocystosis in South American camelids: The state of play revisited

Members of the genus Sarcocystis (Apicomplexa: Sarcocystidae) are intracellular protozoan parasites that infect a wide range of domestic and wild animals, resulting in economic losses in production animals worldwide. Sarcocystis spp. have indirect life-cycles where canids and felids serve as main definitive hosts while a range of domestic and wild animals serve as intermediate hosts, including South American camelids (SACs) such as alpacas, llamas and guanacos. These animals primarily occur in South American countries on Andean, elevated plains but in recent years, alpacas and llamas have become emerging animal industries in other parts of the world such as Australia, Europe and the USA due to their high-quality fiber, meat and hides. For instance, alpaca meat is becoming popular in many parts of the world due to its lower cholesterol content than other red meat, thereby it has the potential of a valuable product for both local and international markets. However, SAC meat can be degraded and/or even condemned due to the presence of macroscopic sarcocysts in skeletal muscles, leading to significant economic losses to farmers. The infection is generally asymptomatic, though highly pathogenic or even fatal Sarcocystis infections have also been reported in alpacas and llamas. Despite the economic importance of sarcocystosis in SACs, little is known about the life-cycle of parasites involved, disease transmission, epidemiology, pathogenesis, diagnosis, control and public health significance. This review article provides an in-depth analysis of the existing knowledge on the taxonomy, epidemiology, clinicopathology and diagnosis of Sarcocystis in SACs, highlights knowledge gaps and proposes future areas of research that could contribute to our better understanding of sarcocystosis in these animals.

Seropositivity to Sarcocystis infection of llamas correlates with breeding practices

Production of llama (Lama glama) meat in rural communities of the Andean regions is largely affected by Sarcocystis spp. infection. Macroscopic cysts develop in muscles as a consequence of S. aucheniae parasitism, often resulting in meat downgrade or condemnation. Llama meat production is informal in Argentina but has broad perspectives for improvement, and would significantly benefit from the development of standardized control methodologies. This work analyzes whether the presence of anti-Sarcocystis spp. antibodies in llamas is influenced by factors such as geographic region and/or herd management practices. To this aim, an indirect ELISA was set up based on a ~23kDa soluble immunogenic protein fraction (Sa23), isolated from S. aucheniae macrocysts (Sa23-iELISA). Serum samples (n=507) were collected from llamas bred under three different conditions: (i) with no sanitation controls and in the presence of pastoral dogs by small producers of different localities of the Argentine Puna (Group I, n=237); (ii) with sanitation controls and no pastoral dogs, in fenced fields of an experimental agricultural station in the Argentine Puna (Group II, n=167); and (iii) with sanitation controls and no pastoral dogs in fenced fields of farms of the humid Pampas (Group III, n=103). Results of the Sa23-iELISA were expressed as percentages of positivity with respect to a reference Sarcocystis-positive serum. Notably, the percentage of sera that fell above the cut-off (31.5% positivity) in group (i) was significantly higher (p<0.001) than those of groups (ii) and (iii) (50% vs 23% and 26%, respectively). These results indicate that herd management practices constitute a critical risk factor for sarcocystiosis in llamas. Differences in these practices include feeding of dogs with raw Sarcocystis-infected llama meat, with the consequent maintenance of the parasite life cycle by the contamination of pastures and water with fecal-derived infective oocysts/sporocysts. Additionally, the itinerancy of llama herds in search for pastures and water sources possibly exposes animals to a higher number of infective foci. On the other hand, percentages of seropositive llamas kept under controlled conditions in the Puna or the humid Pampas were not significantly different, suggesting that climate, altitude, and/or pasture characteristics do not influence Sarcocystis-infection. Male gender and older age of llamas were found to be propensity factors for sarcocystiosis in llamas bred in La Puna under controlled conditions. Availability of diagnostic tools, as well as increased knowledge on the parasite and its epidemiology, will allow the design of control strategies for SAC sarcocystiosis.

Nerve growth factor from seminal plasma origin (spβ-NGF) increases CL vascularization and level of mRNA expression of steroidogenic enzymes during the early stage of Corpus Luteum development in llamas

The objectives of the study were to determine the effect of seminal plasma β-NGF on Corpus Luteum morphology and function and level of mRNA expression of steroidogenic enzymes. Llamas were assigned (n = 12/per group) to receive an intramuscular dose of: (a) 1 ml phosphate buffered saline (PBS), (b) 5 μg gonadorelin acetate (GnRH), or (c) 1.0 mg of purified llama spβ-NGF. Ovaries were examined by transrectal B-mode ultrasonography from treatment to ovulation (Day 0 = treatment). B mode/Power Doppler ultrasonography and blood samples collection were performed at Days 4, 8 and 10 (n = 3 llamas per treatment group/per time point) to determine CL diameter, vascularization and plasma progesterone concentration respectively. Plasma progesterone concentration was analyzed in all llamas at Day 0. Then females were submitted to ovariectomy at Days 4, 8 and 10 (n = 3 llamas/treatment/time), CL was removed to determine vascular area, proportion of luteal cells and CYP11A1/P450scc and STAR expression by RT-PCR. Ovulation was similar between llamas treated with GnRH or spβ-NGF and CL diameter did not differ between GnRH or spβ-NGF groups by Day 4, 8 or 10. Vascularization area of the CL was higher (P < 0.01) in llamas from the spβ-NGF than GnRH-treated group by Day 4 and 8. Plasma progesterone concentration was higher (P < 0.05) in llamas from the spβ-NGF compared to females of GnRH group by Day 4 and 8. The proportion of small and large luteal cells did not differ between GnRH or spβ-NGF groups by Day 8. CYP11A1/P450scc was upregulated 3 folds at day 4 and 10 by spβ-NGF compared to GnRH. STAR transcription was 3 folds higher at day 4 in females treated with spβ-NGF. In conclusion, the luteotrophic effect of spβ-NGF could be related to an increase of vascularization and up regulation of CYP11A1/P450scc and STAR transcripts enhancing progesterone secretion.

Validation of the FAMACHA© system in South American camelids

Haemonchus contortus resistant to multiple anthelmintics threaten the viability of the small ruminant industry in areas where this parasite is prevalent. In response to this situation, the FAMACHA© system was developed and validated for use with small ruminants as a way to detect clinical anemia associated with haemonchosis. Given that H. contortus and multiple anthelmintic resistance is a similar problem in camelids, the FAMACHA© system might also provide the same benefits. To address this need, a validation study of the FAMACHA© system was conducted on 21 alpaca and llama farms over a 2-year period. H. contortus was the predominant nematode parasite on 17 of the 21 farms (10 alpaca and 7 llama farms) enrolled in the study, based on fecal culture results. The FAMACHA© card was used to score the color of the lower palpebral (lower eye lid) conjunctiva on a 1-5 scale. Packed cell volume (PCV) values were measured and compared to FAMACHA© scores using FAMACHA© score cutoffs of ≥3 or ≥4 and with anemia defined as a PCV ≤15%, ≤17%, or≤20%. PCV was significantly associated with FAMACHA© score, fecal egg count (FEC), and body condition score (BCS), regardless of the FAMACHA© cutoff score or the PCV% chosen to define clinical anemia (p<0.01 in all cases). The use of FAMACHA© scores ≥3 and PCV ≥ 15% indicating anemia provided the best sensitivity (96.4% vs 92.9% for FAMACHA© ≥4), whereas FAMACHA scores ≥ 4 and PCV ≤20% provided the best specificity (94.2% vs 69.1% for FAMACHA© ≥3). The data from this study support the FAMACHA© system as a useful tool for detecting clinical anemia in camelids suffering from haemonchosis. Parameters for making treatment decisions based on FAMACHA© score in camelids should mirror those established for small ruminants.

Evaluation of a panel of antibodies for the immunohistochemical identification of immune cells in paraffin-embedded lymphoid tissues of new- and old-world camelids

Different species of camelids play an important role in the epidemiology of various emerging infectious diseases such as Middle East respiratory syndrome. For precise investigations of the immunopathogenesis in these host species, appropriate immunohistochemical markers are highly needed in order to phenotype distinct immune cells populations in camelids. So far, specific immunohistochemical markers for camelid immune cells are rarely commercially available, and cross-reactivity studies are restricted to the use of frozen dromedary tissues. To bridge this gap, 14 commercially available primary antibodies were tested for their suitability to demonstrate immune cell populations on formalin fixed paraffin-embedded (FFPE) tissue sections of dromedaries, Bactrian camels, llamas, and alpacas in the present study. Out of these, 9 antibodies directed against CD3, CD20, CD79α, HLA-DR, Iba-1, myeloid/histiocyte antigen, CD204, CD208, and CD68 antigen exhibited distinct immunoreaction patterns to certain camelid immune cell subsets. The distribution of these antigens was comparatively evaluated in different anatomical compartments of thymus, spleen, mesenteric, and tracheobronchial lymph nodes. The presented results will provide a basis for further investigations in camelids, especially with respect to the role of the immune response in certain infectious diseases, which harbor a considerable risk to spill over to other species.

Culicoides vector species on three South American camelid farms seropositive for bluetongue virus serotype 8 in Germany 2008/2009

Palearctic species of Culicoides (Diptera, Ceratopogonidae), in particular of the Obsoletus and Pulicaris complexes, were identified as putative vectors of bluetongue virus serotype 8 (BTV-8) on ruminant farms during the epizootic in Germany from 2006 to 2009. BTV may cause severe morbidity and mortality in ruminants and sporadically in South American camelids (SAC). However, the fauna of Culicoides spp. on SAC farms has not been investigated. Therefore, the ceratopogonid fauna was monitored on three farms with BTV-seropositive SAC in Germany. Black-light traps were set up on pastures and in stables from summer 2008 to autumn 2009. Additionally, ceratopogonids were caught in emergence traps mounted on llama dung and dung-free pasture from spring to autumn 2009. After morphological identification, selected Culicoides samples were analysed for BTV-RNA by real-time RT-PCR. The effects of the variables 'location', 'temperature' and 'humidity' on the number of Culicoides caught in black-light traps were modelled using multivariable Poisson regression. In total, 26 species of Culicoides and six other genera of biting midges were identified. The most abundant Culicoides spp. collected both outdoors and indoors with black-light traps belonged to the Obsoletus (77.4%) and Pulicaris (16.0%) complexes. The number of Culicoides peaked in summer, while no biting midges were caught during the winter months. Daily collections of Culicoides were mainly influenced by the location and depended on the interaction of temperature and humidity. In the emergence traps, species of the Obsoletus complex predominated the collections. In summary, the absence of BTV-RNA in any of the analysed Culicoides midges and in the BTV-seropositive SAC on the three farms together with the differences in the pathogenesis of BTV-8 in SAC compared to ruminants suggests a negligible role of SAC in the spread of the virus. Although SAC farms may provide similar suitable habitats for putative Culicoides vectors than ruminant farms, the results suggest that geographic and meteorological factors had a stronger influence on Culicoides abundance than the animal species.

Atrial Fibrillation in Eight New World Camelids

Background

There is limited information on the incidence of clinical signs, concurrent illness and treatment options for atrial fibrillation (AF) in New World Camelids (NWC).

Objective

Describe clinical signs and outcome of AF in NWC.

Animals

Eight New World Camelids admitted with AF.

Methods

A retrospective observational study of camelids diagnosed with AF based on characteristic findings on electrocardiogram (ECG).

Results

All animals had an irregularly irregular heart rhythm detected on physical examination and 4 cases had obtunded mentation on admission. Three camelids were diagnosed with AF secondary to oleander intoxication, 3 animals had underlying cardiovascular disease, 1 was diagnosed with lone AF and 1 had AF diagnosed on examination for a urethral obstruction. Five of eight animals survived to discharge and nonsurvivors consisted of animals which died or were euthanized as a result of cardiovascular disease (2/8) or extra‐cardiac disease unrelated to the AF (1/8).

Conclusions and Clinical Importance

Atrial fibrillation occurs in NWC in association with cardiovascular disease, extra‐cardiac disease or as lone AF. Amiodarone and transthoracic cardioversion were attempted in one llama with lone AF, but were unsuccessful. Atrial fibrillation was recorded in 0.1% of admissions.

Llamas and alpacas in Europe: Endoparasites of the digestive tract and their pharmacotherapeutic control

There are distinctive specifications for veterinary medical care of South American camelids (SACs), namely, llamas, alpacas, vicunas and guanacos. Camelids are classified as food-producing animals, but as veterinary medicinal products are often only licensed for domestic food-producing species such as horses, goats, sheep and cattle, treatment of SACs generally requires off-label use of drugs. Endoparasitism is a major health concern in camelids and can result in severe clinical diseases and economic losses. There is still a lack of work on the pharmacokinetics, safety and efficacy for most antiparasitic drugs used in SACs. Even when choosing an appropriate route of administration, several aspects must be considered such as the fact that pour-on formulations are largely ineffective in camelids due to the unique features of llama and alpaca skin and hair that result in extremely low drug bioavailability. This review focuses on the main endoparasites of the digestive tract in llamas and alpacas in Europe and pharmacotherapeutic options based on current knowledge.

Hematology of camelids

Interpretation of camelid hematology results is similar to that of other mammals. Obtaining accurate results and using appropriate reference intervals can be a bit problematic, particularly when evaluating the erythron. Camelid erythrocytes vary from other mammals in that they are small, flat, and elliptical. This variation makes data obtained from samples collected from these species prone to error when using some automated instruments. Normal and abnormal findings in camelid blood are reviewed as well as how to ensure accurate results.

Fluid therapy in small ruminants and camelids

Body water, electrolytes, and acid-base balance are important considerations in the evaluation and treatment of small ruminants and camelids with any disease process, with restoration of these a priority as adjunctive therapy. The goals of fluid therapy should be to maintain cardiac output and tissue perfusion, and to correct acid-base and electrolyte abnormalities. Hypoglycemia, hyperkalemia, and acidosis are the most life-threatening abnormalities, and require most immediate correction.

Review of laboratory submissions from New World camelids in England and Wales (2000-2011)

Sample submissions to the Animal Health and Veterinary Laboratories Agency's (AHVLA's) diagnostic laboratory network in England and Wales were reviewed for diseases affecting New World camelids (NWCs). In the years 2000-2011, 6757 submissions were analysed, including 5154/6757 (76.3%) for diagnosing a disease problem and 1603/6757 (23.7%) for monitoring (no clinical disease). Wasting (weight loss, ill-thrift) was the most commonly reported clinical sign across all age groups. A diagnosis was reached for 1765/5154 (34.2%) diagnostic submissions. The proportion of submissions with diagnoses was higher for carcasses than non-carcass samples and multiple diagnoses were more likely to be reached from carcasses. Parasitic diseases were collectively the most common problem, including parasitic gastroenteritis (319/1765, 18.2%), coccidiosis (187/1765, 10.6%), fascioliasis (151/1765, 8.6%), ectoparasitic infestations (86/1765, 4.9%) and cryptosporidiosis (24/1765, 1.4%). The most frequently diagnosed non-parasitic problems included nutritional diseases (182/1765, 10.3%), septicaemia (104/1765, 5.9%, including 45 cases of colisepticaemia), gastric ulceration (79/1765, 4.5%), tumours/neoplastic diseases (65/1765, 3.7%), tuberculosis (57/1765, 3.2%), clostridial diseases (44/1765, 2.5%), congenital anomalies (41/1765, 2.3%), peritonitis (39/1765, 2.2%) and Johne's disease (20/1765, 1.1%).

Luteotrophic effect of ovulation-inducing factor/nerve growth factor present in the seminal plasma of llamas

The hypothesis that ovulation-inducing factor/nerve growth factor (OIF/NGF) isolated from llama seminal plasma exerts a luteotrophic effect was tested by examining changes in circulating concentrations of LH and progesterone, and the vascular perfusion of the ovulatory follicle and developing CL. Female llamas with a growing follicle of 8 mm or greater in diameter were assigned randomly to one of three groups (n = 10 llamas per group) and given a single intramuscular dose of PBS (1 mL), GnRH (50 μg), or purified OIF/NGF (1.0 mg). Cineloops of ultrasonographic images of the ovary containing the dominant follicle were recorded in brightness and power Doppler modalities. Llamas were examined every 4 hours from the day of treatment (Day 0) until ovulation, and every other day thereafter to Day 16. Still frames were extracted from cineloops for computer-assisted analysis of the vascular area of the preovulatory follicle from treatment to ovulation and of the growing and regressing phases of subsequent CL development. Blood samples were collected for the measurement of plasma LH and progesterone concentrations. The diameter of the dominant follicle at the time of treatment did not differ among groups (P = 0.48). No ovulations were detected in the PBS group but were detected in all llamas given GnRH or OIF/NGF (0/10, 10/10, and 10/10, respectively; P < 0.0001). No difference was detected between the GnRH and OIF/NGF groups in the interval from treatment to ovulation (32.0 ± 1.9 and 30.4 ± 5.7 hours, respectively; P = 0.41) or in maximum CL diameter (13.1 ± 0.4 and 13.5 ± 0.3 mm, respectively; P = 0.44). The preovulatory follicle of llamas treated with OIF/NGF had a greater vascular area at 4 hours after treatment than that of the GnRH group (P < 0.001). Similarly, the luteal tissue of llamas treated with purified OIF/NGF had a greater vascular area than that of the GnRH group on Day 6 after treatment (P < 0.001). The preovulatory surge in plasma LH concentration began, and peaked 1 to 2 hours later in the OIF/NGF group than in the GnRH group (P < 0.05). Plasma progesterone concentration was higher on Day 6 in the OIF/NGF group than in the GnRH group (P < 0.001). Results support the hypothesis that OIF/NGF exerts a luteotrophic effect by altering the secretion pattern of LH and enhancing tissue vascularization during the periovulatory period and early stages of CL development.

Neonatal diarrhea in llamas and alpacas

Diarrhea is an important cause of morbidity in neonatal llamas and alpacas. Diarrhea may be multifactorial in etiology including management and nutritional factors as well as a variety of pathogens. Most of the pathogens involved affect other livestock species and some have host-adapted strains. However, the clinical signs, their expected severity and age of onset of disease varies between species in some cases. The most common pathogens causing diarrhea in neonatal camelids are coronavirus, Escherichia coli (E. coli), Cryptosporidium spp., Giardia spp. and coccidia. The purpose of this paper is to review the available literature on neonatal diarrhea in camelids and to present clinical data from 55 cases seen at The Ohio State University.