Female Alpaca Research Articles

Robust encoding of acoustic identity in alpaca hums – a basis for individual recognition

ABSTRACT Individual recognition is an important element of social interactions among animals. While the presence of individually distinct vocalisations (providing a basis for individual recognition) has been widely tested across species, information about which components of a call encode this information is lacking. We investigated whether female alpaca (Vicugna pacos) vocalisations, particularly their hums, encode information about individual identity and explored which parameters contribute to this encoding. We recorded vocalisations from 9 adult female alpaca and extracted both spectro-temporal features (frequencies and duration) and mel-frequency cepstral coefficients (MFCC). Random forest analyses revealed clear individual differences in both datasets, with the spectro-temporal features allowing for slightly more accurate classification than MFCC (71% and 66.5% accuracy for spectro-temporal features and MFCC, respectively). These robust acoustic identities have the potential to provide a basis for individual recognition in alpaca, which could have important flow-on effects for alpaca communication, as it allows receivers to modulate their response to the callers’ identity. Alpaca, as herd-living and vocal animals, provide an excellent model system for better understanding the mechanisms, causes and consequences of recognition and inter-individual communication.

Use of cardiac gated computed tomography in the diagnosis of a rare congenital cardiovascular anomaly in an adult alpaca.

A 5-year-old female alpaca was presented with respiratory distress and lethargy. Thoracic radiographs revealed a cranioventrally distributed alveolar pattern, caudodorsal bronchial pattern, cardiomegaly, increased soft tissue opaque content in the ventral thorax, and rounded soft tissue opaque structures craniodorsal to the carina. Cardiac gated CT demonstrated a patent ductus arteriosus, ventricular septal defect, complete left atrioventricular valve atresia, partial anomalous venous connections from the cranial pulmonary veins to the azygous and cranial vena cava, severe right-sided cardiomegaly, pleural and peritoneal fluid, and severe hepatic congestion. These findings were confirmed with necropsy.

Assessing colostral and serum immunoglobulin G in alpacas using Brix refractometry and total serum protein

The adequate transfer of passive immunity is a critical factor in neonatal development and survivability. Although well documented in the dairy and equine industries, the recognition of inadequate immunoglobulin transfer on-farm and its impact on the ability of alpaca cria to thrive is largely unknown. Colostrum samples were collected from female alpaca within 24 h of parturition by the owners and whole blood collected from cria by the investigators between 1 and 7 days of age. Direct IgG concentration of milk and serum was determined using radial immunodiffusion assay (RID) and was indirectly estimated using optical and digital Brix refractometry for total solids and clinical refractometry for total serum protein. There was a strong correlation between optical and digital Brix refractometry, and colostral IgG concentration determined by RID. There was a moderate correlation between serum IgG concentration determined by RID and total serum protein in crias. Optical and digital Brix refractometry for colostral IgG estimation and total serum protein for serum IgG estimation are reliable, accurate and easy-to-use tools that can be used on-farm by trained, competent technicians to assess a failure of passive transfer in alpacas. A pilot study at one property only was performed, due to COVID-19 travel restriction interference. Further research is required to determine the reference intervals for these tools to be practical.

Effective treatment of sarcoptic mange in an alpaca (Vicugna pacos) using fluralaner: a case report

South American Camelids, including alpacas, have gained popularity in Europe as pets and prized wool sources. Skin health concerns, particularly mite infestations, have emerged as a notable problem in these animals. Sarcoptic mange can lead to severe itching, papules, and chronic symptoms such as alopecia, crusts, and emaciation if left untreated. This case report documents a 2-year-old female alpaca suffering from sarcoptic mange. Despite initial treatment with ivermectin, its condition worsened, leading to severe weight loss, abortion, and a continued presence of mites. Considering the lack of effective treatments for sarcoptic mange in alpacas and the unavailability of registered drugs for this species in Italy, fluralaner, a drug previously used in other animal species, has been administered orally at a dosage of 5 mg/kg. Within a week after the treatment with fluralaner, the patient exhibited significant improvement, including the resolution of itching, healing of skin lesions, and an increase in appetite. Follow-up skin scrapings confirmed the absence of mites, and the patient’s condition continued to improve. Fluralaner demonstrated to be a highly effective and fast-acting treatment for sarcoptic mange in alpacas, offering potential economic benefits attributed to its single-dose administration.

Diaphragmatic hernia in a female alpaca (Vicugna pacos)

A 3-year-old pregnant female alpaca was noticed due to increased lying and decreased feed intake after shearing. Twelve days after shearing, she aborted an almost completely developed cria. After another two days, the alpaca was recumbent and subsequently died during transport to the clinic. A dissection of the carcass revealed a diaphragmatic hernia. Diaphragmatic hernias have been described in many different species, diagnosis can be made by radiography or ultrasound. Depending on the extent, surgical therapy may be successful.

Necrotising myositis caused by Clostridium clostridioforme and Clostridium difficile in an alpaca following grain overload

AbstractA 4‐year‐old, female alpaca developed necrotising myositis caused by Clostridium difficile and Clostridium clostridioforme, a clostridia spp. previously unknown to affect camelids, shortly after an event of grain overload. The affected leg was amputated due to the aggressive necrosis. This case reports an interesting sequelae of grain overload in camelids, as well as highlights the presence of bacteria not previously known to be pathogenic in camelids and that may need to be further considered in the list of pathogens of South American camelids.

Uterine prolapse in an alpaca – a case report

Disturbances of the postpartum period can occur in all female livestock, of which uterine prolapse is the most commonly diagnosed. The author decided to describe his own case of uterine prolapse in a female alpaca and one of the possible treatments. Knowing the reasons for its occurrence and performing appropriate and quick therapy reduces the risk of consequences resulting from later and occasionally an incorrect diagnosis and treatment. It also contributes to the preservation of proper subsequent female oestrus cycles, and its fertility.

Left displacement of the third gastric compartment in an alpaca: the first case report in China

BackgroundLeft displacement of the third gastric compartment (LDC3) in alpacas is an extremely rare condition and has not been reported thus far. Therefore, we describe the clinical diagnosis and treatment of LDC3 in an alpaca.Case presentationA 2-year-old brown female alpaca (Vicugna pacos) was presented to evaluate a 3-day history of abdominal distension causing loss of both appetite and thirst, along with oliguria and low to no defecation. Clinical examination, X-ray examination, surgical exploration, and determination of gastric pH (pH ~ 2.35) confirmed that LDC3 resulted in abdominal distension. The gastric wall of the displaced third gastric compartment was incised for the expulsion of pneumatosis, and a medical-grade silicone tube was inserted into the incision to remove the effusion by siphoning. Surgical treatment proved to effectively alleviate the abdominal distension caused by LDC3 without apparent side effects.ConclusionsTo our knowledge, this case is the first known report of LDC3 in an alpaca in China. A similar condition, left displaced abomasum, has previously been described in cattle and sheep.

Nerve stimulation‐guided femoral and sciatic blocks in an alpaca (Vicugna pacos) for the removal of a sequestrum from the distal femur

AbstractA 2‐year‐old female intact huacaya alpaca weighing 66.6 kg presented for the removal of a bone sequestrum from the distal femur. Nerve stimulator‐guided femoral and sciatic nerve blocks were applied to provide analgesia for distal femoral surgery. The blocks were simple to perform using existing equipment and current techniques translated from small animals. The techniques reported here for both femoral and sciatic nerve blocks in an alpaca can be used as an alternative to an ultrasound‐guided approach, especially in field situations where additional expensive equipment may not be available or desirable.

Atresia coli in a 1‐day‐old cria

AbstractA 1‐day‐old female alpaca cria presented to Cornell University's large animal internal medicine service for abdominal pain. On presentation, the cria appeared septic with hyperemic mucous membranes and marked abdominal distention. Abdominal ultrasound showed distended, hypomotile loops of small intestine with increased anechoic free peritoneal fluid. Abdominal radiographs with a barium enema showed gas distended proximal colon and marked segmental narrowing of the descending colon. Abdominal exploratory surgery revealed a meconium‐filled blind end in the proximal loop of the ascending colon and a collapsed, empty spiral and descending colon, consistent with a diagnosis of atresia coli. The location of this cria's atresia coli differed in location from the more commonly reported atretic spiral colon lesions seen in calves and was associated with poor surgical prognosis. This species variation is an important consideration prior to surgery and may help inform surgical decisions for those faced with similar cases in the future.

Mammary carcinoma in a geriatric alpaca

An 18-year-old intact, non-lactating, female alpaca presented to the Iowa State University Lloyd Veterinary Medical Center Food Animal and Camelid Hospital for assessment of an inguinal mass noted 2 days prior to shearing. The alpaca was historically multiparous, with her last cria born approximately 1 year prior. On physical exam an 18-centimeter, ulcerated, non-painful mass which produced a thick, white, purulent material and significant crusting was noted in the inguinal region; no normal mammary tissue was appreciated. Clinical differentials were mammary abscess or mammary tumor, the latter of which has not been reported in alpacas. Due to age, cost of therapy and poor prognosis for complete recovery, the owners elected for humane euthanasia and necropsy without further antemortem diagnostic workup. On gross necropsy, the mass was determined to be heterogenous, multilobulated, necrotic and ulcerated with viscous tan to white exudate (Figure 1). Additional findings included multifocal to coalescing pleural nodules and moderate, diffuse lymphadenomegaly of the right inguinal lymph node and mammary lymph node, both of which lacked corticomedullary distinction. On histopathology, a unencapusulated, multilobulated, poorly demarcated, infiltrative neoplasm was diagnosed which completely effaced and replaced normal mammary tissue. Neoplastic cells were epithelial in origin and arranged in nests, islands and tubuloacinar structures, the latter of which contained eosinophilic secretory material (Figure 2). The neoplasm is composed of large polygonal cells arranged in nests, lobules and well differentiated tubules. Neoplastic polygonal cells have distinct cellular borders and abundant hyalinized eosinophilic cytoplasm. Nuclear morphology is characterized by one round hypochromic nucleus per cell, 1–2 nucleoli per nucleus and fine chromatin stippling. There is moderate to marked anisocytosis and anisokaryosis observed throughout the mass. The mitotic index is 5–6 mitotic figures per high power field (0.237 mm2). Multifocal areas of necrosis, inflammation and lymphatic invasion were present throughout with scant areas of normal mammary tissue. The right inguinal lymph node demonstrated regional metastasis but no histopathological evidence of distant metastasis including to the lungs was detected. Here, we report a case of mammary carcinoma in an alpaca. Final diagnosis could not be distinguished between simple tubular carcinoma or mammary ductal carcinoma due to the anaplastic nature of the neoplasm. Previously reported neoplasms in alpacas include fibroma, fibropapilloma, lymphoma, interstitial cell tumor, primitive stromal cell tumor, pancreatic adenocarcinoma, and carcinoma of bronchoalveolar, ocular and of undifferentiated origin.1, 2 Mammary carcinoma of ductal origin has previously been reported in a llama but that case was associated with significant distant metastasis.3 This is the first report of a mammary carcinoma in an alpaca, and it should be considered a differential in future diagnostic investigations of mammary masses. While metastasis to loco-regional lymph nodes was present, distant metastasis was not and may not be the primary concern in future alpacas with mammary neoplasms.

Pulmonary adenocarcinoma in two alpacas (Vicugna pacos)

We describe here two cases of pulmonary neoplasia in alpacas: case 1 was a 19-year-old female huacaya alpaca that was submitted to investigate sudden death with possible previous weight loss....

Management of a geriatric alpaca with multiple neoplasms in a zoological setting

During a routine health check, a 22‐year‐old female alpaca presented with an infected mass on the sternal pad. A squamous cell carcinoma was diagnosed on histopathology. Systemic antibiotics and topical treatment were initiated. Thoracic radiographs and blood analysis showed no abnormalities; therefore, surgical resection was performed, and the wound was allowed to heal by second intention with therapeutic laser therapy. The treatment plan for this animal was developed with the collaboration of the keeping team and zoo managers and considered the health status of the animal, overall prognosis and the possibility of frequent restraints with minimal stress. Six months after initial presentation, the alpaca showed dramatic weight loss and severe urine scalding with a mass identified in the urinary bladder and was euthanased on welfare grounds. Postmortem findings included squamous cell carcinoma metastases in the tributary lymph nodes and in the lung, adenocarcinoma in the lung, and a polyp in the urinary bladder.

Pain management of a mandibular fracture in an alpaca (Vicugna pacos) via epidural catheter placement in the mandibular foramen

A nine-year-old female alpaca with a history of a recurrent tooth root abscess presented for further investigation of a swelling of the left mandible and possible tooth extraction. During the...

Chromosome-Level Alpaca Reference Genome VicPac3.1 Improves Genomic Insight Into the Biology of New World Camelids.

The development of high-quality chromosomally assigned reference genomes constitutes a key feature for understanding genome architecture of a species and is critical for the discovery of the genetic blueprints of traits of biological significance. South American camelids serve people in extreme environments and are important fiber and companion animals worldwide. Despite this, the alpaca reference genome lags far behind those available for other domestic species. Here we produced a chromosome-level improved reference assembly for the alpaca genome using the DNA of the same female Huacaya alpaca as in previous assemblies. We generated 190X Illumina short-read, 8X Pacific Biosciences long-read and 60X Dovetail Chicago® chromatin interaction scaffolding data for the assembly, used testis and skin RNAseq data for annotation, and cytogenetic map data for chromosomal assignments. The new assembly VicPac3.1 contains 90% of the alpaca genome in just 103 scaffolds and 76% of all scaffolds are mapped to the 36 pairs of the alpaca autosomes and the X chromosome. Preliminary annotation of the assembly predicted 22,462 coding genes and 29,337 isoforms. Comparative analysis of selected regions of the alpaca genome, such as the major histocompatibility complex (MHC), the region involved in the Minute Chromosome Syndrome (MCS) and candidate genes for high-altitude adaptations, reveal unique features of the alpaca genome. The alpaca reference genome VicPac3.1 presents a significant improvement in completeness, contiguity and accuracy over VicPac2 and is an important tool for the advancement of genomics research in all New World camelids.

Intracranial abscess formation in an adult alpaca: a case report

BackgroundIntracranial abscess formation is an extremely rare and sporadically documented disease in South American Camelids (SACs). Herein we report the first case of otogenic brain abscess formation in this species.Case presentationA 4 years old female alpaca was presented to our veterinary hospital with a 6 month history of neurologic disorder symptoms, mainly head tilt to the right and emaciation. A comprehensive workup (ultrasound and computed tomography) revealed irreversible cranial nerve abnormalities, extensive lesions in the region of external, middle and internal right ear including destruction of bony structures (tympanic bulla, parts of temporal bone) and severe brain deformation caused by an intracranial abscess. The lesion was up to 6x7x4 cm and occupying almost 40% of the cranial cavity. No pathological findings were evident in other organs or structures. The late referral of the alpaca at this advanced stage of destructive disease precluded surgical intervention.ConclusionsThis case report describes the clinical signs, diagnostic procedures and pathological findings in an adult female alpaca suffering from cranial nerve abnormalities caused by a massive otogenic brain abscess. Camelids suffering from otitis may not present with clinical signs until the pathology is severe. The importance of considering intracranial abscess formation as differential diagnosis in SACs showing the merest hint of nerve deficits cannot be emphasized enough in order to diagnose such pathological processes at an early and treatable stage.

Neuropathological findings suggestive for a stroke in an alpaca (Vicugna pacos)

BackgroundThis case report describes a focal brain lesion in an alpaca (Vicugna pacos). Although this is a restricted study based on a single animal, neuropathological features are reported that are most likely attributed to a vascular event with either ischemic or hemorrhagic pathology. Concerning translational issues, these findings extend neurovascular unit concept to the alpacas’ brain and qualify a larger panel of stroke tissue markers for further exploration of ischemic or hemorrhagic consequences beyond the usually used small animal models in stroke research.Case presentationA brain lesion indicative of a stroke was diagnosed in a 3-year-old female alpaca as an incidental finding during a post mortem examination. The rostral portion of the right frontal lobe contained a 1.0 × 1.5 × 1.7 cm lesion that extended immediately to the overlying leptomeninges. Microscopically, it was composed of liquefactive necrosis with cholesterol crystal deposition and associated granulomatous inflammation as well as vascularized fibrous connective tissue rimmed by proliferated astrocytes. Multiple fluorescence labeling of the affected brain regions revealed strong microgliosis as shown by immunostaining of the ionized calcium binding adapter molecule 1 and astrogliosis as demonstrated by enhanced immunoreactivity for glial fibrillary acidic protein. In parallel, a drastic neuronal loss was detected by considerably diminished immunolabeling of neuronal nuclei. Concomitantly, up-regulated immunoreactivities for collagen IV and neurofilament light chains were found in the affected tissues, indicating vascular and cytoskeletal reactions.ConclusionsDriven by these neuropathological features, the incidental brain lesion found in this alpaca strongly suggests an ischemic or hemorrhagic etiology. However, since typical hallmarks became verifiable as previously described for other species affected by focal cerebral ischemia, the lesion is more likely related to an ischemic event. Nevertheless, as such cellular alterations might be difficult to distinguish from other brain lesions as for instance caused by inflammatory processes, adjuvant observations and species-related features need to be considered for etiological interpretations. Indeed, the lack of neurological deficits is likely attributed to the location of the lesion within the rostral aspect of the right frontal lobe of the alpacas’ brain. Further, fibroblast migration from the meninges likely caused the intralesional scar formation.

A novel pulmonary polyomavirus in alpacas (Vicugna pacos)

Viral metagenomic analysis detected a novel polyomavirus in a 6-month old female alpaca (Vicugna pacos) euthanized after a diagnosis of disseminated lymphosarcoma. The viral genome was fully sequenced, found to be similar to other polyomaviruses in gene architecture and provisionally named Alpaca polyomavirus or AlPyV. Viral nucleic acid was detected by PCR in venous blood, spleen, thymus, and lung. AlPyV phylogenetically clustered in the “Wuki” group of PyVs, which includes WU and KI polyomaviruses, commonly found in human respiratory samples. In an ISH analysis of 17 alpaca necropsies, 7 had detectable virus within the lung. In animals without pneumonia, probe hybridization was restricted to the nuclei of scattered individual bronchiolar epithelial cells. Three of the ISH positive alpacas had interstitial pneumonia of unknown origin, and in these animals there was viral nucleic acid detected in bronchiolar epithelium, type II pneumocytes, and alveolar macrophages. The pattern of AlPyV distribution is consistent with a persistent respiratory virus that has a possible role in respiratory disease.

Dystrophic mineralization of the arterial fibrovascular tissue associated with a vitamin D hypervitaminosis in an 8-year-old female Alpaca (Vicugna pacos).

BackgroundProphylactic Vitamin D supplementation is a common practice in Alpaca breeding in many regions around the world. An overdosage can lead to dystrophic mineralization of soft tissues. In this paper we illustrate a suspected case of hypervitaminosis D in an 8-year-old female Alpaca.Case presentationIn June 2015, the carcass of an 8-year-old female Alpaca (Vicugna pacos) was submitted to the diagnostic laboratory of the Istituto Zooprofilattico Sperimentale delle Venezie (IZSVe) for necropsy. The animal had undergone a spontaneous abortion with uterine prolapse and delivery of the placenta, and had died shortly thereafter. Death occurred due to internal haemorrhage related to dystrophic mineralization of the left renal artery with subsequent rupture and damage of the renal hilum. During the necropsy, histopathological and serum biochemical analyses were performed. After laboratory analyses and the history of mineral and vitamin supplementation reported by the breeder, a hypervitaminosis D was suspected to be the most probable cause of the dystrophic mineralization observed in the left renal artery.ConclusionsMost of the information regarding Llamas and Alpacas comes from the South American and Australian regions. It is therefore important to provide scientific information about these animals in other regions of the world in order to have a better and wider understanding of the nutritional and environmental conditions necessary for optimal breeding.

Bovine xenograft application for treatment of a metatarsal nonunion fracture in an alpaca (Vicugna pacos)

CASE HISTORY: A 15-year-old female huacaya alpaca (Vicugna pacos) was referred because of a non-weight-bearing lameness (4/4) in the left pelvic limb caused by a grade three open metatarsal fracture. The referring veterinarian treated the fracture with conservative management using bandages, but it progressively evolved to a non-union.CLINICAL FINDINGS AND DIAGNOSIS: Clinical examination revealed external wounds on the medial and lateral surfaces of the metatarsus. Radiographs confirmed an open, nonarticular, displaced, diaphyseal fracture of the left metatarsus.TREATMENT AND OUTCOME: Cancellous bone was sourced from bovine proximal and distal femur epiphyses, followed by a thermal shock procedure to achieve decellularisation, to produce a xenograft. Open reduction and internal fixation of the fracture using locking plates was performed. Alignment of the fracture fragments was corrected and the xenograft was placed at the debrided fracture site to stimulate and harness osteogenesis in situ. Clinical and radiographic follow-up was performed up to 40 weeks postoperatively. Clinical evaluations revealed that the alpaca gradually increased weight bearing following bandage removal 10 days after surgery. Serial radiographs showed correct alignment of the left metatarsus, progressive bone modelling and, complete bone union at 12 weeks. Ten months postoperatively the alpaca showed no signs of lameness and resumed normal activity.CLINICAL RELEVANCE: For management of a metatarsal non-union, a combination of bovine xenograft application and angular stable internal fixation progressed toward an excellent long-term recovery.