IntroductionThoracoscopic surgery is a widely accepted minimally invasive technique in veterinary medicine. However, its application in small dogs is limited by the narrow thoracic space, difficulty accessing midline structures, and the requirement for one-lung ventilation. To overcome these limitations, a single-incision subxiphoid approach with low-pressure CO2 insufflation may offer improved visualization and access, but objective, quantitative evidence supporting its feasibility remains insufficient.Materials and methodsEight canine cadavers (6–10 kg) underwent subxiphoid single-port thoracoscopy under mechanical ventilation with non-insufflation and 3 mmHg CO2 insufflation. Visualization quality was quantitatively evaluated using image analysis, and lung lobe accessibility was scored. The feasibility and safety of accessory lung lobectomy using a pretied ligature loop was assessed, including air leakage testing.ResultsCO2 insufflation at 3 mmHg group significantly enhanced thoracoscopic visualization compared to non-insufflation group, particularly by reducing visual obstruction from the left middle and right caudal lung lobes. All lung lobes were accessible through a single incision, though the accessory lung lobe was more difficult to approach (mean exploration score: 0.59). Accessory lung lobectomy using a pretied loop was successfully completed in all cadavers without evidence of air leakage, with an average procedure time of 921 s.DiscussionA single-incision subxiphoid thoracoscopic approach combined with low-pressure CO2 insufflation significantly improves visualization and instrument maneuverability in small-breed canine cadavers. This method also enables complete lung lobe exploration and allows safe and effective accessory lung lobectomy using a pretied ligature loop.

Abstract This case highlights an accessory lung lobe carcinoma with radiographic and computed tomography characteristics similar to mediastinal paraoesophageal abscessation. Initial radiographs suggested an increased soft tissue opaque structure within the caudal thorax. Thoracic computed tomography suggested the presence of a caudal mediastinal paraoesophageal abscess; however, an accessory lung lobe mass with adherence to surrounding structures was identified following a lateral thoracotomy. This patient recovered well from surgery, but ultimately continued to have clinical signs related to the diagnosed neoplasia, and was humanely euthanased approximately 8 weeks after surgery.

Abstract An 8‐year‐old, male, neutered border collie was presented with spontaneous pneumothorax. Computed tomography identified a large bulla in the distal right cranial lung lobe as well as accessory lung lobe consolidation. The patient underwent thoracotomy via median sternotomy, which identified a leak from the bulla; therefore, a partial right cranial and a complete accessory lung lobectomy were performed. Histological analysis of both lung lobes revealed mild endogenous lipid pneumonia, and no specific cause of the bulla was identified. The dog tested negative for Dirofilaria immitis; therefore, a diagnosis of mild, idiopathic endogenous lipid pneumonia was made. The patient suffered only a minor complication of skin incision dehiscence, which was treated conservatively with no recurrence of the pneumothorax at 9 months post‐operatively.

To describe a combined transdiaphragmatic and caudal median sternotomy (TDCM) approach to the accessory lung lobe and to compare its accessibility with intercostal thoracotomy (ICT) and median sternotomy (MS). Cadaveric study. Twelve canine cadavers. Cadavers underwent an accessory lung lobectomy using an articulating EndoGIA stapler via randomly assigned approach: ICT (n = 4), MS (n = 4) or TDCM (n = 4). The percentage of accessory lung tissue removed was measured in surface area and weight. Exposure was measured as area of cavitary or bicavitary exposure at maximal retraction, by tracing a line around the circumference of the exposed cavity using an imaging software. Staple line leak pressures were evaluated to 40 cmH2O. The average area of exposure was larger in the TDCM approach (TDCM = 193.5 cm2, MS = 106.5 cm2, ICT = 73.5 cm2); (p = .01). Two of four ICT staple lines leaked at 40 cmH2O or lower, and 1/4 MS resulted in iatrogenic damage to an adjacent lobe. There was no difference in the percentage of the lobe excised by weight or surface area between groups. The transdiaphragmatic and caudal median sternotomy approach provided greater exposure, although the percentage of the lobe excised and the surgical time did not differ between approaches. All three approaches allowed for adequate excision of the accessory lung lobe (ALL) with similar surgical times; however, the TDCM approach provided a greater area of exposure, which could increase accessibility to the ALL.

Abstract Recent studies have indicated that providing an effective probiotic to dams and their progeny allows the pigs to respond more favorably to viral challenges (Lerner et al., 2020; Bertram et al., 2022). Sixteen pregnant dams (parity 1 to 5) allotted by gestation pen were exposed to one of two treatments: Control (CON) where dams consumed a standard, non-probiotic containing, gestation and lactation diet or Bacillus (BAC) where dams consumed standard diets with a daily top dress applied to achieve 1.65 x 106 CFUs of Bacillus/gram of complete feed from 5 weeks before farrowing through lactation. Ninety-six nursery pigs were allotted (48 per treatment group) to the nursery portion of this study at weaning. The CON pigs selected for the nursery received non-probiotic containing feed and BAC pigs selected for the nursery received 1.10 x 106 CFUs Bacillus/gram of complete feed for the 3-wk nursery period of the study. Pigs were separated into 8 pens with 6 pigs per pen by treatment. Individual pig body weights and pen feed intakes were recorded on d 0, 7, 14, and 21. Following 14-d of feed acclimatization post-weaning, all pigs received an H1N2 Influenza viral challenge via intratracheal gavage (Haesebrouck et al., 1986). Clinical signs, including rectal temperatures, respiratory score, abdominal score, and demeanor score we collected daily beginning 1 d before challenge (d 13) through the end of the study. On d 21, following body weight collection, all pigs were euthanized, lungs were removed, and each of seven lung lobes (right and left cranial, right and left middle, accessory, and right and left caudal) were scored on percentage of lobes bearing gross (visible) lung lesions (Halbur et al., 1996). Pigs in the BAC group had better F:G ratios during the pre-challenge (1.177 vs. 1.309, P < 0.01), post-challenge (1.418 vs. 1.633, P < 0.01), and entire growth (1.287 vs. 1.464, P < 0.001) periods, compared with those of the CON group. The percentage of pigs in the BAC group with gross lung lesions in the left and right cranial, accessory, and left and right caudal lung lobes was less than those of the CON group (Table 1). Additionally, total lung lobes with lesions per pig (4.1 vs. 5.3, P < 0.001) were lower in pigs in the BAC group. These data indicate that application of a Bacillus-based probiotic (in this case BioPlus 2B) to sows and subsequently their weaned progeny is associated with better feed efficiency and fewer lung lesions following a challenge with H1N2 Influenza.

To describe (1) the surgical anatomy of the accessory lung lobe (ALL) including vasculature and pulmonary ligamentous attachments and (2) lobectomy through a right thoracotomy and median sternotomy. Cadaveric anatomical study. Nine adult canine cadavers, free of disease affecting the thoracic cavity and lung parenchyma. Median sternotomy and right and left lateral thoracotomies were performed to describe and image relevant variations in anatomy using accompanying photographs and thorough voice notes. Consideration for ALL removal via right thoracotomy at the fifth through seventh intercostal spaces and median sternotomy were documented and compared. The median weight of the cadavers was 20.85 kg (6.9-45.5 kg). Variation in the configuration of venous drainage of the ALL was identified. The lateral vein varied in its location and was also observed to combine with the medial vein in one cadaver. The pulmonary ligament attached to the ALL in a caudally pointing apex on the dorsal process of the lobe. Medial and lateral extensions of the ALL parenchyma were found. The ALL was most easily accessed by a right lateral thoracotomy at the sixth intercostal space. Although not optimal, removal of this lung lobe via median sternotomy was feasible. Significant variations were found in the blood supply to the ALL. A right lateral thoracotomy at the sixth intercostal space was preferred for a surgical approach to the ALL. Surgeons should be aware of several anatomical particularities including the venous drainage, ligamentous attachments, and parenchymal extensions of the ALL.

A 5-year-old castrated male domestic shorthair cat was referred for further investigation of pulmonary nodules incidentally detected on thoracic radiographs. Thoracic radiographs identified ill-defined soft tissue opacity nodules with small faint mineral opacity. Thoracic computed tomography (CT) revealed that bronchial dilation and bronchial wall thickening in bilateral cranial and accessory lung lobes. Round to ellipsoid mineralized concretions were found embedded in the intrabronchial soft tissue attenuation material. Based on radiography, CT, and cytology, the patient was tentatively diagnosed as having broncholithiasis with chronic bronchitis. This report described the CT diagnosis of broncholithiasis, which has been rarely reported in a cat.

Abstract A 4‐year‐old female neutered Welsh Springer Spaniel was presented with pneumothorax secondary to a migrating foreign body in the right caudal lung lobe. Within 24 hours following thoracic exploration and hilar lung lobectomy, the patient deteriorated. CT was consistent with lobar torsion. A second median sternotomy identified concurrent right cranial and middle lung lobe torsion. Hilar lobectomy of the affected lobes was performed. To prevent lobar torsion of the remaining lobe, a preventative accessory lobe pneumopexy was performed, potentially averting an additional surgical procedure and reducing total lung capacity to less than the reported minimum critical mass compatible with survival. No complications following accessory lung lobe pneumopexy were encountered in this single case. Although post‐lobectomy lung lobe torsion appears to be rare in dogs, clinicians should be aware of this potentially life‐threatening complication. This case report documents the first description of pneumopexy as a preventative procedure in a dog.

Abstract A seven‐year‐old female Chinchilla cat and a 13‐year‐old male Cocker Spaniel were presented to Dick White Referrals for respiratory difficulties and cough, respectively. Based on radiographic and CT findings, including the midline location of the lesion and its mass effect on mediastinal structures, a caudodorsal mediastinal mass was considered more likely than a pulmonary origin in both cases. However, further investigations in the form of thoracic ultrasound and ultrasound‐guided fine needle aspirates in the first case and histopathology in the second, revealed the presence of an accessory lobe pulmonary carcinoma in both cases. Retrospective review of these cases allowed identification of CT features that can be used to distinguish mediastinal and accessory lung lobe masses in future cases, including absence of part or all of the accessory lobe and its lobar bronchus, presence of gas in the lesion and the shape of the lesion mimicking a lung lobe.

CRISPR/Cas9-mediated gene editing often generates founder generation (F0) mice that exhibit somatic mosaicism in the targeted gene(s). It has been known that Fibroblast growth factor 10 (Fgf10)-null mice exhibit limbless and lungless phenotypes, while intermediate limb phenotypes (variable defective limbs) are observed in the Fgf10-CRISPR F0 mice. However, how the lung phenotype in the Fgf10-mosaic mutants is related to the limb phenotype and genotype has not been investigated. In this study, we examined variable lung phenotypes in the Fgf10-targeted F0 mice to determine if the lung phenotype was correlated with percentage of functional Fgf10 genotypes. Firstly, according to a previous report, Fgf10-CRISPR F0 embryos on embryonic day 16.5 (E16.5) were classified into three types: type I, no limb; type II, limb defect; and type III, normal limbs. Cartilage and bone staining showed that limb truncations were observed in the girdle, (type I), stylopodial, or zeugopodial region (type II). Deep sequencing of the Fgf10-mutant genomes revealed that the mean proportion of codons that encode putative functional FGF10 was 8.3 ± 6.2% in type I, 25.3 ± 2.7% in type II, and 54.3 ± 9.5% in type III (mean ± standard error of the mean) mutants at E16.5. Histological studies showed that almost all lung lobes were absent in type I embryos. The accessory lung lobe was often absent in type II embryos with other lobes dysplastic. All lung lobes formed in type III embryos. The number of terminal tubules was significantly lower in type I and II embryos, but unchanged in type III embryos. To identify alveolar type 2 epithelial (AECII) cells, known to be reduced in the Fgf10-heterozygous mutant, immunostaining using anti-surfactant protein C (SPC) antibody was performed: In the E18.5 lungs, the number of AECII was correlated to the percentage of functional Fgf10 genotypes. These data suggest the Fgf10 gene dose-related loss of the accessory lobe and decrease in the number of alveolar type 2 epithelial cells in mouse lung. Since dysfunction of AECII cells has been implicated in the pathogenesis of parenchymal lung diseases, the Fgf10-CRISPR F0 mouse would present an ideal experimental system to explore it.

Purpose To assess the feasibility of thoracoscopic transdiaphragmatic approach for biopsy of all lung lobes and to determine the optimal intercostal space (ICS) for biopsy of each lung lobe.Methods Ten rabbits were positioned in dorsal recumbency. Total thoracoscopy lung biopsy was made combined transdiaphragmatic approach and right ICS approaches. A camera port was made in the transdiaphragmatic approach and the instrument port was made of ICS 7 and ICS 9. A pre tied loop ligature was placed to performed a caudal lung lobe biopsy and to simulate biopsies of the others lung lobes.Results Biopsy of the cranial aspect of the right caudal lung lobe was performed at ICS 9. Simulated biopsy of the accessory lung lobe was performed at ICS 9. Simulated lung biopsy of the right cranial and middle lung lobes was performed at ICS 7. The caudal and dorsal aspect of the right caudal lung lobe was not visualized by telescope at transdiaphragmatic approach, and biopsy was not performed.Conclusions Thoracoscopic transdiaphragmatic approach for lung lobes biopsies was a feasible technique, except for the caudal aspect of the right caudal lung lobe. An ideal intercostal port for biopsy of each right lung lobe was determined.

To determine the optimal intercostal space (ICS) for thoracoscopic-assisted pulmonary surgery for lung lobectomy in cats. 8 cat cadavers. Cadavers were placed in lateral recumbency. A 5-cm minithoracotomy incision was made in the middle third of ICS 4 through 7 on the left side and 4 through 8 on the right side, and a wound retractor device was placed. A camera port was made in the middle third of ICS 9. Each lung lobe was sequentially exteriorized at each respective ICS. A thoracoabdominal stapler was placed to simulate a lung lobectomy, and distance from the stapler anvil to the hilus was measured. For the left cranial lung lobe, there was no significant difference in median distance from the stapler anvil to the pulmonary hilus for ICS 4 through 6. Simulated lobectomy of the left caudal lung lobe performed at ICS 5 and 6 resulted in a significantly shorter distance, compared with lobectomy performed at ICS 4 and 7. Simulated lobectomy of the right cranial and right middle lung lobes performed at ICS 4 and 5 resulted in a significantly shorter distance, compared with lobectomy performed at ICS 7. Simulated lobectomy of the accessory and right caudal lung lobes at ICS 5 and 6 resulted in a significantly shorter distance than for lobectomy performed at ICS 8. An optimal ICS for a minithoracotomy incision was determined for thoracoscopic-assisted lung lobectomy in cats.

The aim of the study was to provide a detailed anatomical study of the feline bronchial and vascular structures by using CT angiography (CTA). Adult cats with no respiratory clinical signs were enrolled in a CTA protocol to provide an anatomical study of the thorax. The dimensions, number of branches and branching pattern (monopodial vs dichotomic) of both bronchial and pulmonary vascular structures were evaluated under positive inspiration apnoea. A linear generalised estimating equations analysis (Spearman's rho) was used to identify statistical correlation between tracheal diameter, age and body weight of the cats. Fourteen cats met the inclusion criteria. The pulmonary arteries had larger diameters than the pulmonary veins, and the pulmonary veins had larger diameters than the bronchial structures. A higher number of segmental bronchial and pulmonary vascular branches was observed in the left caudal lung lobe than in the other lobes. The monopodial branching pattern of both bronchial and pulmonary vascular structures was predominant in all cats of our study (100%) in cranial, caudal and right middle lung lobes, while a dichotomic branching pattern of the bronchial and pulmonary vascular structures of the accessory lung lobe was seen in 13 cats (93%). Thirteen cats (93%) had three pulmonary vein ostia, and one cat (7%) also presented with an additional left intermediate pulmonary vein ostium. Variation in the number of segmental pulmonary vein branches was noted in the right caudal lung lobe. There was no statistical correlation between tracheal diameter, age and weight. Architecture of the feline bronchovascularr structures belongs to a mixed type of monopodial and dichotomic branching pattern. In cats, the pulmonary venous drainage system predominately presents three pulmonary vein ostia. Variations in the type of formation and the number of branches of the pulmonary venous drainage system were noted.

To determine the optimal intercostal space (ICS) to perform thoracoscopic-assisted lung lobectomy. Cadaveric study. Six mature, medium-sized canine cadavers. Cadavers were placed in right or left lateral recumbency. A 15-mm thoracoscopic cannula was inserted in the middle third of the 9th or 10th ICS. A wound retraction device was placed into a 7-cm minithoracotomy incision created in the middle third of the 4th-7th ICS on the left side and the 4th-8th ICS on the right side. The pulmonary ligaments were sectioned by using a combined intracorporeal and extracorporeal technique. Each lung lobe was sequentially withdrawn from the wound retraction device at the respective ICS and side. A thoracoabdominal stapler was positioned to simulate lung lobectomy, and the distance from the stapler anvil to the hilus was measured. Simulated thoracoscopic-assisted lung lobectomy performed at left or right ICS 4 and 5, compared with other ICS evaluated, resulted in a significantly shorter median distance from the stapler anvil to the pulmonary hilus of the left cranial and caudal lung lobes and right cranial and middle lung lobes, respectively (all P < .05). Lobectomy at right ICS 5 or 6 resulted in a significantly shorter median distance from the stapler anvil to the pulmonary hilus of the right caudal and accessory lung lobes, respectively (both P < .05). These data may inform minithoracotomy positioning to optimize tumor margin excision during thoracoscopic-assisted lung lobectomy for treatment of pulmonary neoplasia in dogs. Complete lung lobectomy is possible by using the described thoracoscopic-assisted technique in normal, cadaveric lungs.

OBJECTIVE To evaluate changes in behavior and surfactant protein (SP) A and D concentrations in serum and bronchoalveolar lavage fluid (BALF) samples of calves experimentally infected with Mannheimia haemolytica. ANIMALS Twelve 4- to 5-month-old Holstein steers. PROCEDURES Calves were divided into 2 treatment groups and instrumented with a data logger to collect behavioral data. After 10 days of acclimation, calves were experimentally inoculated with 3 × 109 CFUs to 5 × 109 CFUs of M haemolytica suspended in approximately 5 mL of PBS solution (infected calves; n = 6) or 5 mL of PBS solution without M haemolytica (control calves; 6) through a catheter into the right accessory lung lobe. Calves were clinically evaluated twice daily for 7 days after inoculation. Blood and BALF samples were collected from all calves at predetermined times for determination of serum and BALF SP-A and SP-D concentrations. Serum and BALF concentrations of SP-A and SP-D and behavioral data were evaluated over time and between treatment groups. RESULTS Compared with control calves, infected calves spent more time lying in general and more time lying on the right side during the 24 hours and 6 days after inoculation, respectively. Mean rectal temperature for infected calves (41.3°C) was significantly greater than that for control calves (39.2°C) 12 hours after inoculation. Mean respiratory rate for infected calves (52.5 breaths/min) was significantly greater than that for control calves (45.4 breaths/min) throughout the observation period. CONCLUSIONS AND CLINICAL RELEVANCE Results indicated continuous behavioral monitoring may improve detection of calves with respiratory tract disease.

Correlative analysis requires examination of a specimen from macro to nano scale as well as applicability of analytical methods ranging from morphological to molecular. Accomplishing this with one and the same sample is laborious at best, due to deformation and biodegradation during measurements or intermediary preparation steps. Furthermore, data alignment using differing imaging techniques turns out to be a complex task, which considerably complicates the interconnection of results. We present correlative imaging of the accessory rat lung lobe by combining a modified Scanning Laser Optical Tomography (SLOT) setup with a specially developed sample preparation method (CRISTAL). CRISTAL is a resin-based embedding method that optically clears the specimen while allowing sectioning and preventing degradation. We applied and correlated SLOT with Multi Photon Microscopy, histological and immunofluorescence analysis as well as Transmission Electron Microscopy, all in the same sample. Thus, combining CRISTAL with SLOT enables the correlative utilization of a vast variety of imaging techniques.

A 6 yr old male Yorkshire terrier was presented for an ~6 yr history of progressive cough and dyspnea. Thoracic radiographs revealed a 6 cm diameter mass within the right caudal thorax. Thoracic ultrasound identified an intrathoracic mass ultrasonographically consistent with liver tissue and a chronic diaphragmatic hernia was suspected. Exploratory laparotomy was performed, but no evidence of a diaphragmatic hernia was identified. Thoracic exploration identified abnormal lung parenchyma. The accessory lung lobe was removed using a stapling devise near its base. The consolidated mass had the gross appearance of liver and was histologically identified as ectopic hepatic tissue. Ectopic hepatic tissue, unlike ectopic splenic and pancreatic tissue, is rare and generally has a subdiaphragmatic distribution. This solitary case report demonstrates that ectopic intrathoracic hepatic tissue should be considered a differential diagnosis for a caudal mediastinal mass.

To describe the demographics, clinical characteristics, diagnostic findings, underlying etiologies, treatment, and outcome associated with secondary spontaneous pneumothorax (SSP) in cats; and to identify clinical feature differences among cats with asthma associated secondary spontaneous pneumothorax (AASSP) versus nonasthma-associated secondary spontaneous pneumothorax (NAASSP). Retrospective case series. University teaching hospital. Sixteen client-owned cats with secondary spontaneous pneumothorax. None. Domestic short hair was the predominant breed in this study (n = 15). The median age was 8 years old (range: 7 weeks to 17 years) with no sex predilection. Fourteen cats were affected by multi-lobar pulmonary pathology of infectious, inflammatory, or neoplastic causes. Asthma was the most common cause of spontaneous pneumothorax (25%). Ten of 12 treated cats survived the initial episode of spontaneous pneumothorax to discharge with medical management, including all 4 cats with AASSP. Reoccurrence was documented in 4 cats. Pulmonary lobectomy was curative for 1 cat with congenital accessory lung lobe emphysema. No difference in clinical presentation was identified between cats with AASSP and cats with NAASSP. Feline SSP is frequently associated with extensive pulmonary pathology. Supportive medical management is most appropriate, except in rare cases with focal congenital abnormalities that may benefit from surgical intervention. AASSP appears to carry a good prognosis for short-term outcome (survival to discharge). Clinical assessment, imaging, and invasive diagnostics were required to differentiate between AASSP and NAASSP.

Aelurostrongylus abstrusus infection is common in endemic areas and may cause severe respiratory clinical signs. Computed tomography (CT) is an important tool to diagnose pulmonary disease, because it allows detection of small lesions and discrimination of superimposed structures. The purpose of this study was to characterize by CT and angiographic CT the pulmonary lesions in six cats before, and 48 and 81 days after inoculation with 100 or 800 A. abstrusus infective larvae. Histological examination of the accessory lung lobe was performed to determine the microscopic, pathomorphologic correlate of the CT findings. The predominant CT lesion consisted of multiple nodules of varying size distributed throughout the lungs, severity depending on infectious dose. The histological correlate of the nodular lesions was multifocal dense granulomatous to mixed inflammatory cell infiltrates, including eosinophils distributed in the parenchyma and obliterating the alveoli. Marked, multifocal, dose-dependent thickening of the bronchi and adjacent interstitial changes blurred the margins of the outer serosal surface of the bronchi and vessels. Histologically, this was due to peribronchial mixed cell inflammation. During the course of infection some of the nodular and peribronchial changes were replaced by areas of ground-glass opacity. In addition to providing detailed depiction of pulmonary lesions resulting from an infectious cause and clearly defining lesions with respect to time and severity of infection, CT allowed quantitative assessment of bronchial thickness and lymph node size during the course of disease. Findings indicated that CT characteristics of this disease are consistent with pathologic findings.

To characterize and quantitatively assess the typical pulmonary anatomy of healthy adult alpacas with multidetector row CT. 10 clinically normal adult female alpacas. CT examination of the thorax was performed before and after IV administration of iodinated contrast medium in sedated alpacas in sternal recumbency. Measurements of the trachea, bronchi and related blood vessels, and selected vertebrae as well as the extent and density of lung parenchyma were performed with a Digital Imaging and Communications in Medicine (DICOM) viewer. Morphometric and quantitative data were summarized. Separation of individual lung lobes could not be identified, except for the accessory lung lobe. In all alpacas, both lungs extended farther caudally at the medial aspect than at the lateral aspect. The right lung extended farther in both cranial and caudal directions than did the left lung. The branching pattern of the bronchial tree varied only slightly among alpacas and consisted of 1 cranial bronchus and 3 caudal bronchi bilaterally, with a right accessory bronchus. Luminal diameters of first-generation bronchi ranged from 3 to 9 mm. Mean ± SD parenchymal lung density was -869 ± 40 Hounsfield units (HU) before contrast injection and -825 ± 51 HU after contrast injection. Mean difference in diameter between bronchi and associated arteries or veins was 0.8 ± 0.9 mm. Knowledge of the typical anatomy of the lungs and bronchial tree in healthy alpacas as determined via CT will aid veterinarians in clinical assessment and bronchoscopic evaluation of alpacas.