Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 40
Filtrar
1.
Anim Cogn ; 27(1): 40, 2024 May 24.
Artículo en Inglés | MEDLINE | ID: mdl-38789595

RESUMEN

Optical illusions have long been used in behavioural studies to investigate the perceptual mechanisms underlying vision in animals. So far, three studies have focused on ungulates, providing evidence that they may be susceptible to some optical illusions, in a way similar to humans. Here, we used two food-choice tasks to study susceptibility to the Müller-Lyer and Delboeuf illusions in 17 captive individuals belonging to four ungulate species (Lama guanicoe, Lama glama, Ovis aries, Capra hircus). At the group level, there was a significant preference for the longer/larger food over the shorter/smaller one in control trials. Additionally, the whole group significantly preferred the food stick between two inward arrowheads over an identical one between two outward arrowheads in experimental trials of the Müller-Lyer task, and also preferred the food on the smaller circle over an identical one on the larger circle in the experimental trials of the Delboeuf task. Group-level analyses further showed no significant differences across species, although at the individual level we found significant variation in performance. Our findings suggest that, in line with our predictions, ungulates are overall susceptible to the Müller-Lyer and the Delboeuf illusions, and indicate that the perceptual mechanisms underlying size estimation in artiodactyls might be similar to those of other species, including humans.


Asunto(s)
Camélidos del Nuevo Mundo , Ilusiones Ópticas , Animales , Camélidos del Nuevo Mundo/psicología , Femenino , Masculino , Cabras/psicología , Percepción del Tamaño , Ovinos
2.
Reprod Biol Endocrinol ; 16(1): 83, 2018 Aug 31.
Artículo en Inglés | MEDLINE | ID: mdl-30170607

RESUMEN

BACKGROUND: A molecule identical to nerve growth factor, with ovulation-inducing properties has been discovered in the seminal plasma of South American camelids (ovulation-inducing factor/nerve growth factor; OIF/NGF). We hypothesize that the ovulatory effect of OIF/NGF is initiated at the level of the hypothalamus, presumably by GnRH neurons. The objective of the present study was to determine the structural relationship between GnRH neurons and neurons expressing high- and low-affinity receptors for NGF (i.e., TrkA and p75, respectively) in the hypothalamus. METHODS: Mature llamas (n = 4) were euthanized and their hypothalamic tissue was fixed, sectioned, and processed for immunohistochemistry on free-floating sections. Ten equidistant sections per brain were double stained for immunofluorescence detection of TrkA and GnRH, or p75 and GnRH. RESULTS: Cells immunoreactive to TrkA were detected in most hypothalamic areas, but the majority of cells were detected in the diagonal band of Broca (part of the ventral forebrain) and the supraoptic nuclei and periventricular area. The number of cells immunoreactive to p75 was highest in the diagonal band of Broca and lateral preoptic areas and least in more caudal areas of the hypothalamus (p < 0.05) in a pattern similar to that of TrkA. A low proportion of GnRH neurons were immunoreactive to TrkA (2.5% of total GnRH cells), and no co-localization between GnRH and p75 was detected. GnRH neuron fibers were detected only occasionally in proximity to TrkA immunopositive neurons. CONCLUSIONS: Results do not support the hypothesis that the effect of OIF/NGF is driven by a direct interaction with GnRH neurons, but rather provide rationale for the hypothesis that interneurons exist in the hypothalamus that mediate OIF/NGF-induced ovulation.


Asunto(s)
Camélidos del Nuevo Mundo/fisiología , Hormona Liberadora de Gonadotropina/farmacología , Hipotálamo/efectos de los fármacos , Ovulación/fisiología , Animales , Inmunohistoquímica , Técnicas In Vitro , Ovulación/efectos de los fármacos , Receptor trkA/metabolismo , Receptores de Factor de Crecimiento Nervioso/metabolismo
3.
Gen Comp Endocrinol ; 263: 43-50, 2018 07 01.
Artículo en Inglés | MEDLINE | ID: mdl-29656045

RESUMEN

Gonadotropin-releasing hormone (GnRH) is a decapeptide involved in the regulation of reproduction in all mammals, but the distribution of GnRH neurons within the brain varies widely among species. The objective of the present study was to characterize the number and distribution of GnRH neurons in the hypothalamus and preoptic area of llamas, an induced ovulator. The brains of female llamas (n = 4) were fixed, frozen and sectioned serially every 50 µm in the transverse (coronal) plane. Every 10th section was stained for immunohistochemical detection of GnRH-positive neuron cell bodies and fibers by incubation with 3,3'-diaminobenzidine. The number of counted immunoreactive cells ranged from 222 to 250 (≈241 ±â€¯13 cells in the preoptic area and hypothalamus per animal) and were localized in the medio-basal hypothalamus (44.3%), anterior hypothalamus (27%), preoptic area (14.9%), diagonal band of Broca/medial septum (13.4%), and mammillary area (0.5%). The immunoreactive cells were not localized in specific hypothalamic nuclei, but rather appeared to be distributed diffusely. The highest concentration of immunoreactive neuron fibers was in the median eminence (P < 0.05), but fibers were identified in most of the areas analyzed, including the neurohypophysis. The GnRH neurons within the hypothalamus displayed monopolar (33%), bipolar (39%), and multipolar (28%) morphologies. The bipolar type was most common in the medio-basal region (40%; P < 0.05). We conclude that GnRH neurons and fibers form a network within the anterior and medio-basal hypothalamus of llamas, suggesting the central location of mechanisms controlling reproductive processes in llamas (i.e., induced ovulation).


Asunto(s)
Camélidos del Nuevo Mundo , Hormona Liberadora de Gonadotropina/metabolismo , Hipotálamo , Neuronas/citología , Neuronas/metabolismo , Inducción de la Ovulación , Animales , Encéfalo/citología , Encéfalo/metabolismo , Camélidos del Nuevo Mundo/metabolismo , Recuento de Células , Forma de la Célula , Femenino , Fase Folicular/metabolismo , Hipotálamo/citología , Hipotálamo/metabolismo , Eminencia Media/citología , Eminencia Media/metabolismo , Inducción de la Ovulación/veterinaria , Área Preóptica/citología , Área Preóptica/metabolismo , Distribución Tisular
4.
Parasitol Res ; 117(7): 1999-2013, 2018 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-29804192

RESUMEN

Camelids (llamas, alpacas, vicuñas, guanacos) are important for the economy of South America and Eimeria infections are important as cause of mortality in camelids. Of the five most prevalent species of Eimeria in South American camelids, Eimeria macusaniensis, Eimeria lamae, Eimeria alpacae, Eimeria punoensis, and Eimeria ivitaensis, E. macusaniensis is considered the most pathogenic. There is considerable confusion concerning the endogenous developmental stages of Eimeria spp. in camelids. Many papers on camelid coccidiosis were published in local Peruvian journals, not easily accessible to wider audience. The objective of the present paper is to summarize information on history, validity of Eimeria species, life cycle, pathogenicity, prevalence, epidemiology, diagnosis, and control of coccidiosis in camelids.


Asunto(s)
Camélidos del Nuevo Mundo/parasitología , Coccidiosis , Eimeria/patogenicidad , Animales , Coccidiosis/diagnóstico , Coccidiosis/epidemiología , Coccidiosis/terapia , Coccidiosis/veterinaria , Heces/parasitología , Prevalencia , América del Sur/epidemiología
5.
J Vet Pharmacol Ther ; 41(6): 861-870, 2018 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-30020535

RESUMEN

In llama crias (tekes), Escherichia coli and Staphylococcus aureus are major pathogens, and marbofloxacin could be a suitable choice. The objectives of this study were (a) to evaluate the serum pharmacokinetics of marbofloxacin (5 mg/kg) after intravenous administration in tekes and simulate a multidose regimen; (b) to emulate pharmacokinetic profiles after single dose and steady-state conditions by Monte Carlo simulation (c) to determine the MIC of regional strains of Escherichia coli and Staphylococcus aureus; (d) to perform a PK/PD analysis by Monte Carlo simulation. Pharmacokinetics of marbofloxacin was evaluated in six animals at 3, 10, 24, 50, and 80 days after birth. Marbofloxacin were determined by HPLC. A steady-state multi-dose simulation was carried out, and concentration-time profiles were generated by Monte Carlo simulation. MIC of marbofloxacin against regional E. coli and S. aureus strains were also determined. Finally, a PK/PD analysis was conducted by Monte Carlo simulation. After pharmacokinetic analysis, clearance showed a trend to increase (0.14 and 0.18 L kg-1  hr-1 ), and AUC (36.74 and 15.21 µg hr-1  ml-1 ) and Vss (3.06 and 3.37 L/kg) trended to decrease at 3 and 80 days-old, respectively, showing accumulation ~50% in animals with 3 days. All strains tested of E. coli (MIC90  = 0.06 µg/ml) and S. aureus (MIC90  = 0.25 µg/ml) were susceptible to marbofloxacin. PK/PD analysis suggests that the therapeutic regimen of marbofloxacin could be effective for infections caused by E. coli strains in animals between 3 and 80 days, with a CFR for Cmax /MIC > 10 of 100% and for AUC24 /MIC > 125 of 99.99%; and for infections produced by S. aureus in animals between 3 and 24 days old, with a CFR for Cmax /MIC > 10 of 93.08% and for AUC24 /MIC > 60 of 97.01%, but a higher dose should be used in older animals, because PK/PD endpoints were not met.


Asunto(s)
Antibacterianos/farmacocinética , Camélidos del Nuevo Mundo/sangre , Fluoroquinolonas/farmacocinética , Animales , Antibacterianos/administración & dosificación , Área Bajo la Curva , Simulación por Computador , Relación Dosis-Respuesta a Droga , Esquema de Medicación , Escherichia coli/efectos de los fármacos , Inyecciones Intravenosas , Pruebas de Sensibilidad Microbiana , Modelos Biológicos , Método de Montecarlo , Staphylococcus aureus/efectos de los fármacos
6.
Reprod Domest Anim ; 52(4): 625-631, 2017 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-28332278

RESUMEN

The aim of this study was to compare the effect of the intramuscular administration of 50 µg of gonadorelin acetate versus natural mating, intrauterine infusion (i.u.) of a physiological relevant dose of either raw llama seminal plasma (SP) or purified beta-nerve growth factor from seminal origin (spß-NGF) on ovulation rate and corpus luteum (CL) development and function in llamas. Females with a follicle (≥8 mm) were assigned to groups: (i) i.m. administration of 50 µg of gonadorelin acetate (GnRH; positive control; n = 4); (ii) single mating (mating; n = 6); (iii) i.u. infusion of 4 ml of llama SP (SP; n = 4); or (iv) i.u. infusion of 10 mg of spß-NGF contained in 4 ml of PBS (phosphate-buffered saline) (spß-NGF; n = 6). Ovaries were examined by power Doppler ultrasonography at 0, 1, 3, 6, 12 and 24 hr after treatment to determine preovulatory follicle vascularization area (VA), and additionally every 12 hr until Day 2 (Day of treatment = Day 0) to determine ovulation. Afterwards, ovaries were examined every other day until Day 8 to evaluate CL diameter and VA. Blood samples were collected on Days 0, 2, 4, 6 and 8 to determine plasma progesterone (P4) concentration. Ovulation rate did not differ (p = .7) among groups, but treatment affected (p < .0001) preovulatory follicle VA. Neither treatment administration nor treatment by time interaction affected (p ≥ .4) CL diameter, VA and plasma P4 concentration. Mating tended (p = .08) to increase CL VA when compared to the seminal plasma group by Day 8. Intrauterine administration of seminal plasma or spß-NGF does not increase CL size and function when compared to i.m. GnRH treatment, suggesting that the administration route of spß-NGF influences its luteotrophic effect in llamas.


Asunto(s)
Camélidos del Nuevo Mundo/fisiología , Copulación/fisiología , Cuerpo Lúteo/efectos de los fármacos , Hormona Liberadora de Gonadotropina/administración & dosificación , Factor de Crecimiento Nervioso/administración & dosificación , Animales , Vías de Administración de Medicamentos/veterinaria , Femenino , Hormona Luteinizante/sangre , Masculino , Ovario/efectos de los fármacos , Ovulación/efectos de los fármacos , Progesterona/sangre , Semen , Ultrasonografía
7.
Arch Anim Nutr ; 68(3): 171-85, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-24870266

RESUMEN

This study aimed to test whether the digestive and metabolic characteristics of pseudo ruminants provide superior ability to utilise low-quality diets compared to true ruminants. A total of 18 mature, non-pregnant, non-lactating female animals, including six llamas (Lama glama), six Danish Landrace goats and six Shropshire sheep, were used in a crossover design study. The experiment lasted for two periods of three weeks. Half of the animals were fed either high-quality grass hay (HP) or low-quality grass seed straw (LP) during each period. Animals were placed in metabolic cages during the last 5 d, and gaseous exchange was measured by open-circuit indirect calorimetry for 22 h. Metabolisable energy for maintenance (MEm) and fasting energy expenditure (FEExp) were estimated by regression approach. Dry matter (DM) intake per kg(0.75) was substantially reduced in llamas and sheep, but not in goats, on the LP compared to HP diet. Llamas had lower daily energy expenditure (324 kJ · kg(-0.75)) than sheep (416 kJ · kg(-0.75)) and goats (404 kJ · kg(-0.75)) on the LP diet. Llamas in comparison with sheep and goats had lower methane emission (0.83 vs 1.34 and 1.24 l · d(-1) · kg(-0.75), p < 0.05), lower MEm (328 vs 438 and 394 kJ · d(-1) · kg(-0.75), p < 0.05) and lower FEExp (246 vs 333 and 414 kJ · d(-1) · kg(-0.75), p < 0.05), respectively. In conclusion, llamas had lower basal metabolic rate and hence maintenance requirements for energy.


Asunto(s)
Alimentación Animal/análisis , Camélidos del Nuevo Mundo/fisiología , Metabolismo Energético/fisiología , Cabras/fisiología , Metano/metabolismo , Ovinos/fisiología , Alimentación Animal/normas , Fenómenos Fisiológicos Nutricionales de los Animales , Animales , Estudios Cruzados , Dieta/veterinaria , Femenino , Nitrógeno/metabolismo , Poaceae
8.
Rev Argent Microbiol ; 46(1): 53-7, 2014.
Artículo en Español | MEDLINE | ID: mdl-24721276

RESUMEN

Llama population from Argentina is mainly concentrated in the Andean Puna, Jujuy. Llamas represent an important economic resource for the Andean communities. The aim of this study was to investigate the prevalence of antibodies against viral antigens associated to viral diseases of economic impact (neonatal diarrhea, reproductive and respiratory syndromes). A total of 349 serum samples from adult llamas were analyzed. The obtained antibody prevalence was 100 % for Rotavirus A and 70 % for Bovine parainfluenza virus 3. In contrast, no reactors were detected to Bovine herpesvirus 1, Bovine viral diarrhea virus 1, Human influenza A virus (H1N1) and Equine influenza virus (H3N8). These results confirm the wide circulation of rotavirus and parainfluenza virus in Argentinean llamas and suggest that susceptibility to infection with bovine herpesvirus, pestivirus and influenza A viruses is low. This serologic survey provides novel information regarding the epidemiology of viral diseases affecting llamas from the Argentinean Andean Puna.


Asunto(s)
Anticuerpos Antivirales/sangre , Camélidos del Nuevo Mundo/virología , Reservorios de Enfermedades/virología , Virosis/veterinaria , Animales , Animales Domésticos/virología , Argentina/epidemiología , Camélidos del Nuevo Mundo/sangre , Camélidos del Nuevo Mundo/inmunología , Virus de la Diarrea Viral Bovina/inmunología , Herpesvirus Bovino 1/inmunología , Humanos , Subtipo H1N1 del Virus de la Influenza A/inmunología , Subtipo H3N8 del Virus de la Influenza A/inmunología , Virus de la Parainfluenza 3 Bovina/inmunología , Pestivirus/inmunología , Salud Pública , Rotavirus/inmunología , Estudios Seroepidemiológicos , Virosis/epidemiología , Virosis/inmunología
9.
J Vet Diagn Invest ; : 10406387241258313, 2024 Jun 05.
Artículo en Inglés | MEDLINE | ID: mdl-38835270

RESUMEN

A 14-y-old intact female llama (Lama glama) was presented for evaluation of a right maxillary swelling of 3-mo duration. Clinically, the animal had mild nasal discharge, abnormal retropulsion of the right eye, and moderate gingival disease. An incisional biopsy of the maxillary mass revealed pleomorphic and mitotically active neoplastic spindle-to-stellate cells organized in haphazard lacunae embedded in abundant chondroid matrix. Given the poor prognosis, euthanasia was elected. Postmortem examination and sectioning of the head exposed a large solid, white, firm mass that vastly expanded the right infraorbital region, extending to the maxilla, effacing the right nasal conchae and ipsilateral zygomatic bone. Collectively, postmortem dissection, cytology, and histopathology of the primary mass supported a diagnosis of sinonasal chondrosarcoma. To our knowledge, this entity had not been reported previously in this species and should be considered a differential for facial deformities in New World camelids.

10.
J Am Vet Med Assoc ; 262(7): 1-6, 2024 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-38640950

RESUMEN

OBJECTIVE: To examine the prevalence of nasolacrimal duct (NLD) obstruction in hospital populations and assess signalment, diagnostics, and clinical approaches for alpacas and llamas diagnosed with NLD atresia or obstruction. ANIMALS: 29 alpacas and 2 llamas. CLINICAL PRESENTATION: Medical records were reviewed to identify camelids with NLD evaluated between 2000 and 2023. Signalment, history, physical examination data, diagnosis, and treatments were recorded. Follow-up information was gathered via phone and email questionnaire. Data were evaluated to determine prevalence and describe signalment and treatments for NLD disease. RESULTS: 31 camelids met the inclusion criteria. A total of 8,027 alpacas and 1,998 llamas were seen within the study period at 1 teaching institution. The prevalence of NLD obstruction for this population of alpacas was 0.3% (26/8,027). Nineteen of 31 (61%) camelids presented at 1 year of age or younger. The most common physical exam finding was ocular discharge (68%). The most common diagnosis was NLD atresia (16/31 [51%]). Patency was established by surgical opening or lavage of the NLD. Long-term follow-up was available for 13 alpacas and 2 llamas, of which 11 (73%) had successful outcomes. CLINICAL RELEVANCE: Results indicate that NLD obstruction is a condition that most commonly affects alpacas < 1 year of age and is associated with a good prognosis for treatment success.


Asunto(s)
Camélidos del Nuevo Mundo , Obstrucción del Conducto Lagrimal , Animales , Obstrucción del Conducto Lagrimal/veterinaria , Obstrucción del Conducto Lagrimal/epidemiología , Masculino , Femenino , Prevalencia , Conducto Nasolagrimal/patología , Hospitales Veterinarios , Estudios Retrospectivos
11.
J Vet Diagn Invest ; 36(3): 473-476, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38520120

RESUMEN

Gastrointestinal adenocarcinomas are often reported in South American camelids (SAC). We describe here cases of gastroduodenal adenocarcinoma in an adult alpaca (Vicugna pacos) and a llama (Llama glama); both SACs were anorectic and lethargic before death. At autopsy, a prominent and firm caudal C3-pyloric-duodenal junction with stricture and ulceration was present in both animals, as were hemorrhages in various organs and hydrothorax. Microscopically, scattered nests, cords, and tortuous acini of neoplastic epithelial cells were embedded in desmoplastic stroma and invaded the submucosa and muscle layers of the gastroduodenal junction. The mucosa was necrotic, with gram-negative rods in the alpaca and colonies of gram-positive cocci in the llama. No tumor metastases were observed. The neoplastic cells immunolabeled for pancytokeratin. Escherichia coli was isolated from the alpaca and Streptococcus lutetiensis from the llama; septicemia was the cause of death in both animals. Although adenocarcinomas arising from gastric compartments and intestinal segments have been reported in SACs, adenocarcinoma of the caudal C3-pyloric-duodenal junction has not been reported previously in these species, to our knowledge.


Asunto(s)
Adenocarcinoma , Camélidos del Nuevo Mundo , Animales , Adenocarcinoma/veterinaria , Adenocarcinoma/patología , Neoplasias Duodenales/veterinaria , Neoplasias Duodenales/patología , Escherichia coli/aislamiento & purificación , Infecciones por Escherichia coli/veterinaria , Infecciones por Escherichia coli/microbiología , Infecciones por Escherichia coli/patología , Resultado Fatal , Sepsis/veterinaria , Sepsis/microbiología , Infecciones Estreptocócicas/veterinaria , Infecciones Estreptocócicas/microbiología , Infecciones Estreptocócicas/patología
12.
Animals (Basel) ; 14(11)2024 May 25.
Artículo en Inglés | MEDLINE | ID: mdl-38891621

RESUMEN

The advances in Assisted Reproductive Technologies (ARTs) applied in South American camelid species are still scarce. The aim of this study was to compare the effects of three semen extenders, before and after the cryopreservation of spermatozoa obtained from the vas deferens, on sperm quality parameters and in vitro fertilization rates of llama (Lama glama) oocytes. Mature fertile llama males (Lama glama; n = 6; age: 48-60 mo.; BCS: ~2.7) were included in the study. Sperm samples were collected from each male using the surgical technique of the vas deferens deviation. Then, the sperm samples were pooled and diluted with the Tris-EY, Andromed®, or BioxCell® extender in order to subsequently carry out the sperm cryopreservation process. The sperm quality assessment related to each extender was performed before and after cryopreservation with regard to sperm morphological abnormalities, acrosome integrity, sperm viability, membrane permeability, and sperm motility traits. Moreover, in vitro fertilization (IVF) procedures were carried out to evaluate the in vitro fertility of the cryopreserved sperm samples using each extender. Overall, significant differences were observed before and after cryopreservation regarding acrosome integrity, sperm viability, membrane permeability, and sperm motility traits among the extenders used, where Tris-EY and Andromed® were better than BioxCell® (p < 0.05); however, no differences were observed regarding the sperm morphological abnormalities among extenders (p > 0.05). Moreover, multiple differences were observed with regard to the velocity and linearity kinematic parameters obtained by computerized analysis before and after the cryopreservation process, irrespective of the extender used (p < 0.05). Finally, differences were observed regarding the in vitro fertilization rates among the different extender-derived samples (p < 0.05). In conclusion, the sperm quality using Tris-EY and Andromed® was better before and after cryopreservation compared to that using BioxCell®. Although the number of fertilized oocytes obtained after the IVF process between Tris-EY and Andromed® was similar, Andromed®-derived samples showed the best sperm quality results before and after cryopreservation. This indicates that the cryopreservation extender is a determining factor in significantly improving in vitro fertilization rates when using sperm samples obtained from vas deferens in llama (Lama glama) males.

13.
Vet Res Commun ; 48(4): 1999-2005, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-38758424

RESUMEN

Lysosomal storage diseases are inherited or acquired disorders characterized by dysfunctional lysosomes that lead to intracytoplasmic accumulation of undegraded substrates, causing impaired cellular function and death. Many acquired lysosomal storage diseases are produced by toxic plants, which have indolizidine alkaloids, including swainsonine, that inhibits lysosomal α-mannosidase and Golgi α-mannosidase II. Swainsonine-induced nervous disease associated with various plants has been reported, including species of the genus Astragalus, Sida, Oxitropis, Swainsona, and Ipomoea. Two species of Astragalus (i.e. Astragalus garbancillo and Astragalus punae) have been found to cause neurologic disease in llamas. In addition, A. garbancillo was also associated with malformations in the offspring, and possibly abortions and neonatal mortality in llamas. The diagnosis of Astragalus spp. intoxication is established based on clinical signs, microscopic and ultrastructural findings, lectin histochemistry, abundance of these plants in the grazing area and determination of swainsonine in plant specimens.


Asunto(s)
Planta del Astrágalo , Swainsonina , Animales , Planta del Astrágalo/química , Enfermedades por Almacenamiento Lisosomal/veterinaria , Enfermedades por Almacenamiento Lisosomal/inducido químicamente , Intoxicación por Plantas/veterinaria , Femenino , Masculino
14.
Anim Reprod Sci ; 252: 107233, 2023 May.
Artículo en Inglés | MEDLINE | ID: mdl-37079995

RESUMEN

The aim of the present study was to evaluate if early administration of progesterone immediately after ovulation affects corpus luteum lifespan in llamas. Female llamas (n = 16) were induced to ovulate by Buserelin injection in the presence of an ovulatory follicle (Day 0). On Day 2, ovulation was confirmed and animals were randomly divided into two groups: treated animals (n = 8) received an intravaginal device containing 0.3 g of progesterone from Day 2 to Day 6 post-induction of ovulation and control group (n = 8) received a device with 0 g of progesterone. Blood samples were collected daily to determine plasma progesterone concentration and transrectal ultrasonographies were performed from Day 7 to Day 12 post-induction of ovulation. Mean maximum diameter of the corpus luteum was significantly lower and was reached before in the treated group than in the control group. The mean highest plasma progesterone concentration and the day that concentration was achieved were similar between groups. However, mean plasma progesterone concentration was significantly higher in the treated group than in the control group on Days 3 and 4 and lower on Days 8 and 9 post-induction of ovulation. The day that plasma progesterone concentration returns to 1 ng/ml differed between groups, occurring earlier in the treated group. In conclusion, the early increase of plasma progesterone concentration during the luteal phase, promoted the premature activation of the luteolytic process affecting corpus luteum function in llamas as it was previously reported in other species.


Asunto(s)
Camélidos del Nuevo Mundo , Progesterona , Femenino , Animales , Progesterona/farmacología , Camélidos del Nuevo Mundo/fisiología , Cuerpo Lúteo/fisiología , Folículo Ovárico/fisiología , Ovulación
15.
Int J Parasitol Parasites Wildl ; 19: 222-242, 2022 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-36388724

RESUMEN

In South America inhabit an endemic group of ungulates adapted to extreme environments: the South American camelids (SAC), a key component of the Andean biocultural heritage. Until today, SAC are the most important factor of Andean economies and social and ritual life. SAC include two wild species, the guanaco (Lama guanicoe) and the vicuña (Vicugna vicugna), and two domestic species, the llama (Lama glama) and the alpaca (Vicugna pacos). Endoparasitosis are one of the most common diseases in SAC, and have great economic and health relevance. Despite this, there is a lack of knowledge on this concern. The main objective of this work was to conduct the first systematic review of the diversity of gastrointestinal parasites of SAC throughout the entire native range of distribution and to identify several gaps in knowledge. The PRISMA protocol was performed and a total of 101 documents were summarized. At least 36 parasitic helminths and five Eimeria spp. were registered. This work highlights the need for a greater number of works to know with more certainty the parasitic fauna of camelids in the past and present, in order to achieve predictions that allow proper management of camelids for their future conservation. Furthermore, concerted research efforts are needed to understand the biology, epidemiology, diagnosis and distribution of the parasitosis of SAC along the entire distribution range to guide conservation decisions.

16.
J Vet Diagn Invest ; 34(4): 674-678, 2022 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-35524435

RESUMEN

Several plants that contain indolizidine alkaloids, including swainsonine, are toxic to livestock, causing dysfunctional lysosomes and storage disease. Swainsonine induces a neurovisceral disease, known as locoism, in sheep, goats, and cattle, which occurs in several parts of the world, including, but not limited to, the western United States, China, and parts of Australia. In South America, locoism has been described in the Andean region of Argentina affecting sheep, cattle, and llamas. Intoxication by consumption of Astragalus punae was suspected in 4 llamas in Jujuy Province, northwestern Argentina. The grazing area contained abundant specimens of A. punae. The clinical course was ~15 d, and included moderate ataxia, incoordination of hindlimbs, and progressive loss of body condition. Microscopically, fine cytoplasmic microvacuolation was observed in the proximal convoluted renal tubules. Ultrastructurally, these changes consisted of severely dilated lysosomes. Swainsonine was detected in stem and leaf samples of A. punae at a concentration of 0.06%. Based on clinical history and signs, histologic and ultrastructural changes, and plant analysis, a diagnosis of swainsonine toxicosis caused by consumption of A. punae was made, which has not been reported previously, to our knowledge.


Asunto(s)
Planta del Astrágalo , Camélidos del Nuevo Mundo , Enfermedades de los Bovinos , Intoxicación por Plantas , Enfermedades de las Ovejas , Animales , Argentina/epidemiología , Bovinos , Intoxicación por Plantas/epidemiología , Intoxicación por Plantas/veterinaria , Ovinos , Enfermedades de las Ovejas/epidemiología , Swainsonina/análisis , Swainsonina/toxicidad
17.
Methods Mol Biol ; 2446: 3-17, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35157266

RESUMEN

The presence of unique heavy chain-only antibodies (HCAbs) in camelids was discovered at Vrije Universiteit Brussel (VUB, Brussels, Belgium) at a time when many researchers were exploring the cloning and expression of smaller antigen-binding fragments (Fv and Fab) from hybridoma-derived antibodies. The potential importance of this discovery was anticipated, and efforts were immediately undertaken to understand the emergence and ontogeny of these HCAbs as well as to investigate the applications of the single-domain antigen-binding variable domains of HCAbs (nanobodies). Nanobodies were demonstrated to possess multiple biochemical and biophysical advantages over other antigen-binding antibody fragments and alternative scaffolds. Today, nanobodies have a significant and growing impact on research, biotechnology, and medicine.


Asunto(s)
Camélidos del Nuevo Mundo , Anticuerpos de Dominio Único , Animales , Anticuerpos/química , Biotecnología , Cadenas Pesadas de Inmunoglobulina , Anticuerpos de Dominio Único/química
18.
J Vet Diagn Invest ; 33(3): 587-590, 2021 May.
Artículo en Inglés | MEDLINE | ID: mdl-33583365

RESUMEN

A 3-mo-old male llama was examined because of a 4-wk history of lethargy and ill thrift. Clinical examination revealed subcutaneous masses in the left prescapular and right inguinal regions, mild ataxia, a slight head tilt to the right, and right ear droop. The cria died before clinical workup was complete. At autopsy, there was generalized lymphadenomegaly, a hepatic nodule, a midbrain mass causing rostral compression of the cerebellum, and internal hydrocephalus. Microscopic findings included pyogranulomatous lymphadenitis, meningoencephalitis, hepatitis, and bronchopneumonia. Intralesional fungal spherules, most consistent with Coccidioides spp., were identified in the lymph nodes, lung, and brain. Fungal culture, single-nucleotide variation genotyping real-time PCR, and DNA sequencing confirmed Coccidioides posadasii. The dam of the cria was native to Arizona and had been moved to Missouri ~2.5 y previously. Agar gel immunodiffusion assay of the herd revealed that only the dam was positive for Coccidioides spp.; 6 herdmates were negative. Computed tomography of the dam revealed multiple nodules within the lungs and liver, which were presumed to be an active coccidioidomycosis infection. This case of systemic coccidioidomycosis in a llama native to Missouri was presumably acquired by vertical transmission from the dam.


Asunto(s)
Camélidos del Nuevo Mundo , Coccidioides/aislamiento & purificación , Coccidioidomicosis/veterinaria , Transmisión Vertical de Enfermedad Infecciosa/veterinaria , Animales , Coccidioidomicosis/diagnóstico , Coccidioidomicosis/patología , Coccidioidomicosis/transmisión , Masculino , Missouri
19.
Animals (Basel) ; 11(5)2021 May 19.
Artículo en Inglés | MEDLINE | ID: mdl-34069466

RESUMEN

Enteric infections are a major cause of neonatal death in South American camelids (SACs). The aim of this study was to determine the prevalence of enteric viral pathogens among alpacas and llamas in Canchis, Cuzco, located in the southern Peruvian highland. Fecal samples were obtained from 80 neonatal alpacas and llamas and tested for coronavirus (CoV), mammalian orthoreovirus (MRV), and rotavirus A (RVA) by RT-PCR. Of the 80 fecal samples analyzed, 76 (95%) were positive for at least one of the viruses tested. Overall, the frequencies of positive samples were 94.1% and 100% among alpacas and llamas, respectively. Of the positive samples, 33 (43.4%) were monoinfected, while 43 (56.6%) had coinfections with two (83.7%) or three (16.3%) viruses. CoV was the most commonly detected virus (87.5%) followed by MRV (50%). RVA was detected only in coinfections. To our knowledge, this is the first description of MRV circulation in SACs or camelids anywhere. These data show that multiple viruses circulate widely among young alpaca and llama crias within the studied areas. These infections can potentially reduce livestock productivity, which translates into serious economic losses for rural communities, directly impacting their livelihoods.

20.
Front Vet Sci ; 7: 598117, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-33335920

RESUMEN

We determined if laterality of ovulation and intrauterine embryo location differentially induces changes in the mesometrial/endometrial vascularization area (MEVA) between uterine horns, during and after embryo migration, elongation and implantation in llamas. Adult, non-pregnant and non-lactating llamas (n = 30) were subjected to daily B-mode ultrasound scanning of their ovaries. Llamas with a growing follicle ≥8 mm in diameter in the left (n = 15) or right (n = 15) ovary were assigned to a single mating with an adult fertile or vasectomized male. Power-doppler ultrasonography was used to determine the MEVA in a cross section of the middle segment of both uterine horns. MEVA was determined by off-line measurements using the ImageJ software. MEVA measurements were performed before mating (day 0) and on days 5, 10, 15, 20, 25, and 30 after mating in pregnant [llamas with left- (n = 6) or right-sided (n = 6) ovulations] and non-pregnant [llamas with left- (n = 6) or right-sided (n = 6) ovulations] females. Ovulation was confirmed by the disappearance of a follicle (≥8 mm) detected previously. Pregnancy was confirmed by the presence of the embryo proper. MEVA was analyzed by one-way ANOVA for repeated measures using the MIXED Procedure in SAS. If significant (P ≤ 0.05) main effects or interactions were detected, Tukey's post-hoc test for multiple comparisons was used. Ovulation rate did not differ (P = 0.4) between females mated to an intact or vasectomized male and between right- or left-sided ovulations. Three females mated to the intact and 3 to the vasectomized male did not ovulate and were excluded of the study. First observation of fluid inside the gestational sac and of embryo proper, were made exclusively in the left uterine horn, on day 15.8 ± 3.8 and 22 ± 2.7, and 16.7± 2.6 and 27.5 ± 2.8 for pregnant llamas ovulating in the right and left ovary, respectively. Although the MEVA of both uterine horns was affected by time (P < 0.05), it was not affected by physiological status (pregnant vs. non-pregnant; P = 0.9) or laterality of ovulation (P = 0.4). Contrary to expectations, regardless of the laterality of ovulation, in pregnant llamas the left horn did not display a greater MEVA before or after embryo arrival, a trend that was observed during the first 30 days of gestation.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA