World Camelids Research Articles

Reproductive physiology in female Old World Camelids

This review summarizes the basic reproductive physiology of dromedary and Bactrian camels. Camels are seasonal breeders with a relatively short breeding season during the cooler months. The onset of the breeding season can be influenced by local environmental factors such as temperature and pasture availability although decreased libido of the male as the environmental temperature increases is also a factor. Oestrous behaviour is highly variable in duration and intensity and is therefore unreliable for the detection of oestrus and difficult to relate to follicular activity in the ovaries. Camels are induced ovulators and thus normally only ovulate in response to mating. In the absence of mating, ovarian follicles tend to regress after a period of growth and maturity, whereas if male and females are kept together the female gets mated when the dominant follicle measures between 1.3 and 1.7 cm in diameter and the corpus luteum that develops has a lifespan of only 10–12 days. Peripheral concentrations of oestradiol increase with increasing follicle diameter until the follicle reaches 1.7 cm in diameter at which time they start to decrease even if the follicle continues to grow. The concentrations of progesterone remains low in non-mated animals but in mated camels it increases 3–4 days after ovulation (day of ovulation = Day 0) to reach maximum concentrations on Days 8–9 before decreasing rapidly on Days 10–11 in the non-pregnant animal. Ovulation can also be reliably induced using either Gonadotrophin Releasing Hormone (GnRH) or human Chorionic Gonadotrophin (hCG) but only when the follicle measures between 1.0 and 1.9 cm in diameter. Ovulation does not typically occur from follicles that grow beyond 2.0 cm in diameter but these follicles typically develop echogenic strands of fibrin as the follicle degenerates. The gestation period of camels is 13 months but the time of resumption of follicular activity following parturition is highly variable and influenced by nutritional status and lactation. Females that lose their offspring or have offspring which are weaned have a mature follicle develop within 10–12 days whilst in well-fed lactating females mature follicles do not develop until 30–60 days postpartum.

Comparative analysis of walking gaits in South American camelids

Although several studies on the locomotion of Old World camels, mainly the dromedary Camelus dromedarius, exist, detailed data on their relatives, the New World camelids are very scarce. Camelids are distinguished from most mammals by their pacing gaits, a pace-like walk and running pace. We conducted detailed video analyses of undisturbed walking in the alpaca Lama pacos and llama Lama glama and compared these with observations of the dromedary and domestic warmblood horses Equus caballus. The average walking speed, stride length and stride frequency (mean±sd) were 0.97±0.15 m s−1, 0.94±0.08 m and 1.03±0.08 s−1 for alpacas and 1.13±0.12 m s−1, 1.18±0.08 m and 0.95±0.05 s−1 for llamas, respectively. The mean support phase (mean±sd) was 0.67±0.11, 0.72±0.10 and 1.11±0.14 s for llama, horse and dromedary, respectively, corresponding to 58.9±3.8, 61.7±3.2 and 66.0±1.2%, respectively. We found remarkable differences between New and Old World camelids. Contrary to the dromedary, alpacas and llamas in our study did not perform a symmetrical running pace. The lateral time lag was shortest in the llama, decreasing with increasing speed from 15 to 5% with an average of 10%.

IMAGING DIAGNOSIS-DORSAL MEDIASTINAL T-CELL LYMPHOMA IN AN ALPACA

A 14-year-old male alpaca had refractory pleural effusion. The cause of the effusion was not apparent either radiographically or sonographically, or following a pleural fluid cytologic examination. Using computed tomographic (CT) examination, a dorsal paravertebral mass was identified and similar masses were found in the cranial mediastinum, retroperitoneal space, and adjacent to the hepatic entry of the portal vein. The histopathologic diagnosis was multicentric T-cell lymphoma. CT examination may prove to be a valuable imaging modality in the localization and staging of neoplasia in new world camelids.

Preputial microflora of llamas (Lama glama) and alpacas (Vicugna pacos)

Abstract To characterize the normal preputial microflora of healthy male New World camelids (NWC), samples were swabbed from the preputial mucosa of 23 intact and 7 castrated males including 17 llamas and 13 alpacas ranging from 1 day to 16 years of age. The swabs were streaked onto tryptose blood agar with 5% bovine blood, MacConkey's agar, Karmali Campylobacter selective agar and Saboraud's dextrose agar and cultured under aerobic, micro-aerophilic and/or anaerobic conditions. Bacteria but not fungi or Campylobacter were isolated from all 30 animals. The mean numbers of bacterial isolates obtained per male were 3.4 for alpacas (range 2–6), 4.0 for llamas (range 1–7) and 3.7 for both species combined. Of 22 bacterial genera identified from a total of 112 isolates, five were aerobes, 11 were facultative anaerobes and six were obligate anaerobes. Nine isolates failed to subculture and could not be identified. The most frequently isolated genera in descending order of frequency were Staphylococcus, Bacillus, Streptococcus, Bacteroides, Corynebacterium, Arcanobacterium and Actinomyces. This is the first description of the microflora present on the preputial mucosa of healthy llamas and alpacas. Most of the bacteria isolated from the prepuce are considered commensal organisms, but several could be opportunistic pathogens under appropriate conditions.

Ovarian follicular dynamics and hormonal secretory profiles in guanacos ( Lama guanicoe)

The objective of the present study was to describe ovarian activity in 11 adult non-mated guanacos, evaluated every second day for 40 days by transrectal ultrasonography and by plasma estradiol-17β and progesterone concentrations. An inverse relationship ( r = −0.29, P < 0.001) was observed between the diameter of the largest ovarian follicle and the total number of follicles indicating that follicular growth in guanacos occurs in waves. The mean duration of follicular wave was 15.1 ± 4.2 days with a range from 9 to 26. The follicular growth phase was 7.0 ± 2.4 days, the static phase 3.0 ± 1.2 days, the regression phase 5.2 ± 2.1 days and the inter-wave interval was 12.6 ± 5.6 days. The maximum follicular diameter in each follicular wave was 10.2 ± 2.1 mm with a range from 7.2 to 16.1 mm. Inter-wave intervals of longer duration were associated with a larger maximum follicle diameter ( P < 0.001). Follicular activity alternated between ovaries in 93% of the waves with 48% of dominant follicles occurring in the left and 52% in the right ovary without differences ( P > 0.05). Plasma estradiol-17β concentrations showed a wave-like pattern, varying from 20.0 to 92.1 pmol/L. Plasma progesterone concentrations remained below 1 nmol/L without any ultrasonic evidence of ovulation during the study. These results in guanacos suggest a follicular wave pattern more similar to the llama ( Lama glama) than previously described in other South American and Old World camelid species.

Oleander intoxication in New World camelids: 12 cases (1995–2006)

To characterize the clinical and clinicopathologic effects and evaluate outcome associated with oleander toxicosis in New World camelids. Retrospective case series. 11 llamas and 1 alpaca. Medical records from a veterinary medical teaching hospital from January 1, 1995, to December 31, 2006, were reviewed. Records of all New World camelids that had detectable amounts of oleandrin in samples of serum, urine, or gastrointestinal fluid were included in the study. Descriptive statistics were used to evaluate the history, physical examination findings, clinicopathologic data, and outcome of affected camelids. 11 llamas and 1 alpaca met the inclusion criteria of the study. Either oleander plants were present where the camelids resided (n = 7) or oleander plant material was identified in the hay fed to the camelids (5). One llama was dead on arrival at the hospital, and another was euthanized upon admission because of financial concerns. Of the 10 treated camelids, 9 had evidence of acute renal failure, 7 had gastrointestinal signs, and 4 had cardiac dysrhythmias on initial evaluation. The overall mortality rate was 25%, but the mortality rate for the 10 camelids that were medically treated was 10%. In New World camelids, oleander intoxication was associated with a triad of clinical effects (ie, renal, gastrointestinal, and cardiovascular dysfunction). Oleander intoxication often represented a herd problem but carried a fair to good prognosis if treated promptly. Oleander toxicosis should be considered a differential diagnosis in sick camelids.

Seroprevalence and characterization of pestivirus infections in small ruminants and new world camelids in Switzerland

The seroprevalence of pestivirus infections in small ruminants and new world camelids in Switzerland was determined. In 5'059 sera of sheep from 382 herds, 503 sera of goats from 54 herds and 109 sera of alpacas and lamas from 53 herds, population prevalences of 16.1% (sheep), 25.4% (goats) and 4.6% (new world camelids), respectively, were found. In order to determine the source of infection, the serological reactions were further characterized by cross-neutralization against two pestiviruses representing the genotypes BVDV (Bovine Virus Diarrhea Virus)-1 and BDV (Border Disease Virus)-1. Based on the ratio of respective antibody titres, 56.1% of the infections in sheep were induced by a BDV-1, 12.9% by a BVDV-1 and 31.0% by an unresolved pestivirus. In goats, the corresponding proportions were 23.4%, 10.2% and 66.4%, respectively. In Alpacas and Lamas, the source of infection of 1 animal was BDV-1 and that of 4 seropositive animals remained unresolved. In view of the phylogenetic relationship between pestiviruses, the unresolved source of infection is most probably attributable to other pestivirus genotypes circulating in small ruminants and new world camelids. Due to the predominance of pestiviral genotypes other than BVDV-1, the risk of transmission of BVDV from persistently infected small ruminants and new world camelids to cattle appears to be moderate, apart from close direct contact in mixed animal husbandry, communal pasturing and grazing in the Alps.

Metastatic Malignant Melanoma in an Alpaca (Vicugna Pacos)

A case of malignant melanoma in a 7-year-old, intact, black, male Huacaya alpaca with a history of a chronic, nonhealing wound involving the left external nostril, weight loss, and inappetence is described. Malignant melanoma was diagnosed by histology of punch biopsy specimens from a mass on the maxilla associated with the nonhealing wound and from a mass in the submandibular region. The alpaca was humanely euthanized 10 days after the diagnosis on the basis of the poor prognosis and rapid clinical deterioration. At postmortem examination, the alpaca had an ulcerated, multilobulated, black pigmented mass (8.0 cm x 6.0 cm x 4.0 cm) that infiltrated the left rostral maxilla extending into the marrow space and into the left nasal cavity. Numerous, discrete, coalescing masses were present in the subcutaneous tissue of the submandibular area, peritracheal connective tissue, pericardium, and diaphragmatic parietal pleura and were disseminated throughout the pulmonary parenchyma. The masses were diffusely black on cut surface and exuded black pigment. Histologically, all masses were composed of spindloid to polygonal cells with indistinct cell borders and moderate amounts of cytoplasm that contained abundant fine, black granules (melanin), confirming metastasis of a primary mucocutaneous melanoma. To the authors' knowledge, this is the first report of a malignant melanoma involving bone in a New World camelid.

Interspecies embryo transfer in camelids: the birth of the first Bactrian camel calves (Camelus bactrianus) from dromedary camels (Camelus dromedarius)

Interspecies embryo transfer is a possible approach that can be used to conserve endangered species. It could provide a useful technique to preserve the Iranian and wild Bactrian camels, both of which are threatened with extinction. In the present study, one Bactrian camel was superovulated using decreasing doses of FSH (60, 40, 30, 30, 20, 20 mg, b.i.d.; Folltropin-V; Bioniche, London, ON, Canada) for 6 days, followed by a single injection of FSH (20 mg, i.m.) on Day 7. Daily ovarian ultrasonography was performed until most of the growing follicles had reached a mature size of 13-17 mm, at which time the camel was mated twice, 24 h apart, with a fertile male Bactrian camel. At the time of first mating, female camels were given 20 microg, i.v., buserelin (Receptal; Intervet, Boxmeer, The Netherlands). One day after the donor camel had been mated, the dromedary recipients (n = 8) were injected with 25 mg, i.v., porcine LH (Lutropin-V; Bioniche) to induce ovulation. Embryos were recovered on Day 8.5 after the first mating and transferred non-surgically into recipients on Day 7.5 after LH injection. Pregnancy was diagnosed 25 days after embryo transfer. Healthy Bactrian camel calves (n = 4) were born without any particular complications at the time of parturition (e.g. dystocia and neonatal diseases). The present study is the first report of the birth of Bactrian camel calves from dromedary camels, as well as the first report of interspecies embryo transfer in old world camelids.

Management of Dystocia in Camelids

Dystocia is the most common emergency in camelid practice. The aim of the present paper is to review the most important clinical features of normal parturition and to discuss obstetrical situations in camelids and their non-surgical and surgical management, including prepartum and term uterine torsion. This clinical review includes both Old and New World camelids.

Small Ruminant and Camelid Critical Care Tips and Tricks

Small ruminant and camelid veterinary medicine can be an important and economically viable portion of veterinary practice. The evolution of small ruminant and camelid owners has put veterinarians in the position to be expected to provide more extensive care for some of these patients. The New World Camelid industry continues to grow in the United States, although it is uncertain how long this growth will be sustained. The sale prices for New World Camelids remain high and due to the investment nature of these animals, owners will often seek high-level veterinary care. In addition, owners are obligated to seek appropriate medical treatment of animals with mortality insurance and this may necessitate more extensive medical care. There is also an increase in the number of owners raising pet livestock, in particular sheep and goats. These clients will often pursue veterinary medical care that is in excess of the monetary value of the animal. For these reasons, it is important for practitioners working with these species to be familiar with basic critical care techniques.&#x0D; The methods described are developed from the collective experiences of clinicians at the Colorado State University James L. Voss Veterinary Teaching Hospital. While these methods are biased toward the types of routine and tertiary cases that we see, they will provide the general practitioner with many tools to treat routine and critical care patients. The topics and key concepts presented can be put to use immediately in a veterinary practice.

Quantification of the DNA Difference, and Separation of X‐ and Y‐Bearing Sperm in Alpacas (Vicugna pacos)

Sperm sexing is an emerging reproductive technology which has been successfully used to produce offspring of a pre-determined sex in domestic and wildlife species but has yet to be applied to New World camelids. The aims of the present study were to (i) optimize the Hoescht 33342 (H33342) staining concentration for the flow cytometric separation of X and Y chromosome-bearing alpaca (Vicugna pacos) sperm nuclei, (ii) separate alpaca sperm nuclei into high purity (>90%) populations bearing the X- and Y-chromosome and (iii) determine the DNA difference between X- and Y-bearing sperm in alpacas. Semen was collected from alpacas and sperm nuclei stained with H33342, incubated and analysed using a high-speed cell sorter (SX-MoFlo). H33342 staining concentrations of 36, 54, 72 or 90 microm did not affect the proportion of correctly oriented sperm nuclei (43.3 +/- 3.9, 46.4 +/- 3.7, 44.5 +/- 4.0 and 51.1 +/- 2.5% respectively) nor the speed of sorting (1381 +/- 160, 1386 +/- 123, 1371 +/- 133 and 1379 +/- 127 sperm nuclei/s). Sort reanalysis determined high levels of purity for X- and Y-enriched populations (96.6 +/- 0.7% and 96.1 +/- 1.1% respectively). The DNA difference, based on fluorescence intensity (determined by the SX-MoFlo), was 3.8 +/- 0.06%. These data demonstrate for the first time that alpaca sperm nuclei can be separated into high purity populations and the potential for applying sperm sexing technology to New World camelids.

Third‐Degree Atrioventricular Block in a Horse Secondary to Rattlesnake Envenomation

Third‐Degree Atrioventricular Block in a Horse Secondary to Rattlesnake Envenomation

Ciliate protozoa of the forestomach of llamas (Lama glama) and alpacas (Vicugna pacos) from the Bolivian Altiplano

Protozoal diversity in the forestomach of South American camelids (SAC) was studied in eight llamas and six alpacas from the Parque Natural Condoriri (3900 to 4100 m altitude, Departamento La Paz, Bolivia). Total protozoal concentrations were 3.6 times higher (P &lt; 0.001) in the stomach contents of alpacas (39.6 x 10 4 ml -1 and 143.8 x 10 4 ml -1 in llamas and alpacas, respectively). Four to 11 species, all from the genus Entodinium, were observed in llamas, whereas from eight to nine species of Entodinium and minor proportions of Diplodinium (D. anisacanthum, D. dogieli, D. rangiferi), Eudiplodinium (E. bovis, E. maggii, E. neglectum) and Epidinium (E. ecaudatum) were observed in alpacas. The presence of Epidinium species in the alpaca is a new host record. The vestibuliferids, Dasytricha and Isotricha were absent from the forestomach of SAC, as well as other species such as Caloscolex genus, Diplodinium cameli and Entodinium ovumrajae, commonly found in Old World camelids.

Eimeria macusanuensis Infection in New World Camelids

Eimeria macusanuensis is an important coccidian intestinal parasite of New World camelids. It may be the same parasite as E. camelli, a similar-appearing intestinal coccidian of Old World camels, but this has not been proven. Eimeria macusanuensis affects all ages of camelid, not just juveniles. Its contribution to illness may not be appreciated, since some camelids become sick up to two weeks before patent infections are detected in their herdmates. Gross lesions are often absent, and histological lesions can be so segmental that they are missed on routine necropsy.

A complete mitochondrial genome sequence of the wild two-humped camel (Camelus bactrianus ferus): an evolutionary history of camelidae

BackgroundThe family Camelidae that evolved in North America during the Eocene survived with two distinct tribes, Camelini and Lamini. To investigate the evolutionary relationship between them and to further understand the evolutionary history of this family, we determined the complete mitochondrial genome sequence of the wild two-humped camel (Camelus bactrianus ferus), the only wild survivor of the Old World camel.ResultsThe mitochondrial genome sequence (16,680 bp) from C. bactrianus ferus contains 13 protein-coding, two rRNA, and 22 tRNA genes as well as a typical control region; this basic structure is shared by all metazoan mitochondrial genomes. Its protein-coding region exhibits codon usage common to all mammals and possesses the three cryptic stop codons shared by all vertebrates. C. bactrianus ferus together with the rest of mammalian species do not share a triplet nucleotide insertion (GCC) that encodes a proline residue found only in the nd1 gene of the New World camelid Lama pacos. This lineage-specific insertion in the L. pacos mtDNA occurred after the split between the Old and New World camelids suggests that it may have functional implication since a proline insertion in a protein backbone usually alters protein conformation significantly, and nd1 gene has not been seen as polymorphic as the rest of ND family genes among camelids. Our phylogenetic study based on complete mitochondrial genomes excluding the control region suggested that the divergence of the two tribes may occur in the early Miocene; it is much earlier than what was deduced from the fossil record (11 million years). An evolutionary history reconstructed for the family Camelidae based on cytb sequences suggested that the split of bactrian camel and dromedary may have occurred in North America before the tribe Camelini migrated from North America to Asia.ConclusionMolecular clock analysis of complete mitochondrial genomes from C. bactrianus ferus and L. pacos suggested that the two tribes diverged from their common ancestor about 25 million years ago, much earlier than what was predicted based on fossil records.

Antibody responses in New World camelids with tuberculosis caused by Mycobacterium microti

Antibody responses in New World camelids (NWC) infected with Mycobacterium microti were studied by two serological methods, multiantigen print immunoassay (MAPIA) and lateral-flow-based rapid test (RT). Serum samples were collected during 2004–2006 from 87 animals including 1 alpaca and 7 llamas with confirmed or suspected M. microti infection, 33 potentially exposed but clinically healthy animals from known infected herds, and 46 control NWC from herds where infection had not been previously diagnosed. The serological assays correctly identified infection status in 97% (MAPIA) or 87% (RT) cases. In three llamas with confirmed M. microti infection and one llama with gross pathology suggestive of disease, for which multiple serum samples collected over time were available, the antibody-based tests showed positive results 1–2 years prior to the onset of clinical signs or being found dead. In MAPIA, MPB83 protein was identified to be an immunodominant serological target antigen recognized in NWC infected with M. microti. With the limited number of animals tested in this study, the serological assays demonstrated the potential for convenient, rapid, and accurate diagnosis of M. microti infection in live llamas and alpacas.

Analysis of the genome sequence of an alpaca coronavirus

Coronaviral infection of New World camelids was first identified in 1998 in llamas and alpacas with severe diarrhea. In order to understand this infection, one of the coronavirus isolates was sequenced and analyzed. It has a genome of 31,076 nt including the poly A tail at the 3′ end. This virus designated as ACoV-00-1381 (ACoV) encodes all 10 open reading frames (ORFs) characteristic of Group 2 bovine coronavirus (BCoV). Phylogenetic analysis showed that the ACoV genome is clustered closely (> 99.5% identity) with two BCoV strains, ENT and LUN, and was also closely related to other BCoV strains (Mebus, Quebec, DB2), a human corona virus (strain 043) (> 96%), and porcine hemagglutinating encephalomyelitis virus (> 93% identity). A total of 145 point mutations and one nucleotide deletion were found relative to the BCoV ENT. Most of the ORFs were highly conserved; however, the predicted spike protein (S) has 9 and 12 amino acid differences from BCoV LUN and ENT, respectively, and shows a higher relative number of changes than the other proteins. Phylogenetic analysis suggests that ACoV shares the same ancestor as BCoV ENT and LUN.

Surgical repair of femoral fractures in New World camelids: five cases (1996–2003)

Five New World camelids were admitted to the Western College of Veterinary Medicine between 1996 and 2003 for evaluation of femoral fractures. There were three alpacas and two llamas. Four of the animals were female and three were less than 3 months of age. Fracture configurations consisted of distal physeal fractures (three), a comminuted diaphyseal/metaphyseal fracture, and a transverse diaphyseal fracture. Fractures were diagnosed with a combination of physical examination and radiographs in all cases. All five fractures were repaired with internal fixation and three animals were discharged from the hospital with fractures that healed. One cria underwent successful internal fixation but died from pulmonary oedema during recovery from anaesthesia. Postoperative complications were rare and limited to inadequate fracture stability in one alpaca and prolonged recovery to weight bearing in another. One llama with a comminuted metaphyseal fracture, repaired with a 4.5 mm dynamic compression plate, subsequently had catastrophic failure of the bone 17 days after surgery. Overall the clients were pleased with the outcome of discharged animals. Although femoral fractures are considered rare, they pose a unique opportunity for the large animal veterinarian to successfully achieve fracture union with the aid of internal fixation.

Efficacy of topical eprinomectin in the treatment ofChorioptessp. infestation in alpacas and llamas

Chorioptes sp. mite infestation is increasingly recognized as a cause of skin disease in New World camelids and there is a need for an effective treatment protocol to eliminate herd infestation. In this field trial, eprinomectin applied topically at the rate of 0.5 mg kg(-1) weekly for 10 weeks was found to be ineffective in a herd of 12 llamas and 16 alpacas.