Adult Dromedaries Research Articles

Early postmortem degradation of actin muscle protein in Algerian Sahraoui dromedaries.

The present study aimed to evaluate actin degradation during the early postmortem time in Longissimus Lumborum muscle according to Sahraoui dromedary's age. A sample of eight males, young (2 years old) and adult (8 years old) dromedaries, was used to investigate meat quality traits and actin proteolysis during the conversion of muscle to meat. Results demonstrated higher pH values in young compared to adult with a polyphasic pH drop profile. While, age did not affect drip loss (DL) and the values at 72 h postmortem varied from 5 to 9%. Western blot revealed that actin proteolysis occurred since 1 h postmortem and that it was affected by age and postmortem time. In particular, the 32 and 25 kDa actin fragments could be potential markers of ongoing meat tenderization.

Immunoreactivity Of Alpha Smooth Muscle Actin In The Epididymis Of The Dromedary Camel: Impact Of The Sexual Maturity And The Breeding Seasonality

This study was carried out to highlight the seasonal variation of the immunoreactivity of the protein alpha smooth muscle actin (a-SMA), within the epididymal duct of the male dromedaries. Immunostaining for detection of a-SMA was applied on paraffin-embedded sections taken from different regions of the epididymal duct from both juvenile and adult dromedaries, during the different seasons of the year. Immunoreactivity (IR) was mainly confined to the smooth muscle cells (SMCs) within the peritubular muscle coat and in the walls of the blood vessels. The intensity of IR displayed a remarkable seasonal variation in adults. The strongest IR has been recorded in all epididymal regions (head, body and tail), during the breeding season (corresponds to winter months). In the season of breeding inactivity (corresponds to summer months), the a-SMA-IR exhibited the lowest intensity. During the period of transition from activity to inactivity (corresponds to spring months) and from inactivity to activity (corresponds to autumn months), a moderate a-SMA-IR has been reported. On the other hand, a weak to moderate immunoreactivity for a-SMA appeared mainly in innermost layers of the peritubular cells surrounding the epididymal duct of the juvenile dromedaries throughout the year. In conclusion, both of the sexual maturity and the breeding seasonality demonstrated a clear impact on the immunostaining for a-SMA in male dromedaries. This may be relevant to the physiological alterations that are linked to hormonal control throughout the year.

Trypanosoma evansi In a dromedary camel herd in the UAE-PART II

Trypanosoma evansi infection was diagnosed in 15 out of 17 adult dromedaries of a breeding herd in the Emirate of Dubai. The herd had a history of abortions in the previous years. Own observations on 16 adult females and one bull lasted 12 months and revealed trypanosomosis in 15 animals in monthly haematological and serological examinations. Despite three to four injections of the trypanocides melarsamine and/or quinapyramine, only one camel was cured. One camel aborted in the 8th month of pregnancy. Four other dams delivered healthy calves.

A systematic review of MERS-CoV seroprevalence and RNA prevalence in dromedary camels: Implications for animal vaccination

Human infection with Middle East Respiratory Syndrome Coronavirus (MERS-CoV) is driven by recurring dromedary-to-human spill-over events, leading decision-makers to consider dromedary vaccination. Dromedary vaccine candidates in the development pipeline are showing hopeful results, but gaps in our understanding of the epidemiology of MERS-CoV in dromedaries must be addressed to design and evaluate potential vaccination strategies. We aim to bring together existing measures of MERS-CoV infection in dromedary camels to assess the distribution of infection, highlighting knowledge gaps and implications for animal vaccination. We systematically reviewed the published literature on MEDLINE, EMBASE and Web of Science that reported seroprevalence and/or prevalence of active MERS-CoV infection in dromedary camels from both cross-sectional and longitudinal studies. 60 studies met our eligibility criteria. Qualitative syntheses determined that MERS-CoV seroprevalence increased with age up to 80–100% in adult dromedaries supporting geographically widespread endemicity of MERS-CoV in dromedaries in both the Arabian Peninsula and countries exporting dromedaries from Africa. The high prevalence of active infection measured in juveniles and at sites where dromedary populations mix should guide further investigation – particularly of dromedary movement – and inform vaccination strategy design and evaluation through mathematical modelling.

Histomorphometric evaluation of dromedarian (Camelus dromedarius) heart

The primary objective of present study was comprehensive exploration of age related cardiac anatomy of camel which might be helpful for appropriate understanding of CVDs. Seven hearts of each, young (1–2 years) and adult (>5 years), group were collected and dissected for macroscopic and microscopic evaluation. Tissue sections were prepared by paraffin tissue technique and morphometry was done using Image J ®. Means of all parameters were compared by student T-Test. In macroscopic evaluation relative weight of heart was found significantly (P<0.05) higher in young dromedaries while absolute weight, circumference, thickness of left ventricle wall, width of moderator band and thickness of aortic wall along with lumen were found significantly (P<0.05) higher in adult dromedaries. Microscopic parameters of heart like thickness of endocardium, sub-endocardium and the purkinje fibres diameter were found significantly (P<0.01) thicker in adults than young dromedaries; however, it was otherwise for sub-endothelium. Parenchymal percentage in myocardium was found significantly (P<0.01) lower in young than adult dromedaries, however, the stromal content followed the inverse pattern. These cardiac anatomical results can be implicated for legitimate understanding of CVDs.

Two novel dromedary camel bocaparvoviruses from dromedaries in the Middle East with unique genomic features.

The recent emergence of Middle East respiratory syndrome (MERS) coronavirus and its discovery from dromedary camels has boosted interest in the search for novel viruses in dromedaries. While bocaparvoviruses are known to infect various animals, it was not known that they exist in dromedaries. In this study, we describe the discovery of two novel dromedary camel bocaparvoviruses (DBoVs), DBoV1 and DBoV2, from dromedary faecal samples in Dubai. Among 667 adult dromedaries and 72 dromedary calves, 13.9 % of adult dromedaries and 33.3 % of dromedary calves were positive for DBoV1, while 7.0 % of adult dromedaries and 25.0 % of dromedary calves were positive for DBoV2, as determined by PCR. Sequencing of 21 DBoV1 and 18 DBoV2 genomes and phylogenetic analysis showed that DBoV1 and DBoV2 formed two distinct clusters, with only 32.6-36.3 % amino acid identities between the DBoV1 and DBoV2 strains. Quasispecies were detected in both DBoVs. The amino acid sequences of the NS1 proteins of all the DBoV1 and DBoV2 strains showed <85 % identity to those of all the other bocaparvoviruses, indicating that DBoV1 and DBoV2 are two bocaparvovirus species according to the ICTV criteria. Although the typical genome structure of NS1-NP1-VP1/VP2 was observed in DBoV1 and DBoV2, no phospholipase A2 motif and associated calcium binding site were observed in the predicted VP1 sequences for any of the 18 sequenced DBoV2, and no start codons were found for their VP1. For all 18 DBoV2 genomes, an AT-rich region of variable length and composition was present downstream to NP1. Further studies will be crucial to understand the pathogenic potential of DBoVs in this unique group of animals.

Life cycle and morphology of development stages of Physocephalus dromedarii (Nematoda: Spirocercidae)

ObjectiveTo study the development of Physocephalus dromedarii (P. dromedarii) in the final host. MethodsFor this, 5 adult dromedaries were orally infected with third larval stages of P. dromedarii obtained from naturally infected scarab beetles (Scarabaeus cristatus). The camels were necropsied 14, 42, 70, 84 and 280 days after infection and their abomasi were examined for the presence of nematodes. ResultsEarly 4th stage larva occurred already 2 weeks after infection. They were still in the sheet of the 3rd stage larva. Six weeks after infection, the nematodes became juvenile male and female adults measuring 9 and 10 mm, respectively. Their size doubled at 10 weeks post infection and patency was reached at 12 weeks. P. dromedarii was still present in the camel that was examined 40 weeks after infection. ConclusionsAs a result of experimental infection of the natural host, the determined prepatent period of P. dromedarii equalled 12 weeks.

Histologic developmental horizons of the prenatal dromedary tongue

We present a study on the histologic developmental horizons of the dromedary tongue using abattoir samples. The 13 month dromedary gestation period was divided into four quarters, giving the dromedary four prenatal growth phases. Feotuses were recovered from slaughtered camels and 1 cm2 samples were cut from dorsum and lateral parts of the apex, body and base of tongues of associated foetuses in each growth phase for histological analysis. The dorsal and lateral parts of the apex of the tongue showed variable sizes of underdeveloped filiform and fungiform papillae formed from the folding of non - keratinized stratified squamous epithelium. The filiform papillae were interspersed with fungiform papillae. A brief glandless propria-submucosa of vascularized connective tissue was continuous with their lamina epithelialis. The muscularis showed vertical, longitudinal and transverse (X, Y, Z) directions of skeletal muscles. Same arrangement was found at the lingual body. Under- developed lentiform papillae extended from the terminus of the caudal aspect of the lingual body to the rostral aspect of the lingual base. The lingual base showed underdeveloped fungiform and vallate papillae. The lingual body and base were highly muscularized. The muscularity became more obvious at the second and third quarters. Unique to the third phase was apical keratinization of filiform papillae, marking its full development. The propria-submucosa was highly vascularized. The fourth growth phase marked the stage for full development of most of parts of the tongue except the mucosa of the lingual base, where taste buds were not observed in gustatory papillae, eventhough an earlier study had observed taste buds in gustatory papillae of the adult dromedary. It was concluded that most of the salient features of the postnatal dromedary tongue, such as gustatory and non-gustatory papillae, were already evident as early as the first growth phase.Keywords: Dromedary, Foetus, Histology, Prenatal development, Tongue

Gross morphology and morphometry of foetal and adult dromedary tongues

Gross morphology and morphometry of apparently normal tongues of forty antenatal and ten adult dromedaries (Camelus dromedarius) of both sexes, procured from the Maiduguri Metropolitan abattoir, were studied. This was with the aim of documenting information on these aspects. The thirteen months dromedary gestation period was divided into four quarters for the purpose of the foetal tongue morphometric study, with ten foetuses per quarter. The prenatal and postnatal tongues were grossly observed to be flat apically and oval basally. They were highly flexible, like other ruminants’ tongues, and relatively small to the overall sizes of the study animals. The highest lingual weight percentage of the body weight of 0.39% was attained at the second prenatal growth phase of the dromedary while the least, 0.16%, was attained in the adult. The foetal tongues showed levels of significant increases in sizes and weights throughout the prenatal growth phases. It was concluded that the dromedary tongue is similar to other ruminant tongues and most of the salient gross features, like gustatory and non-gustatory papillae, of the dromedary tongue were already obvious as early as the first prenatal growth phase (2 – 3 months) and the remaining three periods were associated with size increases. In the prenatal dromedary tongues studied, the salient gross features of the tongue were fully evident right from the first quarter of gestation (first three months of prenatal life), but were relatively small in size. Likewise; the mean dimensions and the weights obtained in the present study, showed significant increments across the four-quarters gestation. This is not unrelated with the structural developments of the overall body size and weights.Keywords: Adult, Dromedary, Foetus, Morphometry, Tongue

A novel astrovirus from dromedaries in the Middle East.

The recent emergence of Middle East respiratory syndrome coronavirus from the Middle East and its discovery from dromedary camels has boosted interest in the search for novel viruses in dromedaries. The existence of astroviruses (AstVs) in dromedaries was previously unknown. We describe the discovery of a novel dromedary camel AstV (DcAstV) from dromedaries in Dubai. Among 215 dromedaries, DcAstV was detected in faecal samples of four [three (1.5 %) adult dromedaries and one (8.3 %) dromedary calf] by reverse transcription-PCR. Sequencing of the four DcAstV genomes and phylogenetic analysis showed that the DcAstVs formed a distinct cluster. Although DcAstV was most closely related to a recently characterized porcine AstV 2, their capsid proteins only shared 60-66 % amino acid identity, with a mean amino acid genetic distance of 0.372. Notably, the N-terminal halves of the capsid proteins of DcAstV shared ≤ 85 % amino acid identity, but the C-terminal halves only shared ≤ 49 % amino acid identity compared with the corresponding proteins in other AstVs. A high variation of the genome sequences of DcAstV was also observed, with a mean amino acid genetic distance of 0.214 for ORF2 of the four strains. Recombination analysis revealed a possible recombination event in ORF2 of strain DcAstV-274. The low Ka/Ks ratios (number of non-synonymous substitutions per non-synonymous site to number of synonymous substitutions per synonymous site) of the four ORFs in the DcAstV genomes supported the suggestion that dromedaries are the natural reservoir where AstV is stably evolving. These results suggest that AstV is a novel species of the genus Mamastrovirus in the family Astroviridae. Further studies are important to understand the pathogenic potential of DcAstV.

A novel dromedary camel enterovirus in the family Picornaviridae from dromedaries in the Middle East.

The recent emergence of Middle East respiratory syndrome coronavirus from the Middle East and the discovery of the virus from dromedary camels have boosted interest in the search for novel viruses in dromedaries. Whilst picornaviruses are known to infect various animals, their existence in dromedaries was unknown. We describe the discovery of a novel picornavirus, dromedary camel enterovirus (DcEV), from dromedaries in Dubai. Among 215 dromedaries, DcEV was detected in faecal samples of four (1.9 %) dromedaries [one (0.5 %) adult dromedary and three (25 %) dromedary calves] by reverse transcription PCR. Analysis of two DcEV genomes showed that DcEV was clustered with other species of the genus Enterovirus and was most closely related to and possessed highest amino acid identities to the species Enterovirus E and Enterovirus F found in cattle. The G+C content of DcEV was 45 mol%, which differed from that of Enterovirus E and Enterovirus F (49-50 mol%) by 4-5 %. Similar to other members of the genus Enterovirus, the 5' UTR of DcEV possessed a putative type I internal ribosome entry site. The low ratios of the number of nonsynonymous substitutions per non-synonymous site to the number of synonymous substitutions per synonymous site (Ka/Ks) of various coding regions suggested that dromedaries are the natural reservoir in which DcEV has been stably evolving. These results suggest that DcEV is a novel species of the genus Enterovirus in the family Picornaviridae. Western blot analysis using recombinant DcEV VP1 polypeptide showed a high seroprevalence of 52 % among serum samples from 172 dromedaries for IgG, concurring with its much higher infection rates in dromedary calves than in adults. Further studies are important to understand the pathogenicity, epidemiology and genetic evolution of DcEV in this unique group of animals.

The missing hump: a clarification on the reported two-humped stage in the embryonic development of the dromedary (Camelus dromedarius)

Early anatomical studies carried out on foetuses and adult dromedaries that were kept at San Rossore, Italy, revealed the presence of an atrophic second hump anterior to the single hump present in the dromedary leading to suggestions that the dromedary and the bactrian camel were a single species and the dromedary was simply a race of bactrian. However, a recent study on dromedary foetuses and calves failed to detect such structure. Historical data and photographic evidence of the dromedary herd of San Rossore suggest that the presence of such structure was caused by the introduction of hybrid dromedaries a common beast of burden in medieval Europe.

A re-description of Physocephalus dromedarii stat. nov. (Nematoda: Spirocercidae), an abomasal nematode of dromedaries (Camelus dromedarius)

Physocephalus dromedarii stat. nov. was found in the abomasum of two adult female dromedaries originating from a farm in Dubai. Previously, this nematode has been misidentified as a subspecies of Ph. sexalatus but morphological differences are striking enough for it to be upgraded to a species. Physocephalus dromedarii is larger than Ph. sexalatus and has longer spicules. There are 20-22 oblique crests at the ventral surface between the caudal alae of the male compared to 7-8 in the case of Ph. sexalatus. The most significant differences are the presence of two pairs of papillae between cloaca and postcloacal plate of the male and the existence of a swelling in the second half of the female body formed by loops of both uterine horns.

Normal Radiographic and Ultrasonographic Appearance of the Adult Dromedary Camel Tarsus (One Humped Camel)

Six cadaver pelvic limbs were obtained from clinically sound dromedary camels and examined radiographically and ultrasonographically using a 7.5 MHz convex transducer. Radiographic examination was performed in dorsoplantar, lateromedial, dorsolateral-plantaromedial oblique and plantarolateral-dorsomedial oblique projections, and the bony structures and articulations of the tarsal joint were outlined. The tarsus was ultrasonographically investigated in four planes (dorsal, medial, lateral and plantar), and each plane was scrutinized in four levels (calcaneal tuber, tibial malleoli, base of calcaneus and proximal end of metatarsus) in both transverse and longitudinal views. Limbs were examined grossly, frozen at -20°C and sectioned. Radiographic and ultrasonographic findings correlated well with the gross anatomy and frozen sections. The normal appearance of bony and soft structures of the tarsus described in this study provided basic reference data for ultrasonographic and radiographic investigations of tarsal disorders in the dromedary camel.

BOVINE VIRAL DIARRHEA-AN EMERGING DISEASE IN CAMELIDS A REVIEW

Bovine Viral Diarrhea (BVD) is an emerging disease in both New World Camelids (NWCs) and Old World Camelids (OWCs). The virus has been isolated from NWCs particularly in alpacas and dromedaries, but there are no reports of BVD in Bactrians. BVD is an important infectious disease. Both sub-genotypes 1a, 1b and genotype 2 have been isolated from NWCs but the ncp BVDV 1b is primarily implicated in cases of BVD in NWCs. A BVD strain unique to camelids has not yet been isolated. In NWCs virtually all infections have been caused by the non-cytopathic (ncp) BVDV, Persistently infected crias have also been detected. Llamas and alpacas demonstrate clinical signs such as ill thrift, diarrhea, respiratory ailments and abortions. As in bovines, identification and elimination of PI animals, has the highest priority to avoid infection of the entire herd. BVD was also observed in dromedaries and interestingly, both genotypes of the Pestivirus, BVDV-1 and BVDV-2, were isolated from dromedaries in Egypt. Both isolates revealed a cytopathic effect (cpe) and so far no ncp virus has been isolated from dromedaries. Also in dromedaries, BVD infections caused intrauterine death, stillbirth, weak calf syndrome with congenital deformities, neonatal respiratory disorders in young dromedary calves and acute hemorrhagic gastroenteritis in adult dromedaries. So far, no PI dromedaries have been described.

Is There a Two-Humped Stage in the Embryonic Development of the Dromedary?

It has been postulated that the one-humped (Arabian) dromedary and the two-humped (Bactrian) camel originated from a single ancestor. Consequently, the dromedary was considered a breed of the two-humped camel, based on an anatomical study by Lombardini L, 1879: Ann. Del. Universita Toscane, 259, 147, who described a reduced second hump like structure in foetal and adult dromedaries. To resolve this lingering issue, we analysed dromedary foetuses and calves. In contrast to the situation in two-humped camels, we never observed any rudimentary second hump in the dromedary foetuses or calves.

Sedative and analgesic effects of romifidine in camels (Camelus dromedarius)

ObjectiveTo evaluate the clinical effectiveness and the sedative and analgesic effects of intravenous (IV) romifidine in camels. Study designRandomized prospective study. AnimalsEighteen healthy adult Dromedary camels. MethodsRomifidine was administered IV to camels (n = 6) at three different doses (40, 80 or 120 μg kg−1). Time of onset, degree and duration of sedation and analgesia were recorded immediately after drug administration. Heart rate, respiratory rate, ruminal contractions, muscle relaxation, response to auditory and tactile stimulation, distance between ears, distance from lower lip to the ground, and degree of ataxia were also recorded pre-administration and at 5, 15, 30, 45, 60, 90, 120 and 180 minutes post-administration. Plasma glucose, blood urea nitrogen and creatinine were measured. ResultsRomifidine produced dose dependent sedation and analgesia. Significant decreases in heart rate (p < 0.001), ruminal contractions (p < 0.05), distance from lower lip to the ground (p < 0.001), response to auditory and tactile stimuli (p < 0.01), and significant increases in the degree of ataxia (p < 0.01), distance between the ear tips (p < 0.001) and blood glucose (p < 0.01) concentration were recorded after administration of romifidine until recovery. However, no significant changes in rectal temperature and respiratory rate were recorded. Conclusions and clinical relevanceIntravenous administration of romifidine at three different doses appeared to be an effective sedative and analgesic agent for camels. Bradycardia, ruminal atony, and hyperglycemia were the most important adverse effects after IV administration of romifidine. The IV administration of romifidine at a dose rate of 120 μg kg−1 caused profound sedation and analgesia. Romifidine could be used for chemical restraint for a variety of diagnostic and minor surgical procedures in camels.

Encapsulated sensory receptors within intraorbital skeletal muscles of a camel.

The occurrence of encapsulated sensory receptors in extrinsic ocular muscles differs among and within orders of mammals. Beyond indications that neuromuscular and neurotendinous spindles are present in extraocular muscles of the family Camilidae, little is known of their distributional characteristics. In fact there appear to be no distribution maps for any animal that show both major types of encapsulated muscle receptor in a full set of intraorbital skeletal muscles. Serial histological sections of all skeletal muscles from one orbit of an adult, one-humped camel (Camelus dromedarius) were examined for encapsulated receptors. Encapsulated receptors were apparent in all the intraorbital skeletal muscles. Muscle spindles outnumbered tendon organs in the fleshy part of each muscle. For all muscles, spindles were most abundant in the half of the muscle near the origin; levator palpebrae superioris had a more even distribution of spindles along its length than did extraocular muscles. These longitudinal patterns of distribution for muscle spindles related in a general way to the nerve entry zone. Tendon organs occurred anywhere along a muscle's length, but they tended to be more frequent on either side of the major concentration of muscle spindles. Both types of encapsulated receptors were generally located nearer the perimeter than the center of cross sections through muscles. Encapsulated receptors of classic appearance are plentiful and have distinctive configurations within intraorbital skeletal muscles of the adult dromedary. When analyzed in conjunction with other studies, the present data give rise to testable explanations for the variability among genera in the number of encapsulated receptors in extraocular muscles.

Lumbosacral plexus of the dromedary (Camelus dromedarius). I. Descriptive anatomy of the cranial portion

In this work, we have used 12 adult dromedaries of both sexes, aged between 2 and 12 years. The nerves were traced in the fresh state with the aid of a binocular dissecting microscope. The lumbosacral plexus was compared with that of the horse, other ruminants, pig, and carnivores. The origin, course, and distribution of the various branches of the cranial part of the plexus are described in detail. The lumbosacral plexus of the dromedary was found to be almost identical to that of the horse; some similarities with cattle were observed.

Nonselective Angiocardiography in the Cat

Middle East Respiratory Syndrome (MERS) is a zoonotic viral disease that can be transmitted from dromedaries to human beings. More than 1500 cases of MERS have been reported in human beings to date. Although MERS has been associated with 30% case fatality in human beings, MERS coronavirus (MERS-CoV) infection in dromedaries is usually asymptomatic. In rare cases, dromedaries may develop mild respiratory signs. No MERS-CoV or antibodies against the virus have been detected in camelids other than dromedaries. MERS-CoV is mainly acquired in dromedaries when they are less than 1 year of age, and the proportion of seropositivity increases with age to a seroprevalence of 100% in adult dromedaries. Laboratory diagnosis of MERS-CoV infection in dromedaries can be achieved through virus isolation using Vero cells, RNA detection by real-time quantitative reverse transcriptase-PCR and antigen detection using respiratory specimens or serum. Rapid nucleocapsid antigen detection using a lateral flow platform allows efficient screening of dromedaries carrying MERS-CoV. In addition to MERS-CoV, which is a lineage C virus in the Betacoronavirus (betaCoV) genus, a lineage B betaCoV and a virus in the Alphacoronavirus (alphaCoV) genus have been detected in dromedaries. Dromedary CoV UAE-HKU23 is closely related to human CoV OC43, whereas the alphaCoV has not been detected in human beings to date.