Anatomy of the Sinus Node of Camels (Camelus dromedarius)

Anatomy of the sinus node was studied in six camel hearts (Camelus dromedarius) with serial histologic sectioning. The sinus node in this species of animal was located 0.5 mm beneath the epicardium, near the junction between the cranial vena cava and the right atrium at the sulcus terminalis. Its shape was elongated, bent oblong with 28.25 mm length, 5.75 mm width and 5.38 mm thickness. The maximum section area was 101.66 mm². The central artery of the node originated from the circumflexus branch of the left coronary artery and, throughout its length in the substance of the sinus node, had an internai elastic membrane. Histologically, the sinus node of this animal contained a central artery and a framework of collagen fibres, which were distributed around the central artery. The nodal cells were irregularly organized around the central artery and two types, i.e.‘p’ cells and transitional cells were present. The ‘p’ cells had a perinuclear clear zone but the transitional cells contained more myofibrils. The intercalated dises were not present. At the periphery of the sinus node there were many nerve fibres and a ganglion. The purkinje fibres were present within atrial myocardium, as well as within ventricular myocardium. The glycogen content of the sinus nodal cells was higher than that of the atrial myocardial cells.     

Some Endotoxin-induced Clinical and Biochemical Changes in Plasma of Camels (Camelus dromedarius)

Intravenous administration of endotoxin, prepared from E. coli serotype O55:B5, at a dose of 0.1 microg/kg body weight to calves and adult camels induced fever and increased haematocrit, triiodothyronine and cortisol values. The endotoxin-treated animals showed significantly decreased (p < 0.05) total protein, urea, glucose and creatinine. A significant increase was seen in the activity of aspartate aminotransaminase and creatine kinase. These results demonstrate high sensitivity of camels to endotoxin.     

The Zinc and Copper Content of the Plasma of Sudanese Camels (Camelus dromedarius)

A study was undertaken to investigate the variations in the content of zinc and copper in the plasma of Sudanese camels (Camelus dromedarius). A total of 993 Arabi camels, aged 0.5-8 years, were used to assess the effect of season, age, sex and physiological status on the plasma concentrations of copper and zinc. There was an increase in the concentration of Cu and a decrease in the concentration of Zn in the plasma with age. The concentrations of both Cu and Zn in the plasma were higher in the rainy season than in the dry season. The plasma copper concentrations in pregnant, low-lactating and high-lactating camels were 81.3 +/- 4.7, 59.7 +/- 6.1 and 61.3 +/- 5.5 microg/100 ml, respectively. The corresponding values for zinc were 51.0 +/- 8.9, 53.4 +/- 6.4 and 67.1 +/- 5.5 microg/100 ml, respectively. However, there was no effect of sex on the content of these minerals in the plasma.     

Observations on the Clinical Examination of the Camel (Camelus dromedarius) in the Field

Camels usually inhabit remote areas, where diagnostic facilities and laboratories are very scarce. The species differences between the camel and other domestic animals necessitate some specific examination techniques. The objective of this study was to describe the clinical examination methods and sources of common errors that require special consideration in the camel. Young camels are examined in the standing position, while adults require restraint. Restraining procedures, both standing and in sternal recumbency, are described. New equipment and a crush were designed. The body temperature of the camels examined fluctuated from 35.7 to 38.9 degrees C, being lowest in the morning and highest in the afternoon; high temperature in the morning is indicative of fever, while high afternoon temperatures could be hyperthermia. It was difficult to take the pulse rate for routine procedures. The heart rate ranged from 35 to 50 per min; there was no difference between the heart rate in the morning and in the afternoon. The mean respiratory rate was 11 per min and respiration was of thoracol-lumbar type. The mucous membranes of the eye were an important site for appreciating signs of discoloration, while those of the mouth, rectum and vagina were unsuitable. The left flank was the best site for determining the rate of rumen contractions, which was 3+/-1.2 every 5 min, as determined by auscultation; counting the contractions by the application of the fist was difficult. The palpable external lymph nodes were the parotid, maxillary, prescapular, inferior cervical, thoracic, cubital, ilial and popiteal; they are large and can be seen on inspection in healthy animals, so that was not indicative of disease. A list of diagnostic indicators for the rapid diagnosis of ten endemic camel diseases was generated from the empirical signs.     

Serosurvey of Coxiella burnetii (Q fever) in Dromedary Camels (Camelus dromedarius) in Laikipia County,Kenya

Dromedary camels (Camelus dromedarius) are an important protein source for people in semi‐arid and arid regions of Africa. In Kenya, camel populations have grown dramatically in the past few decades resulting in the potential for increased disease transmission between humans and camels. An estimated four million Kenyans drink unpasteurized camel milk, which poses a disease risk. We evaluated the seroprevalence of a significant zoonotic pathogen, Coxiella burnetii (Q fever), among 334 camels from nine herds in Laikipia County, Kenya. Serum testing revealed 18.6% positive seroprevalence of Coxiella burnetii (n = 344). Increasing camel age was positively associated with C. burnetii seroprevalence (OR = 5.36). Our study confirmed that camels living in Laikipia County, Kenya, have been exposed to the zoonotic pathogen, C. burnetii. Further research to evaluate the role of camels in disease transmission to other livestock, wildlife and humans in Kenya should be conducted.     

Prevalence of Faecal Pathogens in Calves of Racing Camels (Camelus dromedarius) in the United Arab Emirates

Tropical Animal Health and Production -     

Studies on Cephalopina titillator,the Cause of 'Sengale' in Camels (Camelus dromedarius) in Semi-arid Areas of Somali State,Ethiopia

The overall prevalence rate of Cephalopina titillator in 778 slaughtered camels was 71.7%, 55% in males and 85% in females. The mean larval counts in infested camels were 26.7±25.9 and 34.6±30.8, for males and females, respectively. There were highly significant differences (p<0.001) in the number of larvae in camels of different ages and sexes and also between the wet and dry seasons. The average time to pupate was 4.9±4.6 minutes, and the pupation period was 21±2.4 days. The major gross lesions observed were congestion of the pharyngeal mucosa with profuse secretions, and haemorrhage in early cases. In some cases, there were ulcer-like lesions and nodules, which contained pus. The dominant microscopic lesions were infiltration of the lamina propria by eosinophils, lymphocytes and macrophages, hyperplasia of the stratified squamous epithelium, necrotic changes in the mixed glands and desquamation of epithelial cells. A survey using questionnaires revealed that all the camel owners called the disease caused by infestation with C. titillator `Sengale' and that 87% of them considered that infestation with these larvae results in reduced milk production and body weight. The major clinical signs of the disease were sneezing and expulsion of larvae (68%), abnormal movement of the head (45%), grooming (44%), nasal discharge (40%), poor appetite (26.7%), difficulty in breathing (18%), and sometimes bleeding from the nostrils (18%) and coughing (27%).     

The Male Genital Tract of the Dromedry (One-Humped) Camel (Camelus dromedarius): Gross and Microscopic Anatomy

The anatomy of the male genital system of 6 prepubertal, 6 pubertal and 6 mature dromedary camels is described. Developmental and comparative aspects of the male reproductive system are discussed. Histologic examination demonstrated the development of spermatogenic and accessory glandular tissues     

The Poll Glands of the Dromedary (Camelus dromedarius): Ultrastructural Characteristics

The poll glands of the camel are tubuloalveolar glands. They consist of lobules separated by interlobular connective tissue. Adrenergic axons and blood vessels including fenestrated capillaries are present in the intralobular connective tissue in close proximity to the secretory cells. The prominent features of the secretory cell cytoplasm are many mitochondria, smooth endoplasmic reticulum, and many vesicles in various secretory stages.
It is concluded that the secretory cells have apocrine as well as merocrine modes of secretion. The glands may have the ability to uptake hormones and concentrate them. Additional work is needed before considering these glands as steroid-secreting glands.     

Demonstration of 16-Unsaturated C-19 Steroids ('Boar Pheromones') in Tissues of the Male Camel (Camelus dromedarius)

Contents
Investigations into the role of pheromones in reproductive behaviour have been mainly limited to the boar, with 16-unsaturated C-19 steroids playing a major role. Similarities in the mating behaviour of the camel and pig suggest that pheromones may also be important in the camel. The aim of this study was to determine the concentrations of 16-unsaturated steroids in camel testes and other tissues. Samples of testicular tissue were obtained by castration from six male camels (9–15 years) and 16-unsaturated steroid content was measured by gas–liquid chromatography (GLC). In addition, samples of the glandula occipitalis ('poll gland'), g. parotis, g. submandibularis and the palatal flap ('dulaa') were obtained from a 10-year-old camel and also analysed for steroid content. Results were confirmed by GC-MS (gas-chromatography-mass spectrometry) in selected testicular samples. 5α-androst-16-en-3-one could be detected in all testicular specimen (range 0.05–1.28  μ g/g tissue) as well as in all the other tissues analysed, with highest concentrations in the glandula occipitalis. 5α-androst-16-en-3β-ol was present in most tissues, whereas 5α-androst-16-en-3α-ol was detectable at 0.75  μ g/g only in one testes which also had the highest level of 5α-androst-16-en-3-one. The similarities of these findings to the porcine species suggest a role of 16-unsaturated steroids as pheromones in the camel. Further experimental evidence however, is required to confirm these findings.     

A quantitative study of the circulus arteriosus cerebri of the camel (Camelus dromedarius)

The afferent vessels of the circulus arteriosus cerebri in the camel were studied quantitatively. It was found that the diameters of the arteries did not differ significantly on the left and right sides. An interesting observation was that the basilar artery contributed to the blood supply of the brain in the camel, in contrast to the situation in other ruminants.     

The parotid, mandibular and lateral retropharyngeal lymph nodes of the camel (Camelus dromedarius)

The parotid, mandibular and lateral retropharyngeal lymph nodes of the dromedary camel were examined using both light and electron microscopy. All three lymph nodes were lobulated. They did not show the characteristic medulla, cortex and paracortex of typical lymph nodes. Instead, they contained lymphatic nodules, dense anodular lymphoid tissue and diffuse lymphoid tissue dispersed throughout the lymph node. Networks of sinuses were present in the diffuse lymphoid tissue. The diffuse lymphoid tissue in the periphery of all lymph nodes examined was characterized by numerous erythrocytes within and around its network of sinuses. The nodal sinuses were contiguous with the septal vessels, which are considered the possible source of erythrocytes seen in this study. The lymph nodes that were seen in this study resembled the haemolymph nodes of other mammals with regard to their content of erythrocytes but were unique in being located in sites that were typical of ordinary lymph nodes. Morphometric analysis has shown that the percentage volume densities of the stroma and the various parenchymal components were similar in the three lymph nodes.     

Morphological,morphometric and histochemical characterization of the gastric mucosa of the camel (Camelus dromedarius)

Mucosal morphology, morphometry and mucin histochemistry of the stomach were studied in the one-humped camel. The lining of the stomach was divided into eight grossly identifiable regions. The first region was non-glandular, occupied the body of the first compartment of the stomach and constituted 53.2% of the gastric mucosa. The other seven regions were lined by a glandular mucosa. Histological, histochemical and morphometric investigations have shown that glandular mucosa comprises pseudo-cardiac, cardiac, fundic and pyloric regions. The pseudo-cardiac region was characterized by widely separated short tubular serous glands. It constituted 36.2% of the gastric mucosa; it extended over the entire lining of the second compartment and parts of the first and third compartments. The cardiac region was confined to the initial zone of the third compartment amidst the psuedo-cardiac region but contiguous with the distal end of the gastric groove. It constituted 3.4% of the gastric mucosa and was characterized by neutral and acid mucin positive glands. The fundic and pyloric regions occupied the distal distended part of the third compartment. The fundic region constituted 4.3% of the gastric mucosa. It was packed with typical fundic glands characterized by chief cells, parietal cells and acid mucin positive neck cells. The pyloric region constituted 2.9% of the gastric mucosa. Its glands were positive to acid mucins except for their bases that were positive to neutral mucins. Differences in volume densities of the mucosal components and reactivity of the surface epithelium and gastric pits to mucin stains were noted in the different regions of the stomach.     

Ultrastructural analysis of the integument of a desert-adapted mammal, the one-humped camel (Camelus dromedarius)

In this study, we conducted a light microscopic and ultrastructural analysis of the integument of the one-humped camel (Camelus dromedarius). In general, the epidermal strata of the camel integument appeared typical of those found in non-desert mammals. Two cell populations were noted in the stratum basale: one with a flat, non-serrated base and the other with a highly serrated base. Typical fine structure was observed in keratinocytes of the stratum spinosum and stratum granulosum. The stratum corneum was six to 10 cells thick. Within the different strata, overall cell morphologies and the general distribution and relative abundance of cellular organelles appeared typical. Dermal features included the presence of myoepithelial cells surrounding apocrine tubular glands. Inter- or intracellular canaliculi within the secretory cells of the apocrine glands, reported to be present in certain other non-desert mammals, were not evident in the camel. Together, these data indicate that while the camel is clearly adapted for a desert lifestyle, these adaptations do not include significant specializations at the cellular or subcellular level in the integument.     

Evaluation of sexual behavior of housed male camels (Camelus dromedarius) through female parades: correlation with climatic parameters

Camels are seasonal breeders, and their sexual behavior is influenced by environmental conditions, but the relationship between climatic factors and sexual behavior has been poorly described in the available literature. Nowadays, the male camel living habit is shifting towards captivity; thus, this study was carried out to evaluate the sexual behavior of housed male dromedary camel through female’s parades and to correlate it with climatic parameters. Four housed sires, reared for semen collection, and one dam were used and the trial lasted 8 weeks, considering the first week as control. Six days per week and during evenings, the female was brought near each males’ boxes, while two observers filled a behavioral sampling ethogram and scored the male sexual behavior. After this parade, blood samples were taken from the female to evaluate the estradiol concentration. In addition, the following meteorological parameters were recorded, everyday, at 9:00 a.m. and 19:00 p.m.: pressure, wind, temperature, humidity, and H-index. The correlation between sexual behavioral score and female estradiol concentration and climate parameters was analyzed. All the behavioral parameters showed a significant upward trend; female estradiol concentration varied during the period and picked at week 5. Male sexual behavior was negatively correlated with morning H-index, wind, and temperature, and positively correlated with pressure and evening humidity, whereas it was not correlated with estrogen. In conclusion, female parade was a successful method to evaluate and stimulate the occurrence of housed male dromedary camel sexual activity that resulted to be negatively affected by hot temperature, warm wind, and lack of rain.