V de Vos

Publications of V de Vos

• Parasites of domestic and wild animals in South Africa. XLI. Arthropod parasites of impalas, Aepyceros melampus, in the Kruger National Park.

  Authors: I G Horak, G J Gallivan, L E O Braack, J Boomker, V de Vos

  The Onderstepoort journal of veterinary research. 07/2003; 70(2):131-63.

  Ectoparasites were collected from impalas, Aepyceros melampus, at four localities within the Kruger National Park, namely Skukuza, in the Biyamiti region, Crocodile Bridge and Pafuri. Animals wereEctoparasites were collected from impalas, Aepyceros melampus, at four localities within the Kruger National Park, namely Skukuza, in the Biyamiti region, Crocodile Bridge and Pafuri. Animals were also examined at Skukuza during a severe drought and at Skukuza and Pafuri towards the end of a second drought. Parasite burdens were analysed in relation to locality, sex, age class, month and drought. The impalas were infested with 13 ixodid ticks species, including two that were identified only to genus level. Except for four animals at Pafuri, all were infested with Amblyomma hebraeum. The highest intensity of infestation with larvae of this tick occurred from April to June and during November and December at Skukuza and in the Biyamiti region. Infestation with nymphs was highest during late winter. All animals were infested with Boophilus decoloratus, and the intensity of infestation was highest during spring. The intensity of infestation with Rhipicephalus appendiculatus was highest at Crocodile Bridge and at Pafuri, and that of Rhipicephalus zambeziensis at Skukuza. With both the latter species the intensity of infestation of larvae was highest from April to August, of nymphs from July to September or October and of adults during February and March. Rhipicephalus kochi was present only at Pafuri. The impalas also harboured five louse species and two species of hippoboscid flies. The intensity of infestation with lice tended to be greater during late winter and spring than during other seasons and greater on lambs than on yearlings on which it was greater than on adult animals.

• The epidemiology of tuberculosis in free-ranging African buffalo (Syncerus caffer) in the Kruger National Park, South Africa.

  Authors: V de Vos, R G Bengis, N P Kriek, A Michel, D F Keet, J P Raath, H F Huchzermeyer

  The Onderstepoort journal of veterinary research. 07/2001; 68(2):119-30.

  The presence of bovine tuberculosis (Mycobacterium bovis) in the Kruger National Park (KNP) was determined for the first time in 1990. It was diagnosed in an African buffalo (Syncerus caffer) bull,The presence of bovine tuberculosis (Mycobacterium bovis) in the Kruger National Park (KNP) was determined for the first time in 1990. It was diagnosed in an African buffalo (Syncerus caffer) bull, which was found recumbent and in an emaciated and moribund state near the south-western boundary fence. This prompted an investigation into the bovine tuberculosis (BTB) status of the KNP, with emphasis on its epidemiological determinants and risk factors. This report documents the findings of surveys that were conducted from 1990 to 1996. It was found that BTB had entered the KNP ecosystem relatively recently (+/- 1960), and has found favourable circumstances for survival and propagation in a fully susceptible and immunologically naive buffalo population. Indications are that it entered the KNP from across the southern river boundary, where the presence of infected domestic cattle herds had been documented. From there the infection spread through the southern buffalo population and is currently spreading in a northward direction. It was estimated that this northward spread took place at a rate of about 6 km per year; the prospect being that, if this rate of spread is maintained, the entire KNP may be affected in less than 30 years from now. Spillover from buffalo had already occurred in species such as chacma baboon (Papio ursinus), lion (Panthera leo), cheetah (Acinonyx jubatus), kudu (Tragelaphus strepsiceros) and leopard (Panthera pardus). Although there is no indication yet that these species act as maintenance hosts, the possibility is raised that these, or an as yet overlooked species, might assume such a role in future. In the KNP, BTB manifests itself as a chronic and predominantly subclinical disease in buffalo. It may take years for clinical signs to develop, and then only at a terminal stage, when emaciation is a constant feature. It is suspected that the time from infection to death is variable and dependent on the animal's immune response, which can be weakened by such factors as stress, old age or droughts. It was found that, in the interim, buffalo have a normal reproductive life. On necropsy, buffalo show almost exclusively lung and upper respiratory tract involvement, pointing to an aerogenous mode of transmission. Histologically, little sign of encapsulation of lesions was detected, which suggests that they are exceptionally susceptible to BTB and that most lesions are open and infectious and progressive, leading ultimately to death of the individual. Evidence also indicates that BTB is progressive within the herd context (92% being the highest prevalence rate thus far determined in a buffalo herd) as well as progressive within the KNP buffalo population (the implication being that virtually all buffalo herds in the KNP will eventually be infected). Preliminary data suggest a positive correlation between disease prevalence and mortality, with potential mortality reaching up to 10% in buffalo herds having BTB prevalence rates of 50 % and higher. Only the future will tell what the effect of the disease on the population dynamics of buffalo will be.

• Prevalence of bovine tuberculosis in African buffalo at Kruger National Park.

  Authors: T C Rodwell, N P Kriek, R G Bengis, I J Whyte, P C Viljoen, V de Vos, W M Boyce

  Journal of wildlife diseases. 04/2001; 37(2):258-64.

  Bovine tuberculosis (BTB) was first detected in Kruger National Park (KNP) in a single African buffalo (Syncerus caffer) in 1990. In 1991/1992, 2,071 African buffalo were examined for BTB as part ofBovine tuberculosis (BTB) was first detected in Kruger National Park (KNP) in a single African buffalo (Syncerus caffer) in 1990. In 1991/1992, 2,071 African buffalo were examined for BTB as part of a culling program that removed animals from all known herds in KNP. The prevalence of BTB in 1991/1992 was estimated to be 0%, 4.4% (+/-0.6%), and 27.1% (+/-1.4%), in the north, central, and south zones of KNP, respectively. In 1998, a stratified, two-stage cluster sampling method was used to estimate that the prevalence of BTB was 1.5% (+/-2.5%), 16% (+/-5.3%), and 38.2% (+/-6.3%), in the north, central, and south zones, respectively. This represented a significant increase in prevalence (P < or = 0.05) in the south and central zones, but not in the north zone. Continued monitoring of BTB in KNP is important for understanding disease transmission risks, potential population effects, and the efficacy of disease management strategies. The methodology and sample sizes used in 1998 are appropriate for future BTB monitoring in KNP.

• Distribution of endocrine cells in the gut of the impala (Aepyceros melampus).

  Authors: J H Schoeman, V De Vos, G Van Aswegen

  The Onderstepoort journal of veterinary research. 04/1998; 65(1):31-5.

  Immunocytochemical methods were employed to demonstrate endocrine cells, containing peptides and serotonin, in the gut of the impala. Cells immunoreactive to serotonin, somatostatin, gastrin,Immunocytochemical methods were employed to demonstrate endocrine cells, containing peptides and serotonin, in the gut of the impala. Cells immunoreactive to serotonin, somatostatin, gastrin, cholecystokinin, glucagon, neurotensin, secretin, glucose-dependent insulinotropic peptide and motilin were detected. Antisera raised to substance P and pancreatic polypeptide failed to stain any cells. The distribution of these peptide-containing cells is more in line with the situation in sheep than other ruminants. In contrast, the distribution and abundance of serotonin cells in the gut of the impala parallels the situation seen in game herbivores.

• Detection of AHV-1 DNA in lung sections from blue wildebeest (Connochaetes taurinus) calves by in situ hybridization.

  Authors: A L Michel, J J van der Lugt, R G Bengis, V de Vos

  The Onderstepoort journal of veterinary research. 10/1997; 64(3):235-8.

  In situ hybridization was performed on formalin-fixed, paraffin-embedded lung sections from eight blue wildebeest (Connochaetes taurinus) calves to investigate the role of this organ in the excretionIn situ hybridization was performed on formalin-fixed, paraffin-embedded lung sections from eight blue wildebeest (Connochaetes taurinus) calves to investigate the role of this organ in the excretion of alcelaphine herpes virus-1 (AHV-1). A digoxigenin labelled Smal fragment of AHV-1 was used as a DNA probe. Viral DNA was detected in the lungs of seven calves in which infection with AHV-1 had previously been confirmed, indicating the significance of the lower respiratory tract in viral replication and excretion. The results also confirmed the sensitivity of the in situ hybridization technique in detecting low amounts of viral DNA in infected cells in routinely processed tissues.

• Wildlife parasites: lessons for parasite control in livestock.

  Authors: F S Malan, I G Horak, V de Vos, J A Van Wyk

  Veterinary parasitology. 08/1997; 71(2-3):137-53.

  For sustainable livestock production it is suggested that the parasitologist take a leaf out of Nature's book in the search for solutions to the mounting problems concerning parasite control. WhileFor sustainable livestock production it is suggested that the parasitologist take a leaf out of Nature's book in the search for solutions to the mounting problems concerning parasite control. While the farmer has come to regard all parasites affecting livestock as entirely without benefit, indigenous parasites and diseases are normal and play an essential role as interacting components of a natural environment in an ecosystem such as the 19,000 km2-sized Kruger National Park, Republic of South Africa. The parasites help to select their hosts for fitness and are assisted by predators and intra-species territorial aggression which continually eliminate the weak individuals from the system. It is essential to guard against the introduction of foreign parasites or infectious agents which have no real ecological niche or role in an established ecosystem, however, as they cause untoward interactions, sometimes of a violent nature. The policy must be to block off or, failing that, to control or eliminate these foreign parasites and diseases as far as possible. Often, when Man intervenes in an ecosystem, it leads to stress, overcrowding and stagnation and predisposes to disease and death. Intensification of the system, as in farming units, denies Nature the chance to manage on its own, because of clashing interests with Man. Frank parasitism and disease should almost invariably be seen as indicators of an imbalance in the ecosystem and should be rectified. Chemicals and vaccines should be used to produce sufficient food for all, but without exploiting Nature, or else Nature will be unable to continue catering for Man's needs.

• The intestine and endocrine pancreas of the African elephant: a histological immunocytochemical and immunofluorescence study.

  Authors: G Van Aswegen, S Van Noorden, S H Kotze, V De Vos, J H Schoeman

  The Onderstepoort journal of veterinary research. 01/1997; 63(4):335-40.

  Histological, immunocytochemical and immunofluorescence methods were employed to study the intestine and endocrine pancreas of the elephant. The histological findings were in line with those inHistological, immunocytochemical and immunofluorescence methods were employed to study the intestine and endocrine pancreas of the elephant. The histological findings were in line with those in monogastric mammals. In the mucosa of intestine, endocrine cells were immunoreactive to somatostatin, gastrin, CCK, GIP, secretin, motilin, glucagon and NPY. Nerve cells immunoreactive to somatostatin, substance P, VIP, PHI, NPY, bombesin and CGRP were detected. No immunoreactivity to neurotensin was observed, islets of the pancreas had insulin cells in their cores and glucagon and somatostatin cells in their mantles. The antisera employed failed to demonstrate PP cells in the pancreas, but NPY-immunoreactive cells were present.

• An outbreak of bovine tuberculosis in a free-living African buffalo (Syncerus caffer--sparrman) population in the Kruger National Park: a preliminary report.

  Authors: R G Bengis, N P Kriek, D F Keet, J P Raath, V de Vos, H F Huchzermeyer

  The Onderstepoort journal of veterinary research. 04/1996; 63(1):15-8.

  Bovine tuberculosis was diagnosed for the first time in an African buffalo (Syncerus caffer) in the Kruger National Park (KNP). The index case was a 2-year-old, emaciated bull which had been foundBovine tuberculosis was diagnosed for the first time in an African buffalo (Syncerus caffer) in the Kruger National Park (KNP). The index case was a 2-year-old, emaciated bull which had been found recumbent and obviously ill, near the south-western boundary of the KNP, in July 1990. During a follow-up random sampling of 57 buffalo, from two herds in close proximity to this initial case, nine more suspect cases were found. Mycobacterium bovis was isolated from a lung and thoracic lymph node, respectively, of two of these cases. Histopathologically, all nine of these animals had granulomatous lesions compatible with a diagnosis of mycobacteriosis, but acid-fast organisms could be demonstrated in only one animal.

• Morphology of the deciduous tusk (tush) of the African elephant (Loxodonta africana).

  Authors: E J Raubenheimer, W F van Heerden, P J van Niekerk, V de Vos, M J Turner

  Archives of oral biology. 07/1995; 40(6):571-6.

  The tusk of the African elephant is preceded by a deciduous tooth generally known as the tush. Tushes from nine elephant fetuses and six calves younger than 1 year were exposed by dissection andThe tusk of the African elephant is preceded by a deciduous tooth generally known as the tush. Tushes from nine elephant fetuses and six calves younger than 1 year were exposed by dissection and described morphologically. All tushes consisted of a crown, root and pulpal cavity, the formation of which is completed soon after birth. They reached a maximum length of 5 cm, appeared not to erupt through the skin and were pushed aside and resorbed during enlargement of the distally located primordium of the tusk. Dental enamel, which covered the crown, could easily be removed and consisted of rods with an interwoven arrangement; the dentine-enamel junction was flat. Cellular cementum extended for variable distances over the crown and the dentine was tubular in nature. Although the tush apparently has no function, it provides the anlage and orientation for the development of its permanent successor.

• The oesophagus and stomach of the African elephant: a histological, immunocytochemical and immunofluorescence study.

  Authors: G Van Aswegen, J H Schoeman, V De Vos, S Van Noorden

  The Onderstepoort journal of veterinary research. 10/1994; 61(3):223-9.

  Histological, immunocytochemical and immunofluorescence methods were employed to study the oesophagus and stomach of the elephant. The histological findings were in line with the situation inHistological, immunocytochemical and immunofluorescence methods were employed to study the oesophagus and stomach of the elephant. The histological findings were in line with the situation in monogastric species like swine and man. In the mucosa of the stomach, endocrine cells were immunoreactive to gastrin, somatostatin, chromogranin A and serotonin. Nerve cells immunoreactive to somatostatin, bombesin, VIP, PHI and CGRP were detected in the submucosal and myenteric plexus of the stomach. In the stomach, the absence of glucagon cells and the presence of endocrine cells immunoreactive to PYY, are in contrast to the situation in mammals and need further investigation. Small gastric ulcers were observed in some of the specimens.

• Parasites of domestic and wild animals in South Africa. XXX. Ectoparasites of kudus in the eastern Transvaal Lowveld and the eastern Cape Province.

  Authors: I G Horak, J Boomker, A M Spickett, V de Vos

  The Onderstepoort journal of veterinary research. 01/1993; 59(4):259-73.

  Sets of four kudus were shot and examined for arthropod parasites at approximately monthly intervals from April 1981 to March 1983 in the southern part of the Kruger National Park, eastern TransvaalSets of four kudus were shot and examined for arthropod parasites at approximately monthly intervals from April 1981 to March 1983 in the southern part of the Kruger National Park, eastern Transvaal Lowveld. These animals harboured 10 ixodid tick species of which Boophilus decoloratus followed by Amblyomma hebraeum were the most abundant. The seasonal abundances of these ticks and of Amblyomma marmoreum, Rhipicephalus appendiculatus, Rhipicephalus evertsi evertsi and Rhipicephalus zambeziensis were determined. The kudus were also infested with 3 lice and 1 louse fly species, as well as the nymphs of a pentastomid. Sixteen kudus were shot in the Andries Vosloo Kudu Reserve, eastern Cape Province and 9 on an adjacent farm. These animals were infested with 12 tick species. A. hebraeum followed by Rhipicephalus glabroscutatum were the most abundant on kudus in the reserve and R. glabroscutatum followed by Haemaphysalis silacea on the animals on the farm. The seasonal abundances of A. hebraeum, A. marmoreum, H. silacea, R. appendiculatus, R. glabroscutatum and a Rhipicephalus sp. (near R. oculatus) were determined on the kudus in the reserve. The kudus were also infested with 3 lice and 1 louse fly species. Two kudus examined in the Addo Elephant National Park were infested with 6 tick, 1 louse and 1 louse fly species.

• The response of animals to suxamethonium (succinyldicholine) and succinylmonocholine.

  Authors: J Hattingh, N I Pitts, V de Vos, D G Moyes, M F Ganhao

  Journal of the South African Veterinary Association. 10/1991; 62(3):126-9.

  The time which elapses before cessation of breathing, and blood pressure and blood gas changes after the intramuscular administration of suxamethonium, or a mixture of suxamethonium andThe time which elapses before cessation of breathing, and blood pressure and blood gas changes after the intramuscular administration of suxamethonium, or a mixture of suxamethonium and hexamethonium, is compared in immobilised African elephants (Loxodonta africana) and buffaloes (Syncerus caffer). In addition, the respiratory responses of elephants and other animals to intravenous administration of suxamethonium and succinylmonocholine are reported on, as are the effects of darting animals with succinylmonocholine. The results show that respiration is affected in a similar fashion in all species investigated. However, the characteristic gradual decrease in respiratory rate seen in elephants during culling, using suxamethonium, resembles the effects observed when succinylmonocholine is administered. It is suggested that elephants are killed by this first breakdown product of suxamethonium during culling and/or that unique acetylcholine receptors may be involved.

• Blood constituent responses of animals culled with succinyldicholine and hexamethonium.

  Authors: J Hattingh, N I Pitts, M F Ganhao, D G Moyes, V de Vos

  Journal of the South African Veterinary Association. 10/1990; 61(3):117-8.

  Blood constituent responses of elephants and buffaloes culled in the Kruger National Park, using a mixture of succinyldicholine and hexamethonium, were compared to those of animals culled withBlood constituent responses of elephants and buffaloes culled in the Kruger National Park, using a mixture of succinyldicholine and hexamethonium, were compared to those of animals culled with succinyldicholine only. The results show a decreased physiological response in the animals culled with the mixture, characterised by lower total catecholamine, cortisol and glucose concentrations. Neither a delay of up to 30 min in obtaining blood samples from culled animals, nor a delay of up to 30 min in processing samples obtained immediately after cessation of respiration, gave any significant difference in the blood constituents which were measured.

• Parasites of South African wildlife. IV. Helminths of kudu, Tragelaphus strepsiceros, in the Kruger National Park.

  Authors: J Boomker, I G Horak, V de Vos

  The Onderstepoort journal of veterinary research. 07/1989; 56(2):111-21.

  During ongoing surveys of parasites of wild animals in the Kruger National Park, a total of 96 kudu. Tragelaphus strepsiceros, were culled in the southern part of the park at monthly intervals fromDuring ongoing surveys of parasites of wild animals in the Kruger National Park, a total of 96 kudu. Tragelaphus strepsiceros, were culled in the southern part of the park at monthly intervals from April 1981 to March 1983. A single kudu was shot in the same area in November 1983. Two more kudu were obtained from Pafuri in the northern part of the Park during October 1981 and another from near Satara in the central part of the Park during October 1982. The helminths of all the kudu were collected and 2 trematode, 4 cestode and 18 nematode species recovered. Amongst the helminths recovered, Agriostomum gorgonis, Cooperia fuelleborni, Cooperia hungi, Cooperia yoshidai, Impalaia tuberculata, a Parabronema sp., a Setaria sp., Strongyloides papillosus, Trichostrongylus falculatus, Schistosoma mattheei, an Avitellina sp., Moniezia benedeni, and Echinococcus sp. larvae appear to be new records for kudu. Haemonchus vegliai, which has been considered a rare nematode, was present in many animals. An amended list of the parasites of kudu is included, and the seasonal abundance of the major nematode species discussed and graphically illustrated.

• Excretion of alcelaphine herpesvirus-1 by captive and free-living wildebeest (Connochaetes taurinus).

  Authors: B J Barnard, R G Bengis, M D Griessel, V de Vos

  The Onderstepoort journal of veterinary research. 07/1989; 56(2):131-4.

  Excretion of alcelaphine herpesvirus-1 (AHV-1) is for all practical purposes limited to wildebeest calves under the age of 4 months. Sixty-one per cent of calves 1-2 months of age excreted virus withExcretion of alcelaphine herpesvirus-1 (AHV-1) is for all practical purposes limited to wildebeest calves under the age of 4 months. Sixty-one per cent of calves 1-2 months of age excreted virus with a mean titre of 9.8 X 10(4) cytopathic-forming foci/ml in their ocular fluid. The incidence declined sharply to less than 2% in wildebeest older than 6 months. No difference in age-related excretion of virus could be detected between free-living and captive wildebeest and no virus could be isolated from free-living pregnant wildebeest cows or from captive cows and their calves during the first 4 weeks after birth. The occurrence of wildebeest-derived malignant catarrhal fever (WD MCF) during spring, when wildebeest do not excrete virus, is a strong indication of the existence of an alternative host or an intermediate host capable of biological transfer of AHV-1.

• Parotid salivary gland of the African elephant (Loxodonta africana): structure and composition of saliva.

  Authors: E J Raubenheimer, J Dauth, M J Dreyer, V de Vos

  Journal of the South African Veterinary Association. 01/1989; 59(4):184-7.

  Specimens from parotid salivary glands of full-grown elephant (Loxodonta africana) a (n=6) and saliva aspirated from their main excretory ducts were examined macroscopically and microscopically andSpecimens from parotid salivary glands of full-grown elephant (Loxodonta africana) a (n=6) and saliva aspirated from their main excretory ducts were examined macroscopically and microscopically and analyzed biochemically. The composition of the saliva was compared to that of the blood. The parotids (n=12; mean = 7.4 kg) are homocrine and of a seromucous nature. Myoepithelial cells are well-developed along intercalated ducts and their processes extend to proximal portions of allied acini. The saliva is hypotonic and contains relatively low concentrations of sodium and glucose and high concentrations of potassium, urea, calcium and phosphorus. Absence of detectable levels of alpha-amylase negates a digestive role and the voluminous secrete evidently aids swallowing by moisturising and lubricating the large mass of ingested leaves, grass and bark.

• Hepatic lesions associated with Cooperioides hepaticae (Nematoda: Trichostrongyloidea) infection in impala (Aepyceros melampus) of the Kruger National Park.

  Authors: J M Pletcher, I G Horak, V de Vos, J Boomker

  Journal of wildlife diseases. 11/1988; 24(4):650-5.

  Intrahepatic biliary lesions were observed in two of 12 lambs, seven of 12 yearlings and 10 of 25 adult impala (Aepyceros melampus) surveyed in the Kruger National Park, Republic of South Africa.Intrahepatic biliary lesions were observed in two of 12 lambs, seven of 12 yearlings and 10 of 25 adult impala (Aepyceros melampus) surveyed in the Kruger National Park, Republic of South Africa. Lesions were associated with the nematode Cooperioides hepaticae, a trichostrongyloid parasite that inhabits the bile ducts of impala, and ranged from a mild chronic-eosinophilic cholangitis to foci of florid hyperplastic cholangitis with duct ectasia. The latter almost always contained viable worms and, after the worms died, the lesions appeared as foreign-body granulomas. Infection was acquired early in life; severe lesions were seen most frequently in yearlings. Adults were less severely infected, which suggested an acquired immunity. Although the incidence of infection was high, cooperiiasis did not appear to be a serious herd-health problem at the time of this study.

• Blood lead concentrations in hippopotami (Hippopotamus amphibius) in the Kruger National Park.

  Authors: J Dauth, M J Dreyer, E J Raubenheimer, L B Lemmer, V de Vos

  Journal of the South African Veterinary Association. 10/1988; 59(3):153-4.

  Venous whole-blood samples for the determination of lead concentrations were obtained from hippopotami (Hippopotamus amphibius) (n = 26) during a population control programme on the banks of theVenous whole-blood samples for the determination of lead concentrations were obtained from hippopotami (Hippopotamus amphibius) (n = 26) during a population control programme on the banks of the Sabie River. A mean blood lead concentration of 26.3 micrograms l-1 was lower than the mean concentration of 34.0 micrograms l-1 cited for a group of young people living in a remote area where lead pollution was considered to be negligible. These concentrations indicate that lead pollution in this area of the Kruger National Park is at present low.

• Parasites of domestic and wild animals in South Africa. XXIII. Helminth and arthropod parasites of warthogs, Phacochoerus aethiopicus, in the eastern Transvaal Lowveld.

  Authors: I G Horak, J Boomker, V de Vos, F T Potgieter

  The Onderstepoort journal of veterinary research. 10/1988; 55(3):145-52.

  A total of 69 warthogs, Phacochoerus aethiopicus, were collected from 4 localities within the Kruger National Park, eastern Transvaal Lowveld. These animals harboured 16 nematode species, 2A total of 69 warthogs, Phacochoerus aethiopicus, were collected from 4 localities within the Kruger National Park, eastern Transvaal Lowveld. These animals harboured 16 nematode species, 2 trematodes, 1 or 2 species of adult cestodes and the larval stages of 4 cestodes. No pattern of seasonal abundance could be determined for any of the helminths. The warthogs were also infested with 3 flea species, 1 louse species, 8 ixodid tick species, 1 argasid tick and the nymphae of a pentastomid. The seasonal abundance of fleas of the genus Echidnophaga, of the sucking louse Haematopinus phacochoeri and the ixodid ticks Amblyomma hebraeum, Rhipicephalus appendiculatus, Rhipicephalus simus and Rhipicephalus zambeziensis was determined.

• Remote controlled sampling of cattle and buffalo blood.

  Authors: J Hattingh, M F Ganhao, F J Kruger, V de Vos, G W Kay

  Comparative biochemistry and physiology. A, Comparative physiology. 02/1988; 89(2):231-5.

  1. Blood samples were obtained from cattle and buffaloes over extended periods of time by remote controlled methods at 4-hourly intervals. 2. Initial handling of the animals and deliberate exposure1. Blood samples were obtained from cattle and buffaloes over extended periods of time by remote controlled methods at 4-hourly intervals. 2. Initial handling of the animals and deliberate exposure to stress at the end of the experimental times resulted in increased plasma concentrations of a number of variables. 3. Between initial handling and applied stress, the concentration of all variables investigated showed little change and no evidence of rhythms. 4. The results obtained reflect true plasma composition of free ranging cattle and buffaloes at rest.