2002 Onderstepoort Journal of Veterinary Research, Volume 69, 2002

Permanent URI for this collectionhttp://hdl.handle.net/2263/17806

Contents Pages: Onderstepoort Journal of Veterinary Research, Vol 62, 1995

CONTENTS

*Volume 69: Number 1*

Seasonal abundance of adult ixodid ticks infesting cattle belonging to resource-limited farmers in the north-eastern Free State Province of South Africa	Hlatshwayo, M, Mbati, PA & Dipeolu, OO	1

Redescription of some Spauligodon spp. and Parapharyngodon spp., and of Skrjabinodon mabuyae (Sandground, 1936) Inglis, 1968 (Pharyngodonidae: Oxyuroidea) from insectivorous South African lizards	Boomker, JDF, Hering-Hagenbeck, SFBN & Petter, AJ	7

Redescription of some Thelandros and Tachygonetria spp. (Pharyngodonidae: Oxyuroidea) from the omnivorous plated lizard, Gerrhosaurus validus validus A. Smith, 1849 in South Africa	Boomker, JDF, Hering-Hagenbeck, SFBN & Petter, AJ	31

Description of Pelonia africana n. g., n. sp. (Pentastomida: Sebekidae) from the lungs of Pelomedusa subrufa and Pelusios sinuatus (Chelonia) in South Africa	Boomker, JDF & Junker, K	53

Validation of an indirect enzyme-linked immunosorbent assay for the detection of antibody against Brucella abortus in cattle sera using an automated ELISA workstation	Paweska, JT, Prozesky, L, Potts, AD, Harris, HJ, Smith, SJ, Viljoen, GJ, Dungu, B, Brett, OL & Bubb, M	61

The classification of seven serotypes of equine encephalosis virus and the prevalence of homologous antibody in horses in South Africa	Howell, PG, Bosman, AM, Coetzer, JAW, Guthrie, AJ, Groenewald, D & Visage, CW	79

Research communication:

Teratogenicity of a mutagenised Rift Valley fever virus (MVP 12) in sheep	Hunter, P, Erasmus, BJ & Vorster, JH	95


*Volume 69: Number 2*

Acaricide resistance profiles of single- and multi-host ticks from communal and commercial farming areas in the Eastern Cape and North-West Provinces of South Africa	Horak, IG, Mekonnen, S, Bryson, NR, Fourie, LJ, Peter, RJ, Spickett, AM, Taylor, RJ & Strydom, T	99

Parasitological prevalence of bovine trypanosomosis in Kindo Koisha district, Wollaita zone, south Ethiopia	Kidanemariam, A, Hadgu, K & Sahle, M	107

Seasonal abundance of four Culicoides spp. (Diptera: Ceratopogonidae) at Al-Ahsa oasis, Eastern Province, Saudi Arabia	Abu Elzein, EME, Hilali, M, Al-Afaleq, AI, Mellor, PS, Boorman, J, Al-Atiya, S & Al-Naiem, A	115

An overview of the eradication of Brucella melitensis from KwaZulu-Natal	Emslie, FR & Nel, JR	123

Isolation of serovar C-3 Haemophilus paragallinarum from Zimbabwe: a further indication of the need for the production of vaccines against infectious coryza containing local isolates of H. paragallinarum	Bragg, RR	129

Occurrence of concurrent trypanosomosis, theileriosis, anaplasmosis and helminthosis in Friesian, Zebu and Sahiwal cattle in Uganda	Magona, JW & Mayende, JSP	133

Seasonal availability of gastrointestinal nematode larvae to cattle on pasture in the central highlands of Kenya	Waruiru, RM, Weda, EH, Otieno, RO & Ngotho, JW	141

The Kumm isolate of Ehrlichia ruminantium: in vitro isolation, propagation and characterization	Zweygarth, E, Van Heerden, H, Allsopp, BA, Josemans, AI, Van Strijp, MF & Allsopp, MTEP	147

Non-immune control of trypanosomosis: in vitro oxidative burst of PMA- and trypanosome-stimulated neutrophils of Boran and N'Dama cattle	Taiwo, VO, Adejinmi, JO & Oluwaniyi, JO	155

Virulence of South African isolates of Haemophilus paragallinarum. Part 1: NAD-dependent field isolates	Bragg, RR	163

Virulence of South African isolates of Haemophilus paragallinarum. Part 2: Naturally occurring NAD-independent field isolates	Bragg, RR	171


*Volume 69: Number 3*

Hosts, seasonal occurrence and life cycle of Rhipicentor nuttalli (Acari: Ixodidae)	Horak, IG, Fourie, LJ, Kok, DJ & Van Zyl, W	177

Virulence of South African isolates of Haemophilus paragallinarum. Part 3: Experimentally produced NAD-independent isolate	Taole, M, Albertyn, J, Van Heerden, E & Bragg, RR	189

In vitro isolation of equine piroplasms derived from Cape Mountain zebra ( Equus zebra zebra) in South Africa	Zweygarth, E, Meyer, P & Lopez-Rebollar, LM	197

Multiplication of the V4 strain of Newcastle disease virus in Madin Derby bovine kidney cells	Sahle, M, Burgess, WG & Kidanemariam, A	201

Hepatic and renal concentrations of copper and other trace elements in hippopotami (Hippopotamus amphibius L.) living in and adjacent to the Kafue and Luangwa Rivers in Zambia	Mwase, M, Almli, B, Sivertsen, T, Musonda, MM & Flaoyen, A	207

A survey on the occurrence of resistance to anthelmintics of gastrointestinal nematodes of goats in Mozambique	Boomker, JDF, Atanasio, A & Sitoe, C	215

The gamma-interferon test: its usefulness in a bovine tuberculosis survey in African buffaloes ( Syncerus caffer) in the Kruger National Park	Michel, AL, Grobler, DG, De Klerk, LM & Bengis, RG	221

Strategic control of gastrointestinal nematodes of sheep in the highlands of central Kenya	Maingi, N, Otieno, RO, Gichohi, VM & Weda, EH	229

Development of solid phase antigen for indirect ELISA for the detection of specific antibody responses to infection with Newcastle disease virus	Sahle, M & Burgess, GW	237

The effect of three bufadienolide cardiac glycosides on contraction of isolated rat jejunum	Botha, CJ, Gehring, R, Van Rooyen, JM & Venter, D	243

Development of a diagnostic one-tube RT-PCR for the detection of Rift Valley fever virus	Nel, LH, Espach, A, Romito, M & Viljoen, GJ	247

Book reviews:

Infectious diseases of wildlife : detection, diagnosis and management. Revue Scientifique et Technique		253

Quarantine and health screening protocols for wildlife prior to translocation and release into the wild		254


*Volume 69: Number 4*

The prevalence and economic importance of bovine fasciolosis in Kenya - an analysis of abattoir data	Kithuka, JM, Maingi, N, Njeruh, FM & Ombui, JN	255

Animal-level risk factors for Trypanosoma evansi infection in camels in eastern and central parts of Kenya	Ngaira, JM, Bett, B & Karanja, SM	263

On-host ecology and off-host survival of the sheep scab mite Psoroptes ovis	Horak, IG, Meintjes, T & Fourie, LJ	273

Effects of the scab mite Psoroptes ovis on the haematology and live mass of Merino and Dorper sheep	Horak, IG, Meintjes, T & Fourie, LJ	285

Apparent prevalence of dourine in the Khomas region of Namibia	Kumba, FF, Claasen, B & Petrus, P	295

Freezing of sheep faeces invalidates Haemonchus contortus faecal egg counts by the McMaster technique	Van Wyk, JA & Van Wyk, L	299

Review of current problems and shortcomings in the Tanzanian animal health information system with suggestions on improvement	Kivaria, FM & Kapaga, AM	305

Water absorption in relation to fermentation in the colon of the ostrich (Struthio camelus)	Musara, C, Chamunorwa, JP, Holtug, K & Skadhauge, E	315

Continuous exposure to an aversive mixture as a means of maintaining aversion to vermeerbos (Geigeria ornativa O. Hoffm.) in the presence of non-averted sheep	Snyman, LD, Schultz, RA, Kellerman, TS & Labuschagne, L	321

Research communication:

Amphistome infection of goats farmed under resource-poor conditions in South Africa	Vatta, AF & Krecek, RC	327

Author index		331

Subject index		341

Browse

Now showing 1 - 20 of 43

Development of a diagnostic one-tube RT-PCR for the detection of Rift Valley fever virus
(Published jointly by the Agricultural Research Council, ARC-Onderstepoort Veterinary Institute and the Faculty of Veterinary Science, University of Pretoria., 2002) Espach, Anel; Romito, M.; Viljoen, G.J.; Boomker, Jacob Diederik Frederik; Nel, Louis Hendrik
Diagnosis of Rift Valley fever (RVF) is based on serology and virus isolation. The disadvantages of the former include poor sensitivity, high cost, risks associated with using infectious virus as antigen, the lengthy duration of ELISA as well as cross-reactivity with other Phleboviruses. We developed, optimised and evaluated a one-tube reverse-transcription-polymerase chain reaction (RT-PCR) for the detection of Rift Valley fever virus (RVFV) in ruminants. The PCR primers for this assay were designed to anneal to a region within the M segment of the virus genome, encoding glycoproteins G1 and G2. A PCR amplicon of 363 bp was obtained. The sensitivity of the assay was determined to be 0.25 TCID₅₀. This test should allow for the early and rapid detection of RVFV in both serum and whole blood. In addition, it could facilitate the quantification of antigen for the manufacture of current vaccines.
The effect of three bufadienolide cardiac glycosides on contraction of isolated rat jejunum
(Published jointly by the Agricultural Research Council, ARC-Onderstepoort Veterinary Institute and the Faculty of Veterinary Science, University of Pretoria., 2002) Botha, C.J. (Christoffel Jacobus); Gehring, Ronette; Van Rooyen, J.M.; Venter, D.; Boomker, Jacob Diederik Frederik
Three cardiac glycosides were screened for pharmacological effects on isolated rat jejunum. The contraction of rat jejunum with epoxyscillirosidin, a non-cumulative bufadienolide, and cotyledoside and tyledoside D, both cumulative neurotoxic bufadienolides were compared with methacholine. The results indicate that all three bufadienolides cause contraction of jejunal smooth muscle. When combined with atropine (1X10ˉ⁶ M) the response of epoxyscillirosidin and tyledoside D decreased, indicating suppression of a cholinergic response caused by the cardiac glycosides.
Water absorption in relation to fermentation in the colon of the ostrich (Struthio camelus)
(Published jointly by the Agricultural Research Council, ARC-Onderstepoort Veterinary Institute and the Faculty of Veterinary Science, University of Pretoria., 2002) Musara, C.; Chamunorwa, Joseph Panashe; Holtug, K.; Skadhauge, E.; Boomker, Jacob Diederik Frederik
The colon is a major site for fermentation and water absorption in the ostrich. Water absorption along the colon was evaluated and its relationship to osmolality, Na+ concentration, short chain fatty acid (SCFA) concentration and carbohydrate content of digesta analysed. Mean water content decreased from 5.30±0.99 to 2.51±0.13 ml/g dry mass in the first 5 m of the colon. Correspondingly, mean carbohydrate content fell from 529.85±46.61 to 434.99±29.89 mg/g dry mass. A significant correlation was shown between the decreases in mean carbohydrate and water content along the colon (r²=0.997, P<0.05). Changes in mean osmolality (±10 mOsm/kg) and SCFA concentration (±7 mmol/l) were minimal in comparison to the change in Na+ concentration (-54 mmol/l). These findings reflect a close coupling between SCFA production and absorption on the one hand and water absorption on the other.
The Kumm isolate of Ehrlichia ruminantium: in vitro isolation, propagation and characterization
(Published jointly by the Agricultural Research Council, ARC-Onderstepoort Veterinary Institute and the Faculty of Veterinary Science, University of Pretoria., 2002) Josemans, A.I.; Van Strijp, M.F.; Allsopp, M.T.E.P.; Boomker, Jacob Diederik Frederik; Zweygarth, Erich; Van Heerden, Henriette; Allsopp, Basil A.
An effective culture system for Ehrlichia (Cowdria) ruminantium comb. nov. was first established in 1985 and many stocks were subsequently isolated and propagated in vitro. A notable exception, however, was the Kumm isolate that resisted all attempts at in vitro culture until the successful experiment described here. In one experiment white blood cells were harvested from heparinized blood derived from a sheep infected with the Kumm isolate. The cells were added to DH 82 cells and incubated at 37degreesC. The high metabolic activity of the DH 82 cells necessitated that cell growth be retarded by the addition of cycloheximide. Colonies were first detected 19 days after culture initiation and, once the cultures were established, they could be passaged every 3 days. Bovine and sheep endothelial cells were readily infected with culture supernatant obtained from the infected DH 82 cells. In a further experiment, another sheep was infected, using a higher dose of the same batch of Kumm stabilate, and we attempted to infect several different cell lines: these were DH 82 cells, bovine aorta (BA 886) cells, sheep brain endothelial (SBE 189) cells and sheep fibroblastoid cells (E₂). Ten days after culture initiation, only the E₂ cells had become positive for E. ruminantium. Culture supernatant from the first cultured isolate (Kumm-1) was less virulent for mice than that of the second cultured isolate (Kumm-2) which killed all mice. Upon molecular characterization with E. ruminantium 16S probes, we found that Kumm-1 hybridized with a Senegal 16S genotype probe, whereas Kumm-2 hybridized only with an Omatjenne 16S genotype probe. The original stabilate used to infect the sheep hybridized with both probes. These results clearly indicate that two different stocks had been isolated in culture.
Non-immune control of trypanosomosis: in vitro oxidative burst of PMA- and trypanosome-stimulated neutrophils of Boran and N'Dama cattle
(Published jointly by the Agricultural Research Council, ARC-Onderstepoort Veterinary Institute and the Faculty of Veterinary Science, University of Pretoria., 2002) Taiwo, V.O.; Adejinmi, J.O.; Oluwaniyi, J.O.; Boomker, Jacob Diederik Frederik
An in vitro assay that measures the generation of superoxide anions (O₂ˉ) was used to assess the level of oxidative burst of phorbol myristate acetate (PMA) - and trypanosome-stimulated neutrophils isolated from healthy Boran and N'Dama cattle, and those infected with Trypanosoma congolense. PMA stimulation of healthy bovine neutrophils resulted in between 300-400% increase in O₂ˉ generation. Neutrophils of Boran cattle exhibited slightly higher, but insignificant O₂ˉ generation capacity than those of the N'Dama breed. In vitro stimulation by trypanosomes of neutrophils isolated from Trypanosoma congolense-infected cattle caused significant increases in O₂ˉ generation, especially on days 14, 28 and 42 post-infection, of both breeds of cattle. No significant differences were observed in O₂ˉ generation capacity of the neutrophils of both breeds of infected cattle throughout the period of assay. The results of this study have shown that PMA and trypanosomes do cause an enhanced in vitro oxidative burst, hence trypanosome phagocytosis and killing activity of neutrophils. Neutrophils have been shown to play very significant roles in parasite clearance, hence reduction of trypanosome parasitaemia. The rates of both in vitro generation of O₂ˉ and trypanosome phagocytosis over time did not differ significantly between Boran and N'Dama breeds of cattle, even during T. congolense infection in this study. Hence, it may be inferred that sustained and higher parasitaemia, more pronounced neutropenia, inadequate bone marrow response and less effective trypanosome-specific immune response, rather than defective neutrophil trypanosome destruction, may be the problem of trypanosusceptible cattle breeds.
Subject index
(Published jointly by the Agricultural Research Council, ARC-Onderstepoort Veterinary Institute and the Faculty of Veterinary Science, University of Pretoria., 2002) Anonymous; Boomker, Jacob Diederik Frederik
Author index
(Published jointly by the Agricultural Research Council, ARC-Onderstepoort Veterinary Institute and the Faculty of Veterinary Science, University of Pretoria., 2002) Anonymous; Boomker, Jacob Diederik Frederik
Review of current problems and shortcomings in the Tanzanian animal health information system with suggestions on improvement
(Published jointly by the Agricultural Research Council, ARC-Onderstepoort Veterinary Institute and the Faculty of Veterinary Science, University of Pretoria., 2002) Kivaria, F.M.; Kapaga, A.M.; Boomker, Jacob Diederik Frederik
Livestock diseases have always been the focus of the Tanzanian Veterinary Authorities. However, they have become more important since the formation of the World Trade Organisation and subsequent implementation of the various multilateral agreements on trade. There is also a strong political desire to improve the animal health status as part of poverty alleviation strategies. As a result there is a need to develop better systems for investigating and reporting of animal diseases. In order to follow the OIE pathway and to obtain a disease free status, reliable evidence of freedom from particular diseases is becoming an issue of major interest. Assessment of the Tanzanian animal health information system revealed two major problems; firstly, the absence of disease information that accurately reflects the health status of the source population, and secondly, an inefficient information management system which is unable to provide useful information on the spatial component of animal health. A strategic approach is proposed that involves the collection of animal health information using active surveillance techniques and the introduction of a geographic information system. This approach should improve the management and reporting of animal health information.
Description of Pelonia africana n. g., n. sp. (Pentastomida: Sebekidae) from the lungs of Pelomedusa subrufa and Pelusios sinuatus (Chelonia) in South Africa
(Published jointly by the Agricultural Research Council, ARC-Onderstepoort Veterinary Institute and the Faculty of Veterinary Science, University of Pretoria., 2002) Junker, Kerstin; Boomker, Jacob Diederik Frederik; Boomker, Jacob Diederik Frederik
The terrapins Pelomedusa subrufa and Pelusios sinuatus taken from a water reservoir in the Northern Province, South Africa, were examined for pentastome infections. Two immature specimens, a patent female and a mature male, were obtained from the lungs of four hosts, each of which harboured a single specimen. Based on the morphology of the specimens the new monospecific genus, Pelonia africana n. g., n. sp., is described. It is characterized by smooth, dorsally convex hooks with sharply bent blades. The oral cadre is more or less U-shaped. Delicate chitinous fibres, which can be difficult to see, connect the lateral prongs anteriorly. In this, as well as the morphology of the copulatory spicules, it is most like Sebekia wedli. The latter, however, possesses spinous hooks, which are absent in P. africana. The hooks are slightly and the copulatory spicules markedly larger in P. africana than in S. wedli. The lack of a double-hooked collar at the terminal end of the cowry-shell shaped base of each copulatory spicule and the absence of a peg-like extension of the oral cadre into the oesophagus, distinguishes P. africana from members of the genus Alofia. The oral cadre of the South American species Diesingia megastoma, from aquatic chelonians, is more than twice the size than that of Pelonia and there is a distinct difference in shape. The hooks of the genus Diesingia are flat-topped and both the anterior as well as the posterior fulcra carry cowl-like extensions. The number of annuli, 55-60 in D. megastoma and approximately 30 in P. africana, further separates the two genera. The most striking feature of Diesingia which sets it apart from Pelonia and the other genera of the family Sebekidae is the configuration of its copulatory spicules. Pelonia and Diesingia share morphological features with all the other sebekiids but it is the unique combination of diagnostic characters that separates the two genera from those, as well as from each other.
Teratogenicity of a mutagenised Rift Valley fever virus (MVP 12) in sheep
(Published jointly by the Agricultural Research Council, ARC-Onderstepoort Veterinary Institute and the Faculty of Veterinary Science, University of Pretoria., 2002) Hunter, P.; Erasmus, B.J.; Vorster, J.H. (Jan Harm); Boomker, Jacob Diederik Frederik
A 5-fluorouracil mutagenised Rift Valley fever virus strain, which was shown to be attenuated and immunogenic in cattle and sheep, was evaluated for its ability to cause teratogenic effects in pregnant sheep. A group of 50 sheep at various stages of pregnancy was inoculated with the virus and the pregnancies followed to term. There were two abortions and 14% of the lambs produced by vaccinated ewes showed teratogenic effects, the most prevalent being spinal hypoplasia, hydranencephaly, brachygnathia inferior and arthrygryposis. The foetal malformations of the central nervous and musculo-skeletal systems were mostly consistent with those observed in sheep vaccinated with the attenuated Smithburn RVF strain. The teratogenic effects of MVP12 were not seen in previous experiments by other authors as immunisation of sheep took place in the second to third trimester of pregnancy, when the fetal brain tissue has completed most of its cell division.
Amphistome infection of goats farmed under resource-poor conditions in South Africa
(Published jointly by the Agricultural Research Council, ARC-Onderstepoort Veterinary Institute and the Faculty of Veterinary Science, University of Pretoria., 2002) Vatta, A.F.; Krecek, R.C.; Boomker, Jacob Diederik Frederik
From December 1998 to April 2000, a longitudinal study was conducted of the pooled trematode faecal egg counts of samples collected from goats of resource-poor farmers at Rust de Winter, Gauteng Province, Impendle, KwaZulu-Natal Province, and Kraaipan, North-West Province, South Africa. The amphistome faecal egg counts followed a seasonal pattern, with an increase in the counts during the warmer months of the year (October to March). This is the first work concerning the seasonal cycling of amphistomes in ruminants in South Africa.
Continuous exposure to an aversive mixture as a means of maintaining aversion to vermeerbos (Geigeria ornativa O. Hoffm.) in the presence of non-averted sheep
(Published jointly by the Agricultural Research Council, ARC-Onderstepoort Veterinary Institute and the Faculty of Veterinary Science, University of Pretoria., 2002) Snyman, Leendert D.; Schultz, R.A. (Rowena Anitra); Kellerman, T. Stephanus; Labuschagne, Leonie; Boomker, Jacob Diederik Frederik
Continuous exposure to an aversive mixture was investigated as a means of maintaining aversion to vermeerbos in sheep subjected to the social influence of non-averted sheep. The use of an aversive mixture was based on a hypothesis that continuous exposure to an acceptable aversive mixture (containing both the aversive substance and the identification factors of vermeerbos mixed with maize meal) would tempt sheep to consume small quantities of the aversive mixture each day and that this would keep them averted to vermeerbos, despite the social influence of non-averted sheep. Persistent aversion to a vermeerbos-maize meal mixture (1:99 by mass) by sheep continuously exposed to such an aversive mixture, after an initial aversion conditioning with lithium chloride (LiCl, 160 mg/kg BM), was demonstrated. Aversion in adjacent controls not exposed to the aversive mixture only lasted for some time. A similar result was obtained when sheep were challenged for intake of a pure stand of established vermeerbos. Three sheep continuously exposed to an aversive mixture after an initial aversion conditioning totally refused grazing the vermeerbos during a 42-day trial, despite the social influence of three non-averted control sheep grazing vermeerbos on an adjacent site. These results were confirmed by a second replication the following year. Joint grazing for an hour a day by averted and non-averted sheep during the last seven days of this replication also resulted in total avoidance of vermeerbos by the averted animals, despite continued intake of vermeerbos by the control sheep.
Multiplication of the V4 strain of Newcastle disease virus in Madin Derby bovine kidney cells
(Published jointly by the Agricultural Research Council, ARC-Onderstepoort Veterinary Institute and the Faculty of Veterinary Science, University of Pretoria., 2002) Sahle, M.; Burgess, W.G.; Kidanemariam, Awoke; Boomker, Jacob Diederik Frederik
This study describes a reproducible cell culture system that permits the growth and secondary multiplication of the V4 strain of Newcastle disease virus. Allantoic fluid, magnesium chloride and diethylaminoethyl dextran were incorporated in Dulbecco's modified Eagle's medium to encourage secondary viral multiplication without adversely affecting healthy Madin Derby bovine kidney cell growth.
The classification of seven serotypes of equine encephalosis virus and the prevalence of homologous antibody in horses in South Africa
(Published jointly by the Agricultural Research Council, ARC-Onderstepoort Veterinary Institute and the Faculty of Veterinary Science, University of Pretoria., 2002) Groenewald, Daleen; Visage, Carina W.; Boomker, Jacob Diederik Frederik; Howell, P.G.; Bosman, Anna-Mari; Coetzer, Jacobus A.W.; Guthrie, Alan John
Selected isolates of equine encephalosis virus were shown to have comparable viral protein profiles and to represent seven distinct serotypes, based on cross-neutralization tests. Serotype-specific virus-neutralizing antibody in serum samples from horses confirmed the widespread occurrence of infection. The distribution and prevalence of individual serotypes however, varied considerably. Localised foci with an increased seasonal seroconversion in groups of horses to a specific serotype and the detection of an ongoing low level of infection from other serotypes within the population, confirmed the independent persistence of the viruses in a maintenance cycle. The identification of donors with antibody resulting from infection with multiple serotypes indicated a low level of cross protection in horses to natural reinfection.
Apparent prevalence of dourine in the Khomas region of Namibia
(Published jointly by the Agricultural Research Council, ARC-Onderstepoort Veterinary Institute and the Faculty of Veterinary Science, University of Pretoria., 2002) Kumba, F.F.; Claasen, B.; Petrus, P.; Boomker, Jacob Diederik Frederik
A 15-year record of the results of horse sera from the Khomas region of Namibia tested by the complement fixation test for dourine at the Central Veterinary Laboratory in Windhoek before clearing the respective animals for export and competitive sport were subjected to statistical analysis. The range of percentage positive, taken as the apparent prevalence of dourine for the region, during the period of study, was 0-29.09%; the average regional level of apparent prevalence was 8.33%. These figures were thought to be lower than the real situation due to some bias in the sampling criteria. For more accurate results, the more reliable enzyme-linked immunosorbent assay techniques are recommended for use in sero-surveys for dourine in Khomas and other regions of Namibia to provide a basis for development of effective control strategies against the disease.
Book review
(Published jointly by the Agricultural Research Council, ARC-Onderstepoort Veterinary Institute and the Faculty of Veterinary Science, University of Pretoria., 2002) Anonymous; Boomker, Jacob Diederik Frederik
Book review
(Published jointly by the Agricultural Research Council, ARC-Onderstepoort Veterinary Institute and the Faculty of Veterinary Science, University of Pretoria., 2002) Anonymous; Boomker, Jacob Diederik Frederik
The prevalence and economic importance of bovine fasciolosis in Kenya - an analysis of abattoir data
(Published jointly by the Agricultural Research Council, ARC-Onderstepoort Veterinary Institute and the Faculty of Veterinary Science, University of Pretoria., 2002) Kithuka, J.M.; Maingi, N.; Njeruh, F.M.; Ombui, J.N.; Boomker, Jacob Diederik Frederik
A retrospective study covering a period of 10 years (1990-1999) was carried out using post mortem meat inspection records at the Veterinary Department Headquarters at Kabete to determine the prevalence and economic importance of bovine fasciolosis in Kenya. Meat inspection records from abattoirs in 38 districts distributed over seven out of the eight provinces of Kenya were examined. Prevalence of fasciolosis was calculated as the number of cattle found to be infected with Fasciola, expressed as a percentage of the total number of cattle slaughtered. Using the average weight and market price of a bovine liver, the monetary loss occasioned by condemnation of Fasciola infected livers was calculated. A survey was also carried out at Dagoretti slaughterhouse complex in Nairobi to determine the relative occurrence of F. gigantica and F. hepatica in slaughtered cattle. Cattle slaughtered at Dagoretti slaughterhouse originate from all parts of the country. A total of 5 421 188 cattle were slaughtered in the seven provinces of Kenya during the 10-year period and 427 931 (8%) of these cattle were infected with Fasciola. The region with the highest prevalence of fasciolosis was Western Province (16%) followed, in descending order, by Eastern Province (11%), Nyanza Province (9%), Rift Valley Province (8%), Central Province (6%), Nairobi Province (4%) and Coast Province (3.5%). The total economic loss incurred by the country during the 10-year period as a result of condemnation of the infected livers was approximately US$2.6 million. The total annual economic losses during this period ranged from approximately US$0.2-0.3 million. The highest total economic losses for the 10-year period were recorded in Western Province (US$0.8 million) and Central Province (US$0.7 million). A total of 1 584 cattle originating from five provinces of Kenya were slaughtered at Dagoretti slaughterhouse over a period of two months of which 147 (9.3%) were infected with liver flukes. All the liver flukes obtained from the infected livers were identified as F. gigantica. It is concluded that fasciolosis is prevalent in cattle in all provinces of Kenya, that it causes great economic losses as a result of condemnation of infected livers, and that F. gigantica is the main species of liver flukes affecting cattle in Kenya. Local climatic factors, cattle trade, rustling and population numbers, and the presence of the snail intermediate hosts are probably the main factors influencing the incidence of the disease in the various regions of the country.
An overview of the eradication of Brucella melitensis from KwaZulu-Natal
(Published jointly by the Agricultural Research Council, ARC-Onderstepoort Veterinary Institute and the Faculty of Veterinary Science, University of Pretoria., 2002) Emslie, Forbes Richard; Nel, J.R.; Boomker, Jacob Diederik Frederik
Brucella melitensis is a Gram-negative bacterium whose primary hosts are goats and sheep. Like the other Brucella spp., with the exception of Brucella ovis, it is not particularly host specific as it is pathogenic for a variety of other mammal species including humans. In humans the disease caused by it is rated as one of the most important zoonoses. Three outbreaks have been recorded in goats and sheep in South Africa; the first outbreak occurred in sheep in 1965 in the Mpumalanga and Northern Provinces (then both part of the Transvaal Province), the second occurred in sheep in 1989 near Pretoria, Gauteng Province, and the third and current outbreak was diagnosed in a flock of goats in northern KwaZulu-Natal in September 1994. Following the initial diagnosis of B. melitensis in north-eastern KwaZulu-Natal, a serological survey was conducted in order to identify foci of infection in the goat and sheep populations. Six positive foci were identified. In March 1996 a test-and-slaughter eradication campaign was initiated in these areas. Initial test results revealed a prevalence of between 1.23% and 4.02%. All positive animals were identified and slaughtered. Eradication programmes were repeated between March 1996 and June 2000, in the populations at risk, and the disease prevalence was reduced in all the affected populations.
Effects of the scab mite Psoroptes ovis on the haematology and live mass of Merino and Dorper sheep
(Pretoria : Agricultural Research Council, ARC-Onderstepoort Veterinary Institute and the Faculty of Veterinary Science, University of Pretoria., 2002) Meintjes, T.; Fourie, L.J.; Boomker, Jacob Diederik Frederik; Horak, Ivan Gerard
Five Merino and five Dorper sheep were artificially infested with the sheep scab mite Psoroptes ovis and the effect of infestation on their haematology, serum protein levels and live mass recorded for a period of 14 weeks. The reaction of the Merino sheep to infestation was more severe than that of the Dorper sheep. Haematological values fluctuated within the normal range during the assessment period. The mean haemoglobin concentration of the Merino sheep declined until antiparasitic treatment was administered 10 weeks after infestation, after which it gradually increased. The lymphocyte counts of both breeds of sheep declined from 2 weeks to 10 weeks post-infestation, but increased after treatment, while the highest eosinophil counts were recorded in the Merino sheep at the height of the acute disease 8-10 weeks post-infestation. Serum albumin values for both breeds and serum globulin values for the Merino sheep were higher than normal during the entire 14-week observation period. A decrease in serum albumin and an increase in serum globulin concentration occurred at the height of infestation in both breeds. The mean live mass of a second group of five infested Merino sheep decreased by 6.4 kg over a 16-week period compared to a gain of 4.56 kg for five infested Dorper sheep.

Browse

Recent Submissions