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Species composition and geographic distribution of ticks infesting cattle, goats and dogs in a temperate and in a subtropical region of south-east Africa
2009
Horak, I.G.(University of Pretoria Faculty of Veterinary Science Department of Veterinary Tropical Diseases,University of the Free State Department of Zoology and Entomology) | Nyangiwe, N.(Döhne Agricultural Development Institute ,University of Pretoria Faculty of Veterinary Science Department of Veterinary Tropical Diseases) | De Matos, C.(Instituto de Investigação Agrária de Mozambique ,University of Pretoria Faculty of Veterinary Science Department of Veterinary Tropical Diseases) | Neves, L.(Universidade Eduardo Mondlane Faculdade de Veterinária)
The species and distribution of ticks infesting cattle, goats and dogs in the eastern region of the Eastern Cape Province, South Africa and Maputo Province, Mozambique were determined from collections made from these animals at 72 localities in the former region and 30 in the latter. Eleven ixodid and one argasid species were recovered in the Eastern Cape Province and 15 ixodid species in Maputo Province. The most common ticks infesting cattle and goats in both provinces were Amblyomma hebraeum, Rhipicephalus (Boophilus) microplus, Rhipicephalus appendiculatus and Rhipicephalus evertsi evertsi. The dominant species on dogs were Haemaphysalis elliptica and Rhipicephalus simus. The geographic distributions of the major species and some of the minor species in both regions were plotted. The partial or complete displacement of the indigenous tick Rhipicephalus (Boophilus) decoloratus by the introduced species R. (B.) microplus was a major feature of both surveys.
Show more [+] Less [-]Prevalence of bovine cysticercosis and hydatidosis in Jimma municipal abattoir, South West Ethiopia
2009
Tolosa, T.(Jimma University College of Agriculture and Veterinary Medicine School of Veterinary Medicine) | Tigre, W.(Jimma University College of Agriculture and Veterinary Medicine School of Veterinary Medicine) | Teka, G.(Jimma University College of Agriculture and Veterinary Medicine School of Veterinary Medicine) | Dorny, P.(Ghent University Faculty of Veterinary Medicine Laboratory of Parasitology,Institute of Tropical Medicine Department of Animal Health)
A cross-sectional study to determine the prevalence of bovine cysticercosis and hydatidosis was conducted from October 2007 to March 2008 in cattle slaughtered at the Jimma municipal abattoir. Cyst distribution and viability of bovine cysticercosis and hydatidosis were also determined. A total of 512 carcasses were inspected of which 15 (2.93%) and 161 (31.44%) were infected with Taenia saginata metacestodes and hydatid cysts, respectively. From a total of 109 cysticerci collected from infected carcasses, 47 (43.12 %) were viable. The anatomical distribution of the cysticerci was, shoulder muscle (39.5°%), heart (33.9 %), neck muscle (13.8°%), tongue (10.1°%), masseter muscles (1.8°%) and diaphragm (0.9°%). Of the 1171 hydatid cysts collected 223 (19.0°%) were fertile, 505 (43.1 °%) sterile, 49 (29.8 °%) calcified and 94 (8.0 °%) contained pus. A greater proportion of fertile cysts were found in the lungs than in other organs. It was concluded that these zoonotic cestodes deserve due attention to safeguard public health, and that further studies are needed on genotyping, epidemiology and public health importance of Echinococcus granulosus in the study area.
Show more [+] Less [-]Morphology of the tongue of the emu (Dromaius novaehollandiae). II. Histological features
2009
Crole, M.R.(University of Pretoria Faculty of Veterinary Science Department of Anatomy and Physiology) | Soley, J.T.(University of Pretoria Faculty of Veterinary Science Department of Anatomy and Physiology)
Although a number of brief, fragmented descriptions have been provided on the gross morphology of the ratite tongue, very few studies have documented the histological structure of this organ. This paper presents the first definitive histological description of the emu tongue and reviews, consolidates and compares the scattered information on the histology of the ratite tongue available in the literature. Five tongues were removed from heads obtained from birds at slaughter and fixed in 10 % neutral buffered formalin. Appropriate longitudinal and transverse segments were removed, routinely processed for light microscopy, and sections examined after staining with H & E and PAS. The entire tongue (body and root) is invested by a non-keratinized stratified squamous epithelium. The supporting connective tissue of the tongue dorsum displays only large, simple branched tubular mucus-secreting glands, whereas the caudal tongue body ventrum and tongue root, in addition to these glands, also exhibits small, simple tubular mucus-secreting glands. Herbst corpuscles are associated with the large, simple branched glands. Lymphoid tissue is restricted to the tongue ventrum and is particularly obvious at the junction of the ventral tongue body and frenulum where a large aggregation of diffuse lymphoid tissue, with nodular tissue proximally, was consistently observed. A structure resembling a taste bud was located in the epithelium on the caudal extremity of the tongue root of one bird. This is the first reported observation of taste buds in ratites. Forming the core of the tongue body is the cartilaginous paraglossum lying dorsal to the partially ossified rostral projection of the basihyale. The histological features of the emu tongue are generally similar to those described for the greater rhea and ostrich, except that taste buds were not identified in these species. The results would suggest that the emu tongue functions as a sensory organ, both for taste and touch (by virtue of taste receptors and Herbst corpuscles, respectively), as well as fulfilling an immunological function.
Show more [+] Less [-]A retrospective longitudinal study of animal and human rabies in Botswana 1989-2006
2009
Moagabo, K.T.(Botswana National Veterinary Laboratory) | Monyame, K.B.(Botswana National Veterinary Laboratory) | Baipoledi, E.K.(Botswana National Veterinary Laboratory) | Letshwenyo, M.(Department of Veterinary Services) | Mapitse, N.(Department of Veterinary Services) | Hyera, J.M.K.(Botswana National Veterinary Laboratory)
A longitudinal study of animal and human rabies covering 18 years from 1989 to 2006 was retrospectively conducted in order to highlight the epidemiological features and trends of the disease in Botswana. Over the 18-year period, a total of 4 306 brain specimens collected from various species of animals including human beings with clinical signs consistent with rabies were submitted to the National Veterinary Laboratory in Gaborone for confirmatory diagnosis. Of the samples submitted, 2 419 cases were found to be positive for lyssavirus antigen; this presents an overall prevalence rate of 56.18 ± 1.48 %. About 85.7 % (2 074/2 419) of the cases were from domestic animals, 14.2 % (343/2 419) cases were from wild animals and two cases (0.1 %) were from human beings. During the first half of the study (1989-1997) the prevalence rate of the disease was estimated at 62.79 ± 1.85 % (1 645/2 620 positive) whereas during the second half (1998-2006) it was estimated at 45.91 ± 2.38 % (774/1 686 positive) and the difference between the two estimates was statistically, highly significant (Δ % = 16.88, SE (95), diff % = 3.015, SD = 5.599; P< 0.001). Ruminant rabies accounted for 79.99 % (50.92 % bovine, 28.40 % caprine and 0.67 % ovine) whereas canine (domestic dog) and feline (domestic cat) accounted for 16.01 and 0.87 %, respectively. Equine rabies accounted for 3.13 % with 1.35 and 1.78 %, respectively, for horses and donkeys. Jackal rabies accounted for more than 60 % of the total cases in wild animals. These findings are discussed in relation to the previous epidemiological situation of the disease (1979-1988), its socio-economic impact, monitoring and control in Botswana.
Show more [+] Less [-]Responses of serum electrolytes of goats to twelve hours of road transportation during the hot-dry season in Nigeria, and the effect of pretreatment with ascorbic acid
2009
Ayo, J.O.(Ahmadu Bello University Faculty of Veterinary Medicine Department of Physiology and Pharmacology) | Minka, N.S.(Ahmadu Bello University College of Agriculture and Animal Science Division of Agricultural Colleges) | Sackey, A.K.B.(Ahmadu Bello University Faculty of Veterinary Medicine Department of Surgery and Medicine) | Adelaiye, A.B.(Ahmadu Bello University Faculty of Medicine Department of Physiology)
Twenty goats which served as the experimental group were administered ascorbic acid (AA) per os at a dosage rate of 100 mg/kg body mass, while 20 others served as controls and were given 10 ml each of sterile water. Forty minutes after the administration and loading, the goats were transported for 12 h. Handling and loading of the experimental and control groups of goats decreased (p< 0.05) the potassium and sodium serum concentrations. The concentration of serum chloride, sodium and calcium increased significantly (p< 0.05) immediately post-transportation, while potassium and magnesium decreased (p < 0.05) in the control goats. In AA-treated goats sodium and magnesium concentrations decreased abruptly (p< 0.05), while calcium increased significantly (p< 0.05) after transportation. Handling, loading and transportation adversely affected the electrolyte balance of the goats which suggested respiratory alkalosis, dehydration and muscular damage in the transported goats, and the administration of AA alleviated the adverse effects of road transportation stress on serum electrolytes.
Show more [+] Less [-]A brief history of botulism in South Africa
2009
Cameron, C.M.(South African Veterinary Association)
When looking back into the history of botulism and contemplating the final understanding of the syndrome and the ultimate solutions, there are four facets that stand out clearly. The first is that much of the solution was guided by astute observations, curious travellers, committed veterinarians and particularly farmers themselves who were able to relate the occurrence of the condition to climatic and grazing conditions. Secondly, there was the identification of the osteophagia and pica syndrome which led to the feeding of bone-meal as a successful mitigating measure as well as the establishment that botulism was not due to a plant poisoning. Thirdly, the solution of the problem depended on the integration of experience and knowledge from diverse disciplines such as soil science, animal behaviour and husbandry, nutrition, botany and ultimately advanced bacteriology and the science of immunology. Finally it required the technical advancement to produce toxoids in large quantities and formulate effective aluminium hydroxide precipitated and oil emulsion vaccines.
Show more [+] Less [-]Poisonous plants
2009
Kellerman, T.S.(University of Pretoria Faculty of Veterinary Science Section Pharmacology and Toxicology)
South Africa is blessed with one of the richest floras in the world, which-not surprisingly-includes many poisonous plants. Theiler in the founding years believed that plants could be involved in the aetiologies of many of the then unexplained conditions of stock, such as gousiekte and geeldikkop. His subsequent investigations of plant poisonings largely laid the foundation for the future Sections of Toxicology at the Institute and the Faculty of Veterinary Science (UP). The history of research into plant poisonings over the last 100 years is briefly outlined. Some examples of sustained research on important plant poisonings, such as cardiac glycoside poisoning and gousiekte, are given to illustrate our approach to the subject and the progress that has been made. The collation and transfer of information and the impact of plant poisonings on the livestock industry is discussed and possible avenues of future research are investigated.
Show more [+] Less [-]Persistence mechanisms in tick-borne diseases
2009
Barbet, A.F.(University of Florida College of Veterinary Medicine Department of Infectious Diseases & Pathology)
The use of new, highly sensitive diagnostic methods has revealed persistent infections to be a common feature of different tick-borne diseases, such as babesiosis, anaplasmosis and heartwater. Antigenic variation can contribute to disease persistence through the continual elaboration of new surface structures, and we know in several instances how this is achieved. Known or suspected mechanisms of persistence in babesial parasites include cytoadhesion and rapid variation of the adhesive ligand in Babesia bovis and genetic diversity in several merozoite stage proteins of different Babesia spp. In Anaplasma, extensive variation in the pfam01617 gene family accompanies cycling of organism levels in chronic infection. One result from the pioneering research at Onderstepoort is the definition of a related polymorphic gene family that is likely involved in immunity against heartwater disease. We are beginning to understand the sizes of the antigenic repertoires and full definition is close, with the possibility of applying simultaneous high-throughput sequencing to the order of 1 000 small genomes. We also, for the first time, can consider modifying these genomes and looking at effects on persistence and virulence. However, important biological questions remain unanswered; for example, why we are seeing a new emerging Anaplasma infection of humans and is infection of endothelial cells by Anaplasma significant to persistence in vivo.
Show more [+] Less [-]Canine babesiosis
2009
Schoeman, J.P.(University of Pretoria Faculty of Veterinary Science Department of Companion Animal Clinical Studies)
Babesiosis is a tick-borne disease affecting humans and many domestic and wild animals. Domestic animals showing appreciable morbidity and mortality include dogs, cats, cattle and horses. Both canine and feline babesiosis are diseases characterised by haemolytic anaemia, icterus and haemoglobinuria. Canine babesiosis can range from chronic or subclinical to peracute and fatal, depending on the virulence of the species and the susceptibility of the host. This paper deals with canine babesiosis with specific reference to pathogenesis, clinical findings, complications, diagnosis and treatment, as well as newly identified prognostic factors in Babesia rossi babesiosis.
Show more [+] Less [-]A century of tick taxonomy in South Africa
2009
Horak, I.G.(University of Pretoria Onderstepoort Faculty of Veterinary Science Department of Veterinary Tropical Diseases)
Eighty ixodid tick species, 25 argasid tick species and Nuttalliella namaqua occur in South Africa. Twenty-one of the 80 ixodid species and two of the argasid species occur only in this country, while N. namaqua is present only in South Africa and Namibia. Forty-six of the 80 ixodid species and 16 of the 25 argasid species as well as N. namaqua have been described as new species since 1908. People working in South Africa have written or contributed to the descriptions of 24 of these 63 new species, while foreign researchers have described the remainder. New species indigenous to South Africa are still being discovered, while the names of some species, well known because of their veterinary importance, have been altered.
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