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Cercariae developing in <i>Lymnaea natalensis</i> Krauss, 1848 collected in the vicinity of Pretoria, Gauteng Province, South Africa
2008
E.B.E. Moema | P.H. King | C. Baker
Freshwater snails are known to serve as first intermediate hosts for various parasitic diseases such as schistosomosis and fasciolosis. Snails were collected on several occasions in the proximity of Pretoria, South Africa and their cercarial sheddings were studied. This article describes three different types of cercariae shed by the freshwater snail, Lymnaea natalensis, viz. a fork-tailed cercaria of a Trichobilharzia sp., an avian parasite belonging to the family Schistosomatidae, an echinostomatid cercaria of the family Echinostomatidae, also avian parasites and a xiphidiocercaria of the family Plagiorchiidae which parasitise avians and amphibians. The morphology of these cercariae was studied by light and scanning electron microscopy.
Show more [+] Less [-]Epidemiological survey on gastro-intestinal and blood-borne helminths of dogs in north-east Gabon : research communication
2008
B. Davoust | T. Normand | O. Bourry | H. Dang | E. Leroy | G. Bourdoiseau
A survey of helminth parasites was carried out on 198 dogs living in almost complete liberty in villages in the northeast of Gabon. Faeces and blood samples were collected and analysed. Dirofilariaimmitis antigen was detected in 13.6 % of dogs using the SNAP 3Dx® test, a commercially available enzyme-linked immunosorbent assay (ELISA). Faecal examination revealed that 91.4 % of dogs were infected by intestinal helminths. Ascarids were found in 58.5 % of the samples. Trichuris vulpis was observed in 49.5 % of cases, and Uncinaria spp. and Ancylostoma spp. in 34.8 %, Spirocerca lupi in 25.3 % and Capillaria spp. in 10.6 %. Cestode embryophores were found in 8.6 % of the samples.
Show more [+] Less [-]Acute and long-term effects of exposure to sodium monofluoroacetate (1080) in sheep
2008
Gooneratne, S.R.(Cell Biology Group Agriculture and Life Sciences Division ,Centre for Environmental Toxicology Landcare Research) | Eason, C.T.(Centre for Environmental Toxicology Landcare Research ,Lincoln University Bio-Protection and Ecology Division) | Milne, L.(Centre for Environmental Toxicology Landcare Research) | Arthur, D.G.(Lincoln University LabWorks Animal Health Ltd) | Cook, C.(Ruakura Research Centre) | Wickstrom, M.(Centre for Environmental Toxicology Landcare Research ,University of Saskatchewan Western College of Veterinary Medicine)
Acute and long-term effects of a single, relatively high oral dose (0.25 and 0.30 mg/kg) of sodium monofluoroacetate (1080) on the survival and productivity of sheep were evaluated to establish a better understanding of 1080 poisoning and identify more specific changes diagnostic of toxicosis. In survivors, clinical signs of acute 1080 toxicosis such as salivation and lethargy were generally very mild. Fasted animals were more prone to 1080 toxicity. In animals that died, more severe signs, including tachypnoea, dyspnoea, and tremors occurred for 15-20 min prior to death. 1080 concentrations were highest in the blood > heart > skeletal muscle > liver. 1080 could not be detected in any of these organs of the animals that survived. Serum citrate concentrations were elevated for 4 days after dosing. No clinical or biochemical abnormalities were found in any animal after 4 days. Histopathological lesions were most marked in the heart and lung with inflammation, necrosis, and scattered foci of fibrous tissue in the myocardium, pulmonary oedema and inflammation of the lung. No adverse long-term effects on general health or reproductive performance were observed in any sheep that survived the first 4 days following exposure to 1080. The most reliable diagnostic indicators of 1080 exposure in sheep were measurement of its residues in blood, skeletal muscle and ruminal contents, increased serum citrate concentration, elevated heart rate, and characteristic electrocardiograph changes (up to 4 days after exposure). Death from 1080 is most likely to occur within 96 h, and animals that survived this period appeared normal.
Show more [+] Less [-]Prevalence of Theileria equi and Babesia caballi infections in horses belonging to resource-poor farmers in the north-eastern Free State Province, South Africa
2008
Motloang, M.Y.(University of the Free State ,ARC-Onderstepoort Veterinary Institute) | Thekisoe, O.M.M.(Obihiro University of Agriculture and Veterinary Medicine National Research Center for Protozoan Diseases) | Alhassan, A.(Obihiro University of Agriculture and Veterinary Medicine National Research Center for Protozoan Diseases) | Bakheit, M.(University of the Free State) | Motheo, M.P.(University of the Free State) | Masangane, F.E.S.(University of the Free State) | Thibedi, M.I.(University of the Free State) | Inoue, N.(Obihiro University of Agriculture and Veterinary Medicine National Research Center for Protozoan Diseases) | Igarashi, I.(Obihiro University of Agriculture and Veterinary Medicine National Research Center for Protozoan Diseases) | Sugimoto, C.(Hokkaido University Center for Zoonosis Control) | Mbati, P.A.(University of the Free State)
The prevalence of Theileria equi and Babesia caballi infections in the north-eastern Free State Province of South Africa was determined by examination of thin and thick Giemsa-stained blood smears, IFAT and PCR. No parasites were detected by microscopy from any blood samples collected at five study sites, Qwaqwa, Kestell, Harrismith, Vrede and Warden. Of the tested serum samples, 28/29 (96.5 %), 20/21 (95.2 %) and 42/42 (100 %) were positive by IFAT for T. equi infections in Harrismith, Kestell and Qwaqwa, respectively, and 5/29 (17.2 %>), 13/21 (61.9 %>) and 30/42 (71.4 %>) were sero-positive for B. caballi infections in Harrismith, Kestell and Qwaqwa, respectively. All DNA samples from the study sites were negative for B. caballi infections by PCR, but five samples, two from each of Kestell and Warden and one from Vrede, were PCR positive for T. equi infections. The high prevalence of antibodies against T. equi and B. caballi in the sampled horses indicates that the animals had been exposed to T. equi and B. caballi infections but the absence of parasitaemia and very low number of positive PCR samples, however, imply that T. equi and B. caballi are endemically stable in the north-eastern Free State Province.
Show more [+] Less [-]Characterization of pigeon paramyxoviruses (Newcastle disease virus) isolated in South Africa from 2001 to 2006
2008
Abolnik, C.(ARC-Onderstepoort Veterinary Institute) | Gerdes, G.H.(ARC-Onderstepoort Veterinary Institute) | Kitching, J.(Stellenbosch Provincial Veterinary Laboratory) | Swanepoel, S.(Deltammune Laboratorie) | Romito, M.(ARC-Onderstepoort Veterinary Institute) | Bisschop, S.P.R.(University of Pretoria Poultry Reference Laboratory)
Pigeon paramyxovirus type 1 (PPMV-1), a variant of Newcastle disease virus that primarily affects doves and pigeons has been isolated in South Africa since the mid-1980s. Phylogenetic evidence indicates that pigeon paramyxovirus type 1 viruses were introduced into South Africa on multiple occasions, based on the presence of two separate lineages, 4bi and 4bii, that have been circulating in Europe and the Far East since the early 1990s. During 2006, a PPMV-1 virus was isolated from an African ground hornbill (Bucorvus leadbeateri) which became acutely infected with PPMV-1 and died, probably after scavenging off infected dove carcasses in the region, since a closely-related PPMV-1 strain was also isolated from doves collected nearby. The hornbill isolate had ICPI and MDT values characteristic of PPMV-1 strains. The threat of PPMV-1 to poultry production and biodiversity in southern Africa highlights the importance of monitoring the spread of this strain.
Show more [+] Less [-]Can osteophagia provide giraffes with phosphorus and calcium?
2008
Bredin, I.P.(Faculty of Veterinary Science Veterinary Wildlife Unit) | Skinner, J.D.(Faculty of Veterinary Science Veterinary Wildlife Unit) | Mitchell, G.(Faculty of Veterinary Science Veterinary Wildlife Unit ,University of Wyoming Department of Zoology and Physiology)
The daily requirement for calcium and phosphorus by giraffes to sustain the growth and maintenance of their skeletons is large. The source of sufficient calcium is browse. The source of necessary phosphorus is obscure, but it could be osteophagia, a frequently observed behaviour in giraffes. We have assessed whether bone ingested as a result of osteophagia can be digested in the rumen. Bone samples from cancellous (cervical vertebrae) and dense bones (metacarpal shaft) were immersed in the rumens of five sheep, for a period of up to 30 days, and the effect compared to immersion in distilled water and in artificial saliva for 30 days. Distilled water had no effect on the bones. Dense bone samples were softened by exposure to the saliva and rumen fluid, but did not lose either calcium or phosphorus. In saliva and rumen fluid the cancellous bone samples also softened, and their mass and volume decreased as a result of exposure to saliva, but in neither fluid did they lose significant amounts of calcium and phosphorus. We conclude that although saliva and rumen fluid can soften ingested bones, there is an insignificant digestion of bones in the rumen.
Show more [+] Less [-]The financial cost implications of the highly pathogenic notifiable avian influenza H5N1 in Nigeria
2008
Fasina, F.O.(National Veterinary Research Institute Viral Research Department ,University of Pretoria Faculty of Veterinary Science Department of Production Animal Studies) | Sirdar, M.M.(Military Cooperative Corporation) | Bisschop, S.P.R.(University of Pretoria Faculty of Veterinary Science Department of Production Animal Studies)
Nigeria and several other nations have recently been affected by outbreaks of the Asian H5N1 strain of highly pathogenic notifiable avian influenza (HPNAI) virus, which affects the pou sts associated with the current avian influenza outbreaks. The evaluation used epidemiological data, production figures and other input parameters to determine the final costs. An infection involving 10 % of the commercial bird population will cost Nigeria about $245 million and a worse scenario may lead to a loss of around $700 million. The results urge governments to invest more in measures aimed at the effective prevention of HPNAI and to consider the huge economic losses associated with the disease. Finally, an inter-disciplinary approach to managing and controlling HPNAI outbreaks is encouraged.
Show more [+] Less [-]Field experiences with early pregnancy diagnosis by progesterone-based ELISA in sows
2008
Boma, M.H. | Bilkei, G.
In four Kenyan pig breeding units the pregnancy diagnosis of sows has been carried out in two groups: Group 1 (n = 1911): the sows were transrectaly pregnancy tested between Days 17-22 post-mating by ultrasound. Sows testing non-pregnant immediately received one dose of 400 IU pregnant mare serum gonadotropin (PMSG) (equine chorion gonadotropin, eCG) and 200 IU human chorion gonadotropin (hCG). On showing signs of oestrous, the animals were subsequently artificially inseminated (AI). Group 2 (n = 1923): sows were pregnancy tested by serum progesterone (P4)-based enzyme-linked immunosorbent assay (ELISA) on Day 17 post-breeding. P4 concentrations were categorized as positive (> 5 ng/ml) or negative (< 5 ng/ml). Sows testing nonpregnant immediately received one dose of 400 IU PMSG and 200 IU hCG by injection, and were subsequently artificially inseminated. The following parameters were evaluated: sows diagnosed non-pregnant, days from first post-weaning insemination until the sows were inseminated at their first return to oestrus; farrowing rate and total piglets born and number of live-born piglets in litters. The percentage of sows diagnosed non-pregnant in the two groups, as well as the totals of born piglets and of live-born piglets in litters did not differ significantly between the two groups. The number of days from the first post-weaning mating until the sows were artificially inseminated at their first return to oestrus and the administration of eCG and hCG was shorter (P < 0.01) and farrowing rate was higher (P < 0.01) in the ELISA-tested sows.
Show more [+] Less [-]An immunohistochemical study of ovarian innervation in the emu (Dromaius novaehollandiae)
2008
Madekurozwa, M-C.(University of Pretoria Faculty of Veterinary Science Department of Anatomy and Physiology)
The present study investigated the distribution of nerves in the ovary of the emu. The neuronal markers, protein gene product 9.5, neurofilament protein and neuron specific enolase demonstrated the constituents of the extrinsic and intrinsic ovarian neural systems. The extrinsic neural system was composed of ganglia in the ovarian stalk, as well as nerve bundles, which were distributed throughout the ovary. Isolated neuronal cell bodies, in the medulla and cortex, formed the intrinsic neural system. An interesting finding of the study was the presence of nerve bundles, circumscribed by lymphocytes, in the ovarian stalk. The findings of the study indicate that the distribution of nerve fibres and neuronal cell bodies in the emu ovary is similar, but not identical to that of the domestic fowl and ostrich.
Show more [+] Less [-]Prevalence of bovine trypanosomosis in Central Mozambique from 2002 to 2005
2008
Specht, E.J.K.(Laboratório Regional de Veterinária)
The study is the result of analyzing 16 895 blood smears of cattle collected at 180 sites in the provinces of Manica, Sofala, Zambézia and Tete in Mozambique. Of the blood smears 73.9 % were from Manica, 11.8 % from Tete, 8.5 % from Sofala and 5.8 % from Zambézia; 75.6 % of these were collected from smallholder cattle. Infections with trypanosomes were highest in smallholder cattle from Sofala Province with 36.8 % of the 872 blood smears examined positive for trypanosomes, and lowest in cattle of commercial farmers in Manica Province with only 6.2 % of 2 252 blood smears being positive. Trypanosoma congolense was the predominant species, followed by Trypanosoma vivax and Trypanosoma brucei sensu lato. Trypanosoma brucei, which also infects humans, was more frequent in the districts of Buzi, Mutarara and Morrumbala with 15.1 %, 10.5 % and 9.8 % of all examined cattle in 2005 being infected with it, respectively. The results show a significant increase in the infection rate with trypanosomes compared with results obtained in previous years by the Regional Veterinary Laboratory in Manica Province and by the Regional Tsetse and Trypanosomiasis Control Programme in Zambézia, Tete and Sofala provinces.
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