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Relative economic benefits of tactical anthelmintic treatment and urea-molasses block supplementation of Boer goats raised under extensive grazing conditions at Onderstepoort, Pretoria, South Africa
2008
A.F. Vatta | R.C. Krecek | R.A. Pearson | M.F. Smith | M.O. Stenson | E.F. Van Wijk | L.J.S. Harrison
The potential economic benefits of combining tactical anthelmintic treatment for gastrointestinal nematodes and nutritional supplementation with urea-molasses blocks were examined in Boer goats raised under extensive grazing conditions in the summer rainfall area of South Africa. Eight groups of nine goats were monitored over a 12-month period from 1 October 2002 to 9 October 2003. Ad libitum nutritional supplementation with urea-molasses blocks was provided when the goats were housed at night, during the summer (wet season -December 2002 to February 2003), and / or the winter (dry season -June 2003 to August 2003). All the goats were treated symptomatically for Haemonchus contortus infection when deemed necessary by clinical examination of the conjunctiva for anaemia using the FAMACHA© system. Half the groups were tactically treated for gastrointestinal nematodes in mid-summer (28 January 2003). Under the symptomatic treatment, climatic and extensive grazing conditions encountered during the trial, feed supplementation in the winter dry season had the greatest economic benefit and is therefore recommended. Tactical anthelmintic treatment afforded no additional advantage, but the nematode challenge was lo
Mostrar más [+] Menos [-]Prevalence of serotype specific antibody to equine encephalosis virus in Thoroughbred yearlings South Africa (1999-2004)
2008
P. G. Howell | Jane P. Nurton | Daleen Nel | Carina W. Lourens | A. J. Guthrie
Cohorts of yearlings were sampled over a period of 6 years in a retrospective serological survey to establish the annual prevalence of serotype specific antibody to equine encephalosis virus on Thoroughbred stud farms distributed within defined geographical regions of South Africa. Seasonal seroprevalence varied between 3.6% and 34.7%, revealing both single and multiple serotype infections in an individual yearling. During the course of this study serotypes 1 and 6 were most frequently and extensively identified while the remaining serotypes 2, 3, 4, 5 and 7 were all identified as sporadic and localized in fections affecting only individual horses. This study of the seasonal prevalence of equine encephalosis virus has a corollary and serves as a useful model in the seasonal incidence of the serotypes of African horse sickness and bluetongue in regions where the respective diseases are endemic.
Mostrar más [+] Menos [-]Value of tests for evaluating udder health in dairy goats: somatic cell counts, California Milk Cell Test and electrical conductivity
2008
I.M. Petzer | E.F. Donkin | E. Du Preez | J. Karzis | T.J. Van der schans | J.C. Watermeyer | R. Van Reenen
The value of electric conductivity (EC), California Milk Cell Test (CMCT) and somatic cell count (SCC) as diagnostic tools was investigated in dairy goats. Conductivity colour reading correlated with SCC. Milk samples with conductivity colour red had significantly higher SCC than those with conductivity colours green and orange (P < 0.001). There were moderate positive correlations between CMCT (R2 = 0.470), and conductivity score and CMCT and conductivity colour readings (R2 = 0.597). Conductivity scores were significantly (P < 0.001) higher during and after intra-mammary treatment with Cloxamast LC and conductivity colours were significantly different between treatment and control groups (P < 0.001). There was a weak positive correlation between conductivity colour and stage of lactation (R2 = 0.317) and a moderately positive correlation between conductivity score and stage of lactation (R2 = 0.523). A moderately negative correlation was shown between milk yield and conductivity score (R2 = -0.426) and between milk yield and conductivity colour (R2 = -0.433). Moderate positive correlations were present between CMCT and SCC (R2 = 0.689) and between CMCT and stage of lactation (R2 = 0.459). CMCT ratings were significantly different (P < 0.001) for the intramammary treatment groups. CMCT ratings for infected and non-infected udder halves (P = 0.008) were significantly different; as were those for infected and non-infected udder halves and for left and right udder halves separately (P = 0.010). CMCT ratings for milk samples with SCC above and below 750 x 103 cells per mℓ were significantly different (P < 0.001) as well as for milk from treated and control udder halves with SCC below or above 750 x 103 cells per mℓ (P < 0.001). CMCT was found to be more accurate for indicating the absence of mastitis than for diagnosing it. There were significant differences in log SCC between treatment and control groups, during and after treatment. Infected udder halves had significantly higher log SCC than non-infected udder halves before and after treatment, but not during treatment. There was a moderate positive correlation between stage of lactation and SCC (R2 = 0.438).
Mostrar más [+] Menos [-]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.
Mostrar más [+] Menos [-]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.
Mostrar más [+] Menos [-]Ixodid ticks on dogs belonging to people in rural communities and villages in Maputo Province, Mozambique
2008
De Matos, C.(Instituto de Investigação Agrária de Mozambique ,University of Pretoria Faculty of Veterinary Science Department of Veterinary Tropical Diseases) | Sitoe, C.(Instituto de Investigação Agrária de Mozambique) | Neves, L.(Universidade Eduardo Mondlane Faculdade de Veterinária) | Bryson, N.R.(University of Pretoria Faculty of Veterinary Science Department of Veterinary Tropical Diseases) | Horak, I.G.(University of Pretoria Faculty of Veterinary Science Department of Veterinary Tropical Diseases,Onderstepoort Veterinary Institute ,University of the Free State Department of Zoology and Entomology)
The species composition and geographic distribution of ixodid ticks infesting domestic dogs owned by people in rural communities and villages in Maputo Province was established by collecting ticks from dogs at each of 27 localities spread throughout the province. Ticks were collected from a total of 132 dogs, and nine species belonging to four genera were identified. One dog was infested with six species, three with five and 13 with four species. Haemaphysalis elliptica followed by Rhipicephalus simus were present on dogs at most localities, and their geographic distribution in Maputo Province has been mapped for the first time.
Mostrar más [+] Menos [-]In vitro isolation of Ehrlichia ruminantium from ovine blood into Ixodes scapularis (IDE8) cell cultures
2008
Zweygarth, E.(Onderstepoort Veterinary Institute) | Josemans, A.I.(Onderstepoort Veterinary Institute) | Steyn, H.C.(Onderstepoort Veterinary Institute)
Four stocks of Ehrlichia ruminantium (Welgevonden, Ball3, Nonile and Blaauwkrans), the causative agent of heartwater in domestic ruminants, were isolated into Ixodes scapularis (IDE8) tick cells using the leukocyte fraction of the blood of infected sheep. Organisms of two of the E. ruminantium stocks (Welgevonden and Blaauwkrans) propagated in IDE8 cells were also successfully used to infect bovine endothelial cells. All stocks were successfully propagated in IDE8 cells using Dulbecco's modified Eagle's medium nutrient mixture Ham F-12 containing 10 % foetal bovine serum (FBS). The technique should be included in any attempt to isolate uncharacterized E. ruminantium stocks.
Mostrar más [+] Menos [-]Prevalence of serotype specific antibody to equine encephalosis virus in Thoroughbred yearlings in South Africa (1999-2004)
2008
Howell, P.G.(University of Pretoria Faculty of Veterinary Science Equine Research Centre) | Nurton, Jane P.(University of Pretoria Faculty of Veterinary Science Equine Research Centre) | Nel, Daleen(University of Pretoria Faculty of Veterinary Science Equine Research Centre) | Lourens, Carina W.(University of Pretoria Faculty of Veterinary Science Equine Research Centre) | Guthrie, A.J.(University of Pretoria Faculty of Veterinary Science Equine Research Centre)
Cohorts of yearlings were sampled over a period of 6 years in a retrospective serological survey to establish the annual prevalence of serotype specific antibody to equine encephalosis virus on Thoroughbred stud farms distributed within defined geographical regions of South Africa. Seasonal seroprevalence varied between 3.6 % and 34.7 %, revealing both single and multiple serotype infections in an individual yearling. During the course of this study serotypes 1 and 6 were most frequently and extensively identified while the remaining serotypes 2, 3, 4, 5 and 7 were all identified as sporadic and localized infections affecting only individual horses. This study of the seasonal prevalence of equine encephalosis virus has a corollary and serves as a useful model in the seasonal incidence of the serotypes of African horse sickness and bluetongue in regions where the respective diseases are endemic.
Mostrar más [+] Menos [-]Helminth parasites of Natal long-fingered bats, Miniopterus natalensis (Chiroptera: Miniopteridae), in South Africa
2008
Junker, K.(University of Pretoria Department of Veterinary Tropical Diseases) | Bain, O.(Muséum National d'Histoire Naturelle, Parasitologie comparée et Modèles expérimentaux) | Boomker, J.(University of Pretoria Department of Veterinary Tropical Diseases)
The helminth community infecting Miniopterus natalensis was studied at two localities, the De Hoop Nature Reserve (DHNR) (n = 57), Western Cape Province and Pretoria (n = 12), Gauteng Province, South Africa. Hosts from the DHNR had formed part of an earlier, unrelated study and were all pregnant females. A single hymenolepidid cestode species, the nematodes Molinostrongylus ornatus and Litomosa chiropterorum together with nematodes of the subfamily Capillariinae were present at both study sites, while a single digenean, Allassogonoporus sp., was only found in hosts from the DHNR. The prevalence of helminth infections was high at both localities, 68.4 % in the DHNR and 77.7 % in Pretoria, whereas the mean intensity of infection was low at the DHNR (3.76 ± 3.15), but higher in Pretoria (10.4 ± 9.9). Molinostrongylus ornatus and, to a lesser extent L. chiropterorum, were the main contributors to the higher intensities in Pretoria. The species richness ranged from 0 to 4 at both localities.
Mostrar más [+] Menos [-]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.
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