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Prospects for controlling trypanosomosis : vector-borne diseases : trypanosomosis Full text
2009
G.A. Vale
The best technical package for the future comprises trypanocidal drugs for temporary relief and the use of insecticide-treated cattle, artificial baits and aerial spraying to attack the vector, to so give more lasting security. Whether this can speed the previously slow progress will depend on overcoming past hindrances to tsetse control : sporadic support, disputes over its desirability, difficulties of sustaining international operations, and poor planning in some instances. The Pan-African Tsetse and Trypanosomiasis Campaign intends to speed the progress but will fail unless it improves its image by breaking its association with the sterile insect technique and quickly executing some cheap and effective operations in large areas. Even then, there could be severe brakes due to Africa's political and financial instability. Overall, the pace of control is likely to increase, but perhaps only a little.
Show more [+] Less [-]Livestock policy and trade issues in SADC : policy and trade issues Full text
2009
B. Hulman
As from 2001, the Southern African Development Community (SADC) has embarked on a course to deepen regional integration through restructuring. Under the new structure SADC has centralised the coordination of its activities to the Secretariat in Gaborone. The former Sector Coordinating Units have been merged into four directorates, one of which is the Food, Agriculture and Natural Resources (FANR) Directorate, which comprises, amongst others, the Livestock Development Unit (LDU).
Show more [+] Less [-]Description and comparison of the pupae of a further two <i>Culicoides</i> (<i>Avaritia</i>) species from the dung of large herbivores in South Africa (Diptera: Ceratopogonidae) Full text
2009
Hilda Nevill | E.M. Nevill | G.J. Venter
In 2007 Nevill, Venter, Meiswinkel & Nevill demonstrated that the pupae of five Culicoides species belonging to the Imicola complex of the subgenus Avaritia could readily be differentiated from one another using various morphological characters. Three of the described species, Culicoides bolitinos Meiswinkel 1989; Culicoides loxodontis Meiswinkel 1992 and Culicoides sp. # 107 (= C. kwagga, Meiswinkel, unpublished thesis 1995), were reared from the dung of large herbivores, which included buffaloes, elephants, white and black rhinoceroses and zebras. However, during that study a further two Avaritia species, neither of which belonged to the Imicola complex, were reared from dung and these are the subject of the present study. For the past 20 years the adults of these two new closely related species have been known as Culicoides sp. # 54 pale form (p.f.) Meiswinkel and Culicoides sp. # 54 dark form (d.f.) Meiswinkel. The taxonomic description and formal naming of the adults of these two species has yet to be done. The present description and comparison of their pupae show that they are two clearly distinct species; that there is no group of morphological characters that can be used to differentiate these two species from the previously described five species of the Imicola complex; and finally that there was no difference between the pupae of C. sp. # 54 d.f. nor C. sp. # 54 p.f. reared from the dung of different host animals.
Show more [+] Less [-]African swine fever : transboundary diseases Full text
2009
M-L. Penrith
African swine fever (ASF) is a devastating haemorrhagic fever of pigs that causes up to 100 % mortality, for which there is no vaccine. It is caused by a unique DNA virus that is maintained in an ancient cycle between warthogs and argasid ticks, making it the only known DNA arbovirus. ASF has a high potential for transboundary spread, and has twice been transported from Africa to other continents - Europe and subsequently the Caribbean and Brazil (1957, 1959) and the Caucasus (2007). It is also a devastating constraint for pig production in Africa. Research at Onderstepoort Veterinary Institute has made and is making important contributions to knowledge of this disease, focusing on the cycle in warthogs and tampans and transmission from that cycle to domestic pigs, resistance to its effects in domestic pigs, and the molecular genetic characterisation and epidemiology of the virus.
Show more [+] Less [-]Field services : eradication and control of animal diseases : animal health management in the 21st century Full text
2009
B.M. Modisane
Prevention, eradication and control of animal diseases, as well as public health assurance are major functions of veterinary authorities. The strategies to control animal diseases differ from disease to disease but are often similar on a disease basis from country to country depending on the main objective of the measure employed. These measures include among others movement control and quarantine, vaccination, treatment and mass slaughtering. However, not every country uses all these control measures at the same time. A combination of measures may be employed to avoid spreading of the disease from infected to clean animals and success is dependent on a variety of factors, including the strength and capacity of the veterinary services, cross border efforts for disease surveillance, political will, diagnostic facilities and financial support.
Show more [+] Less [-]Canine babesiosis : tick-borne diseases Full text
2009
J.P. Schoeman
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 [-]Ecological parameters of <i>Lamproglena hoi</i> (Copepoda: Lernaeidae) infection on the Bushveld smallscale yellowfish, <i>Labeobarbus polylepis</i> (Boulenger, 1907) Full text
2009
A. Austin | A. Avenant-Oldewage
This study describes the distribution and aspects of the ecology of Lamproglena hoi. Bushveld smallscale yellowfish, Labeobarbus polylepis (Boulenger, 1907) were collected during June 2006 from the Phongolo and Assegaai rivers, March 2005 and October 2006 from the Elands River, and January 2007 and June 2008 from the Komati River in Mpumalanga, South Africa and examined for the presence of parasites. Lamproglena hoi specimens were collected from the gill filaments of the host. Specimens were fixed with warm AFA (alcohol-formaldehyde-acetic acid) and preserved in 70 % ethanol. The identification of parasites took place in the laboratories of the University of Johannesburg. Twenty-five copepods (prevalence 21 %, mean intensity = 4.17, abundance = 0.86) were collected on 29 fish in the Phongolo River and 46 copepods (prevalence 40 %, mean intensity = 3.83, abundance = 1.53) were collected on 30 fish in the Assegaai River. One hundred and sixty eight copepods (prevalence 52 %, mean intensity = 12.92, abundance = 6.72) were collected on 25 fish in 2005, and 527 copepods (prevalence 95 %, mean intensity = 27.74, abundance = 26.35) were collected on 20 fish in the Elands River. One hundred and sixteen copepods (prevalence 75 %, mean intensity = 7.73, abundance = 5.80) were collected on 20 fish in 2007, and 273 copepods (prevalence 63 %, mean intensity = 16.06, abundance = 10.11) were collected on 27 fish in 2008 in the Komati River. Labeobarbus polylepis from these four rivers was found to have a relatively high L. hoi infection. Inseminated L. hoi females (immature) attach to the host in winter and their ovaries become conspicuous (mature). In spring fertilized eggs are stored in egg sacs hanging from the body (gravid), indicating that fertilized eggs start to hatch in spring and continued hatching into summer. Parasites prefer the median part of the second gill arch for attachment. No correlation exists between the number of parasites recorded on the gills and the sizes (total lengths) of yellowfish sampled.
Show more [+] Less [-]Detection of natural <i>Trypanosoma vivax</i> infections in pigs with microhaematocrit centrifugation and amplification of ITS1 rDNA Full text
2009
S. Biryomumaisho | S.E. Melville | E. Katunguka-Rwakishaya | G.W. Lubega
Different species of trypanosomes may infect their mammalian hosts both singly or in combination. This study was undertaken to determine the trypanosome species that may be afflicting pigs in Uganda. Blood was collected from pigs of all ages and sexes from two districts, Kasese in Western and Jinja in Central Uganda. Of the 133 pig blood samples from Kasese that were tested for trypanosomes using the microhaematocrit centrifugation technique (MHCT), none was found to be infected. However, of the 253 pigs from Jinja district, nine were infected with trypanosomes of which three had T. vivax as determined by MHCT. However, application of the ITS1 rDNA PCR test revealed that eight pigs had T. vivax in mixed infections and one pig had T. vivax monolithic infection. These observations show that under certain circumstances, pigs may be important reservoirs for, as well as hosts to, T. vivax, contrary to earlier reports.
Show more [+] Less [-]Studies on the cumulative effect of sodium thiomersal on broilers vaccinated with inactivated poultry vaccines Full text
2009
Zeinab M. Sror | Anhar Abd El-Moety | Hanan, M. Ibrahim | M. L. Sayed, A. R. Mahmoud | A. R. Mahmoud | S. M. Shafei | M. H. Khodeir
Merthiolate (Thiomersal) is known to be used as antimicrobial agent in inactivated vaccines without affecting vaccine potency. The present work investigated the effect of thiomersal contents in ND, AI and IBD inactivated vaccines on liver and kidney functions of vaccinated birds. The histopathological effect and the withdrawal time of such mercurial product from vaccinated chicken muscles were also investigated. Results revealed that residual thiomersal contents in ND, AI and IBD were 0.03; 0.02 and 0.03mg/ml respectively. Liver and kidney function parameters showed significant increases in serum activities of alanine aminotransferase (ALT) and serum aspartate aminotransferase (AST) up to the 4th week post vaccination. Serum urea was significantly decreased on the 3rd week in vaccinated birds compared to control ones. Significant increase in serum creatinine in vaccinated chickens was recorded on the 5th week post vaccination. Liver and kidney functions’ parameters remain high allover the experimental period (8 weeks). The histopathological examination of liver specimens revealed degeneration of hepatic cells and congestion of the central vein with inflammatory cell infiltration and congestion of blood vessels as well as coagulative necrosis. The spleen of vaccinated chickens showed depletion of lymphocytes while lungs showed thickening of the alveolar. Mercury contents in muscle were 0.72, 0.52; 0.046 and 0.00 mg/kg on the 1st, 2nd, 3rd and 4th week post last vaccination that considered safe to the consumer. It is recommended that vaccinated poultry with inactivated vaccines containing thiomersal should not be slaughtered before at least 4 weeks and it is preferable to use combined inactivated vaccines to reduce the thiomersal contents as possible.
Show more [+] Less [-]Field study on control of chronic respiratory disease in vertically infected broiler chicks Full text
2009
M. M. Amer | K. M. El-Bayomi | Zenab, M. S. Gera | A. E. A. Hanafei
Our field studies had been carried out after in vitro antibiogram of E. coli to compare the effect of pulmotil (macroloide), enerofloxacin (fluoroquinolones) and doxycycline (tetracycline) in controlling mycoplasma and E. coli as a cause of CRD in broilers. The drugs were used in single or in combination. Two doses at the 3rd and 23rd day of age on performance of commercial broiler Ross derived from mycoplasma SPA-test positive breeders and E. coli positive isolation at the 1st day of age. The prevalence of marked air sac gross lesions in non treated control group indicated the development of CRD and severity of lesions increased with age. The used drugs played a role in controlling infection as treated groups showed milder lesions while more sever lesions were in doxycycline treated group. Protection against mortality was less in the treated pins than untreated ones. Cumulative culls % was low (1.1) in pen treated with enrofloxacin, (1.5) in pulmotil + enrofloxacin, (1.6) in doxycycline, and (1.7) in pulmotil + enrofloxacin; while pulmotil and control were the same (2.2%). Losses expressed as total mortality and culls % were the lowest in pulmotil + enrofloxacin and enrofloxacin (3.2 and 3.6), other treated pins showed the same values (4.2), while the highest was in non treated ones (5.8%). Average Body wt. in pulmotil + enrofloxacin, pulmotil, and enrofloxacin treated pens were higher (1934, 1924 and 1819 gm) than doxycycline (1802 gm), Pulmotil + Doxycycline (1705 gm) and non treated control (1708 gm). CFCR in pulmotil or enrofloxacin and in combination medicated pens were higher than other treatments and non medicated pen. Average day/ week/ gain in control non treated was equal to that of pulmotil or enrofloxacin (65g), slight lower value was in their combination (63g) followed by 58 g in doxycycline. The lowest ADG /w/g value was in pulmotil + doxycycline (52 g). Calculated EEF of treated and non medicated pens were higher than > 280. The medicated pens with either pulmotil or/ enrofloxacin and there compilation were superior (333, 313 and 330; respectively) and close to the farm stander (346). This study pointed out that E. coli, and Mycoplasma with life ND vaccine reduced broiler performance and the used drugs were of values in control such infections. The in vitro antibiotics sensitivity testing of E. coli is important to obtain good results and drug combinations must be carefully performed.
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