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.

Sir Arnold Theiler's research in 1908/09 led to the discovery of the first rickettsial pathogen, Anaplasma marginale, and set the stage for his development and implementation of an effective live vaccine based on a less virulent strain, A. marginale ss. centrale. His 1910 report, describing A. marginale, is among the classic monographs in infectious disease research, presenting not only observations in exacting detail but also highlighting the deductive reasoning leading to association of a new pathogen with a specific disease. With a centennial perspective and both conceptual frameworks and molecular tools unimaginable in Theiler's time, the significance of several observations in the original report- cyclic bacteremia, strain superinfection, and taxonomic position-is now clear and highlight the broad applicability of key principles of pathogen biology.

Veterinary education commenced in South Africa in 1920 at the Onderstepoort Veterinary Institute in South Africa in association with the Transvaal University College, now the University of Pretoria. Sir Arnold Theiler, Director of Veterinary Research and Education, was the first Dean. Today there are 46 veterinary training institutions in Africa of which 21 are in sub-Saharan Africa. Veterinary services are indispensable to the sustained health and wellbeing of animals and humans, and agricultural economies of countries worldwide. Veterinary education, postgraduate training, and research, and adequate numbers of veterinarians, are essential to satisfy the millennium development goals, the objectives of NEPAD and the African Union, and the agreements regulating international trade. The relevance of the veterinary profession internationally is currently subject to profound scrutiny. Its contributions are assessed against major environmental, demographic, political, disease, technological and economic needs. The scope of veterinary training in future will have to emphasise veterinary public health, food safety, emerging diseases, international trade, bioterrorism, and biomedical research, within the context of a one-health system focusing on the interface between wildlife, domesticated animals, humans, and their environment. Within the context of time available, it would mean reducing the time allocated to training in the field of companion animals. A brief history and scope of veterinary education; current international trends in veterinary education and provisioning; and some perspectives on future veterinary training and initiatives applicable to Africa are provided.

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.

The Mkuze Game Reserve (MGR), in north-eastern KwaZulu-Natal Province, South Africa is an African swine fever virus (ASF) controlled area. In a survey conducted in 1978, ASF prevalence in warthogs and Ornithodoros ticks in MGR was determined to be 2 % and 0.06 %, respectively. These values, acknowledged as being unusually low compared to other East and southern African ASF-positive sylvatic-cycle host populations, have not been assessed since. The availability of a sensitive PCR-based virus detection method, developed specifically for the sylvatic tampan host, prompted a re-evaluation of ASF virus (ASFV) prevalence in MGR ticks. Of the 98 warthog burrows inspected for Ornithodoros presence, 59 (60.2 %>) were found to contain tampans and tick sampling was significantly male-biased. Whilst gender sampling-bias is not unusual, the 27 °% increase in infestation rate of warthog burrows since the 1978 survey is noteworthy as it anticipates a concomitant increase in ASFV prevalence, particularly in light of the high proportion (75 %>) of adult ticks sampled. However, despite DNA integrity being confirmed by internal control amplification of the host 16S gene, PCR screening failed to detect ASFV. These results suggest that ASFV has either disappeared from MGR or if present, is localized, occurring at exceptionally low levels. Further extensive surveys are required to establish the ASFV status of sylvatic hosts in this controlled area.

Morphological and histological study were performed in the cecum of ten, six months broiler chicken. The present study was observed that the morphological study distinguished three region from cecum .The proximal ,middle ,and distal represented (23.65%),(42.28%),(34.06%) respectively of the total length of right caecum ,and (23.59%),(43.45%),(23.95%) respectively of the total length of left caecum.The total length of the right caecum were(13.15±0.21)while the total length of left caecum were(13.14±0.44),also was observed that caecal wall composed of four layers( mucosa , submucosa , muscularis and serosa) .The regions of caecum were proximal with developed villi and numerous folds, middle with small villi and numerous folds,while the distal with small villi and avoid of folds .In present study the lymphatic nodules were mostly found in proximal part, but they were less prominent at the distal and least in the middle part of the caecum .the wide and length of lymphatic nodules were more major in the distal part than in the middle and proximal part

The present study showed that the lead had toxic effects on the gill structures of the grass carp (Ctenopharyngodon idella) juveniles such as clubbing molting of epithelial cells, epithelial separation, necrosis, fusion of adjacent lamellar epithelium and hyperplasia of secondary lamellar epithelium, destruction of epithelial cells, curved of epithelial, loose in regular shape of epithelium, bite and bleeding tissues through exposure for 48 hrs. All these histological changes depended on lead concentration and exposure period.

The present study was conducted to compare C-ELISA and Rose-Bengal tests in detection of brucella antibodies in buffalo sera in Mosul city, using 132 adult females of indigenous buffaloes from May 2007 to May 2008. Seroprevalence was 50.8% using C-ELISA, and 28.8% when RBT have been used. The data obtained were analyzed statistically to identify the agreement between C-ELISA and RBT using Kappa value. Kappa index was (0.353), which indicates less agreement between the two tests. There were false-negative results of RBT in 36 samples out of 67 samples positive to C-ELISA, and 7 samples recorded as false-positive with RBT out of 65 samples negative to C-ELISA.

The studied of effects of vitamin C administration on the leukcocyte counts and testing of exercise of male rats. Rats were divided into 4 groups; the first group contain the control and the other group contain the administration with different doses of ascorbic acid (35mg, 75 mg, and 120 mg/day; respectively. The doses were giving by intra-peritoneal injection. Physiological solution was given to the control group (CON) via the same procedure. Exercise performance was based on swim time to fatigue. Blood samples were taken and evaluated at day 10, 20 and 30 days. The lymphocyte percentage was 55.3 ± 5 % for CON on day 28. For all C groups, the range of the lymphocyte percentage was 54.5 %- 64.1 % (p < 0.001). Swim time was 1.6 ± 0.3 min at day 30. This value was increased to 5.1- 8.4 min for the C groups (p < 0.001).

This study was done to find out the effect of seasonal variations on the hematological and blood biochemical parameters of local cattle raised in Maysan Governorate. A number of 40 healthy cows were selected for the study during winter and summer seasons, blood samples were collected in each of the two seasons and were analyzed for some hematological and biochemical parameters. The results in the winter season showed significantly higher values of Mean Corpuscular Volume, glucose, total protein, albumin, globulin, bilirubin and creatinine but lower values of total white blood cells count, differential leukocyte count, hemoglobin concentration, Mean Corpuscular Hemoglobin, Mean Corpuscular Hemoglobin Concentration, AST and ALT than that of the same animals during the summer season. However, no significant differences in the erythrocyte count, haematocrite between the two seasons were observed in the local cattle.