The pathogenic effect of representative local isolates of Aeromonas organisms was studied on 1٠0 native breed chickens. At 2 weeks of age, one hundred chicks were grouped into four equal groups (1-4); 25 birds each; after collection of fecal from all groups, examined and proved to be free from Aeromonas species. All groups were subcutaneously (s.c) inoculated with 0.5 ml containing 9×105 cfu /bird. Group 1 of chickens was infected by A. hydrophila; while group 2 was infected with A. caviae. The third group was infected with A. sobria; while, chicks of Group 4 were kept as non infected control. Results were showed mild clinical signs in some birds in the form of alternative diarrhea. Post mortem lesions showed general congestion of all carcasses. In severely emaciated cases the lesions were confined to the intestine, which filled with watery fluid and distended with gas. Results of Aeromonas reisolation revealed that all collected weekly fecal swabs were positive. While, percentage of A. hydrophila and A. caviae was 100% out of all tested organs, while isolation of A. sobria was 100%, 100% and 80% from liver, intestine and heart; respectively. Histopathological examination of infected chicken organs showing focal coaggulative necrosis in liver with mononuclear cells infiltration that varied in severity between groups as less severe in A. hydrophila (Gr.1) than A. caviae (Gr. 2), while A. sobria (Gr. 3) was markedly affected showing severe degenerated and dissociated hepatocytes. Intestinal changes were severe in group 3 than 2 while group 1 showing the mildest comparatively the changes was consist of necrosed mucosa, gland with leucocytic infiltration in lamina propria. Under the condition of our study we can conclude that the used Aeromonas isolates from field diseased chickens were of mild pathogenicity to s.c. inoculated 12 days old Fayoumi chicks with long course affection.

In an attempt to isolate reticuloendotheliosis virus (REV) from field cases, plasma of commercial broiler chickens-suspect to have virus infection-were examined. Samples were inoculated in chicken embryo fibroblasts and after proper incubation infected cultures were assayed for REV-antigen by ELISA, immuno-peroxidase (IP) plaque assay, and PCR.Specificity of ELISA and IP was evaluated by comparing their results with that obtained by PCR. REV could be isolated and virus antigen was detected in cell cultures by all three techniques. Results showed that PCR and ELISA are more specific than IP in detection of REV-antigen. However, the sensitivity of ELISA was affected by the criterion used for determination of the cut-off point. Further studies are needed for full characterization of the isolated virus by using reference antiserum or strain specific primers for PCR.

Several studies on ticks infesting small mammals, including elephant shrews, have been conducted in South Africa; however, these studies have included only a single four-toed elephant shrew and no hedgehogs. This study thus aimed to identify and quantify the ixodid ticks infesting four-toed elephant shrews and Southern African hedgehogs. Four-toed elephant shrews (Petrodromus tetradactylus) were trapped in dense shrub undergrowth in a nature reserve in north-eastern KwaZulu-Natal. They were separately housed, first in cages and later in glass terraria fitted with wire-mesh bases to allow detached ticks to fall through for collection. Southern African hedgehogs (Atelerix frontalis) were hand caught on a farm in the eastern region of the Northern Cape Province and all visible ticks were collected by means of tweezers while the animals were anaesthetised. The ticks from each animal were preserved separately in 70% ethanol for later identification and counting. The immature stages of five ixodid tick species were collected from the elephant shrews, of which Rhipicephalus muehlensi was the most common. It has not been recorded previously on any species of elephant shrew. Three ixodid tick species were collected from the hedgehogs. Large numbers of adult Haemaphysalis colesbergensis, which has not been encountered previously on hedgehogs, were collected from these animals. Four-toed elephant shrews are good hosts of the larvae and nymphs of R. muehlensi, and Southern African hedgehogs are good hosts of adult H. colesbergensis.

The present work was performed to study the effect of chromium piclonate and ⁄ or ascorbic acid supplementation on the performance of growing kids during hot summer season (33.6oC and 74.2% RH). A total number of twenty four weaned commercial kids were randomly distributed into four treatment groups of 6 kids per each Kids in all treatments were equal in number and had nearly similar initial body weight. The first group was fed the basal diet and served as control (0.0 supplementation), while the other three groups were fed diets supplemented with 75 mg/kg diet chromium piclonate, 800 mg/ kg diet ascorbic acid and 75 mg / kg diet chromium piclonate + 800 mg ascorbic acid, respectively. The results obtained for growing Kids showed that the final live body weight and daily body gain were increased significantly (P < 0.05 or 0.01) during 210 and 270 days for Kids fed diets supplemented with chromium piclonate, ascorbic acid and chromium piclonate + ascorbic acid. However, the supplementation of chromium piclonate + ascorbic acid seemed to be the best significant performance. The results obtained for growing Kids showed that the daily feed intake, feed conversion, water ⁄ feed intake ratio, water ⁄ daily gain ratio were increased significantly (P < 0.05 or 0.01) during the experimental periods for Kids fed diets supplemented with chromium piclonate, ascorbic acid and chromium piclonate + ascorbic acid. The Results showed that water intake, rectum temperature and respiration rate were not significantly affected by previous treatments. The best margin was obtained in group fed on the diet supplemented with chromium piclonate + ascorbic acid. All carcass traits were increased insignificantly due to dietary chromium piclonate and ⁄or ascorbic acid supplementation. Serum total proteins were increased significantly (P < 0.05), in group three only while the cholesterol level and triglycerides decreased significantly (P<0.05) in Kids treated with chromium piclonate as compared with the control group under summer heat stress conditions. Serum albumin, globulin, urea-, creatinine, AST, WBCs, RBCs MCV, MCH and Hb content were insignificantly affected by chromium piclonate and ⁄or ascorbic acid supplementation to the kids’ diets. Finally, it could be concluded that supplementation of 75 mg chromium piclonate + 800 mg ascorbic acid / kg diet to the kid diets is necessary to improve the productivity, under the summer conditions

Ticks infesting cattle represent a serious problem for improvement of cattle productivity in South Sudan. There has been limited information on ticks and tick-borne diseases in southern Sudan. This study was initiated to update the current distribution of ticks infesting cattle in the Central Equatoria region of South Sudan. The surveys for the present study were conducted at various cattle camps in Juba, Mangalla and Terekeka between December 2004 and June 2005. A total of 2322 ticks were collected from the bodies of 88 randomly selected cattle. Ticks were preserved in 70% ethanol for later identification. Seven ixodid tick species were found to infest cattle in Juba whilst six species were recorded in Mangalla and only four species in Terekeka. Amblyomma variegatum was the most common and widely distributed species found on cattle across all the study locations. Amblyomma lepidum was not found during this study. Based on these findings, it would be advisable to preempt the situation and institute containment procedures before possible East Coast fever outbreaks occur.

Bovine tuberculosis (BTB), a chronic disease of mammals caused by Mycobacterium bovis, is a threat to South African wildlife. It has been reported that African buffaloes (Syncerus caffer) are reservoir hosts of BTB in South African wildlife populations. This study reports on the molecular identification and typing of 31 M. bovis isolates collected between 1993 and 2008, mainly from buffaloes but also from two lions and a bush pig, in the Hluhluwe-iMfolozi Park (HiP) in KwaZulu-Natal. To study the dynamics of BTB in the buffalo populations, 28 M. bovis isolates from the HiP and epidemiologically related parks were characterised using regions of difference deletion analysis for species identification and spoligotyping, variable number of tandem repeats (VNTR), polymorphic G–C-rich sequences and IS6110 restriction fragment length polymorphism (RFLP) genotyping methods. At least three distinct M. bovis genotypes were found amongst HiP samples. The combination of VNTR typing (using a 16-loci panel) and IS6110 RFLP revealed the presence of three additional genetic profiles in individual buffaloes, demonstrating that the highest level of discrimination was achieved by these typing methods. One of the observed spoligotypes (SB0130) was dominant and represented 75% of isolates from buffaloes. A novel M. bovis spoligotype (SB1474), which is reported for the first time in this study, was observed in 14.3% of isolates from buffaloes. Based on the observed genetic relationships, the findings suggest independent introductions from at least three unrelated sources. These findings improve the knowledge regarding the diversity of circulating M. bovis strains in the HiP.

Bovine viral diarrhoea virus (BVDV) infection is an important viral infection affecting the cattle industry today. The prevalence of this infection in South African feedlots is unknown. Ear notch biopsies were collected from chronic poor doers and animals that appeared unthrifty upon entering feedlots, as well as animals entering the hospital pen with respiratory disease for the first time. A total of 1690 samples were collected: 1074 from the former category and 616 from the latter. A routine immunohistochemistry staining protocol showed that 49 animals tested positive, of which 43 (4%) came from the feedlot entry group and six (1%) from the hospitalised group. The prevalence of persistently infected cattle from this selected, nonrandom sample entering six large South African feedlots was found to be 2.9%, which is higher than the international rule of thumb that 0.5% of all cattle entering feedlots are persistently infected. There was no clear correlation between persistent infection and respiratory disease. Serum samples were also collected when possible and 10 positive cases were found. Results from enzyme-linked immunosorbent assays for antigen and antibody performed on these sera correlated well with those from the immunohistochemistry staining method in six cases, but in four cases the animals tested falsely positive owing to nonspecific staining. Immunohistochemistry staining on ear notch biopsies is thus a reliable diagnostic method to identify persistently infected animals with BVDV, but the pathologist should be aware of nonspecific positive staining.

Despite many studies regarding tick ecology, limited information on long-term changes in tick populations exist. This study assessed the long-term population dynamics of the less frequently collected questing ixodid ticks in the Kruger National Park (KNP). From 1988 to 2002, monthly dragging of the vegetation was performed in three habitats (grassland, woodland and gully) at two sites in the KNP (Nhlowa Road, Landscape Zone 17, and Skukuza, Landscape Zone 4). Amblyomma marmoreum and Rhipicephalus evertsi evertsi were collected as larvae most commonly. Most A. marmoreum larvae were collected at Skukuza and numbers peaked from March to July. More R. evertsi evertsi larvae were collected at Nhlowa Road and numbers peaked in summer and in winter, while at Skukuza there was a single peak in spring. Haemaphysalis elliptica, Rhipicephalus simus and Rhipicephalus turanicus were collected as adults most commonly. More Ha. elliptica and R. turanicus were collected at Nhlowa Road than at Skukuza, while R. simus numbers from the two sites were approximately equal. Ha. elliptica were collected most often between February and June, and R. simus and R. turanicus during February and March. All three species were collected more frequently in gullies than in grassland or woodland. Their numbers increased in 1994/1995 following an eruption of rodents, the preferred hosts of the immature stages. The different host-seeking strategies of ticks largely determine the development stage at which they are likely to be collected during vegetation dragging and reflect a complex interaction between ticks, their hosts and the environment.

The study aimed to assess the long-term population dynamics of questing Rhipicephalus appendiculatus and Rhipicephalus zambeziensis in two landscape zones of the Kruger National Park (KNP). Ticks were collected by dragging the vegetation monthly in three habitats (grassland, woodland and gully) at two sites in the KNP (Nhlowa Road and Skukuza) from August 1988 to March 2002. Larvae were the most commonly collected stage of both species. More R. appendiculatus were collected at Nhlowa Road than at Skukuza, with larvae being most abundant from May to August, while nymphs were most abundant from August to December. Larvae were most commonly collected in the gullies from 1991 to 1994, but in the grassland and woodland habitats from 1998 onwards. Nymphs were most commonly collected in the grassland and woodland. More R. zambeziensis were collected at Skukuza than at Nhlowa Road, with larvae being most abundant from May to September, while nymphs were most abundant from August to November. Larvae and nymphs were most commonly collected in the woodland and gullies and least commonly in the grassland (p < 0.01). The lowest numbers of R. appendiculatus were collected in the mid-1990s after the 1991/1992 drought. Rhipicephalus zambeziensis numbers declined after 1991 and even further after 1998, dropping to their lowest levels during 2002. The changes in numbers of these two species reflected changes in rainfall and the populations of several of their large herbivore hosts, as well as differences in the relative humidity between the two sites over time.

Objective—To assess whether the Pfirrmann system for grading lumbar intervertebral disk (IVD) degeneration in humans can also be used in dogs. Animals—202 dogs. Procedures—Magnetic resonance imaging was used to obtain images of vertebral segments from dogs, which were reviewed separately by 3 observers who graded the extent of degeneration in each visible IVD by use of the Pfirrmann classification system used for grading lumbar IVD degeneration in humans. Grading was validated against 2 factors associated with the extent of disk degeneration: type of dog (chondrodystrophic or nonchondrodystrophic breeds) and age. Results—Interobserver and intraobserver agreement for Pfirrmann grading of IVD degeneration were good (κ scores, 0.81 to 0.93). An increase in the extent of disk degeneration was positively correlated with increases in age and with chondrodystrophic breed. Conclusions and Clinical Relevance—The Pfirrmann system was reliably used to grade IVD degeneration in dogs of various breeds and ages. An increase in the extent of IVD degeneration was positively correlated with increases in age and with chondrodystrophic-type dogs.