Enterotoxaemia (pulpy kidney) is a common bacterial disease of sheep caused by Clostridium perfringens type D epsilon toxin. It has mortality rates of up to 30% in non-vaccinated animals. Current vaccines from whole cell cultures are expensive to manufacture and can induce local inflammatory responses in sheep. They usually have reduced immunogenicity because of the difficulty of standardising the inactivation step in vaccine manufacturing. In the current study, we evaluated the safety and potency of a recombinant plant-made epsilon toxoid protein (r-Etox) as an affordable and safer alternative vaccine for developing countries. Results of injection site reactions, rectal temperature and toxin neutralisation test in single and prime-boost inoculations of mice, guinea pigs and sheep suggest that the product is not toxic to animals and could protect sheep against enterotoxaemia.

Sentinel herds and samples submitted by private equine practitioners were used to determine the sero-prevalence and sero-incidence of African horse sickness virus (AHSV) and equine encephalosis virus (EEV) in horse and donkey populations in the Highveld region of Zimbabwe. The sero-prevalence and sero-incidence of antibodies against these viruses were determined using the competitive enzyme-linked immunosorbent assay (ELISA) for the detection of serum antibodies. In donkeys, the median sero-prevalence of AHSV antibodies, across the three rainy seasons under study, was 75% (inter quartile range [IQR] 67-83), with a seasonal median sero-incidence of 45% (IQR 40-63). In horses, the median sero-prevalence of EEV antibodies was 63% (IQR 21-73), with a median seasonal sero-incidence of 10.5% (IQR 10-14), while in donkeys the median sero-prevalence of EEV antibodies was 80% (IQR 67-90), with a median seasonal sero-incidence of 50% (IQR 40-60). This study highlighted the significant levels of exposure of donkeys to AHSV and horses and donkeys to EEV in Zimbabwe despite equine encephalosis remaining unreported by Zimbabwean veterinarians to date. Most seroconversions in sentinel herd animals to AHSV and EEV occurred towards the end of the rainy season in March, April and May corresponding to the time of the year when the Culicoides vectors are in high abundance. In order to determine the clinical significance of these infections, blood and spleen samples, submitted by private equine veterinary practitioners over a 5-year period, from horses showing characteristic clinical signs of African horse sickness were tested for the presence of viral antigen using the antigen capture ELISA. The median sero-prevalence of AHSV antigen in horses recorded from these samples was 38% (IQR 33-88). The predominant AHSV antigen from these samples was serotype 7 (33%) followed by serotype 2 (26%) and serotypes 4 and 8 (16% each). African horse sickness virus serotypes 3 and 9, identified in this study, had not been previously reported in Zimbabwe.

Sentinel herds and samples submitted by private equine practitioners were used to determine the sero-prevalence and sero-incidence of African horse sickness virus (AHSV) and equine encephalosis virus (EEV) in horse and donkey populations in the Highveld region of Zimbabwe. The sero-prevalence and sero-incidence of antibodies against these viruses were determined using the competitive enzyme-linked immunosorbent assay (ELISA) for the detection of serum antibodies. In donkeys, the median sero-prevalence of AHSV antibodies, across the three rainy seasons under study, was 75% (inter quartile range [IQR] 67–83), with a seasonal median sero-incidence of 45% (IQR 40–63). In horses, the median sero-prevalence of EEV antibodies was 63% (IQR 21–73), with a median seasonal sero-incidence of 10.5% (IQR 10–14), while in donkeys the median sero-prevalence of EEV antibodies was 80% (IQR 67–90), with a median seasonal sero-incidence of 50% (IQR 40–60). This study highlighted the significant levels of exposure of donkeys to AHSV and horses and donkeys to EEV in Zimbabwe despite equine encephalosis remaining unreported by Zimbabwean veterinarians to date. Most seroconversions in sentinel herd animals to AHSV and EEV occurred towards the end of the rainy season in March, April and May corresponding to the time of the year when the Culicoides vectors are in high abundance. In order to determine the clinical significance of these infections, blood and spleen samples, submitted by private equine veterinary practitioners over a 5-year period, from horses showing characteristic clinical signs of African horse sickness were tested for the presence of viral antigen using the antigen capture ELISA. The median sero-prevalence of AHSV antigen in horses recorded from these samples was 38% (IQR 33–88). The predominant AHSV antigen from these samples was serotype 7 (33%) followed by serotype 2 (26%) and serotypes 4 and 8 (16% each). African horse sickness virus serotypes 3 and 9, identified in this study, had not been previously reported in Zimbabwe.

Geigeria poisoning in sheep, locally known as 'vermeersiekte', is an economically important plant poisoning in southern Africa. The toxic principles contained by the toxic plants are believed to be several sesquiterpene lactones, such as geigerin, vermeeric acid and vermeerin, which cause striated muscle lesions in small stock. Because of ethical issues surrounding the use of live animals in toxicity studies, there is currently a dire need to establish an in vitro model that can be used to replace traditional animal experimentation. The objective of this study was to determine the cytotoxicity of geigerin in a murine myoblast cell line (C2C12) using methyl-thiazol-tetrazolium (MTT) and lactate dehydrogenase (LDH) assays, annexin V and propidium iodide (PI) flow cytometry and transmission electron microscopy (TEM). Mouse myoblasts were exposed to 2.0 mM, 2.5 mM and 5.0 mM geigerin for 24, 48 and 72 h. A concentration-dependent cytotoxic response was observed. Apoptosis was detected by means of annexin V flow cytometry during the first 24 h and apoptotic bodies were also visible on TEM. According to the LDH and PI flow cytometry results, myoblast cell membranes were not injured. We concluded that the murine myoblast cell line (C2C12) is a suitable model for future studies planned to evaluate the cytotoxicity of other and combinations of sesquiterpene lactones, with and without metabolic activation, implicated in 'vermeersiekte' and to elucidate the subcellular effects of these myotoxins on cultured myoblasts.

Geigeria poisoning in sheep, locally known as ‘vermeersiekte’, is an economically important plant poisoning in southern Africa. The toxic principles contained by the toxic plants are believed to be several sesquiterpene lactones, such as geigerin, vermeeric acid and vermeerin, which cause striated muscle lesions in small stock. Because of ethical issues surrounding the use of live animals in toxicity studies, there is currently a dire need to establish an in vitro model that can be used to replace traditional animal experimentation. The objective of this study was to determine the cytotoxicity of geigerin in a murine myoblast cell line (C2C12) using methyl-thiazol-tetrazolium (MTT) and lactate dehydrogenase (LDH) assays, annexin V and propidium iodide (PI) flow cytometry and transmission electron microscopy (TEM). Mouse myoblasts were exposed to 2.0 mM, 2.5 mM and 5.0 mM geigerin for 24, 48 and 72 h. A concentration-dependent cytotoxic response was observed. Apoptosis was detected by means of annexin V flow cytometry during the first 24 h and apoptotic bodies were also visible on TEM. According to the LDH and PI flow cytometry results, myoblast cell membranes were not injured. We concluded that the murine myoblast cell line (C2C12) is a suitable model for future studies planned to evaluate the cytotoxicity of other and combinations of sesquiterpene lactones, with and without metabolic activation, implicated in ‘vermeersiekte’ and to elucidate the subcellular effects of these myotoxins on cultured myoblasts.

Blood lactate is a predictor of mortality in critically ill humans and animals. Handheld lactate meters have the potential to be used in the field to evaluate the condition of severely injured rhinoceroses but have not been compared with laboratory-based methods. Agreement between a handheld lactate meter and a laboratory method was assessed, as was the stability of rhino blood lactate in the anticoagulant sodium fluoride/potassium oxalate (fluoride/oxalate). Blood samples were obtained from 53 white rhinos that had been immobilised for management reasons. Lactate was measured by means of a handheld meter using whole blood in heparin (WBHEP), whole blood in fluoride/oxalate (WBFO) and fluoride/oxalate plasma (PFO). Results were recorded in both blood (BL) and plasma (PL) modes and compared to an established laboratory method for measuring plasma lactate. To assess the stability of lactate over time, blood lactate in fluoride/oxalate was measured on the handheld meter at intervals for up to 91 h. Agreement was best using WBFO in PL mode, with small bias (−0.16), tight 95% limits of agreement (LOA) (−1.46, 1.14) and a Pc (95% CI) of 0.97 (0.92, 0.99). The agreement was improved for all sample types when using the PL mode compared to the blood lactate (BL) mode. Blood lactate was stable in fluoride/oxalate for 91 h, with a mean change from baseline of 0.15 (−0.178, 0.478) mmol/L (mean, 95% CI). The handheld meter was found to be suitable for field use in white rhinos but provided more reliable results with the device in PL mode. Furthermore, rhino blood lactate was found to be stable in fluoride/oxalate for as long as 3 days.

Since 1982, farmers in the North West province and other parts of South Africa have noticed an increase in the incidence of lameness in cattle. Macro- and microscopical lesions of joints resembled osteochondrosis. Pre-trial data indicated that cattle with osteochondrotic lesions recovered almost completely when fed a supplement containing bio-available micro- and macrominerals of high quality. In the present trial, 43 clinically affected cattle of varying ages (1–5 years) and sexes were randomly divided into three groups. Each group was fed the same commercial supplement base with differing micro- and macromineral concentrations to determine the effect of mineral concentrations on the recovery from osteochondrosis. Both supplements 1 and 2 contained 25% of the recommended National Research Council (NRC) mineral values. Additional phosphate was added to supplement 2. Supplement 3, containing 80% of the NRC mineral values, was used as the control. Results from all three groups indicated no recovery from osteochondrosis. Urine pH of a small sample of the test cattle showed aciduria (pH < 6). Supplement analysis revealed addition of ammonium sulphate that contributed sulphate and nitrogen to the supplement. Supplementary dietary cation anion difference (DCAD) values were negative at -411 mEq/kg, -466 mEq/kg and -467 mEq/kg for supplements 1, 2 and 3, respectively, whereas the pre-trial supplement was calculated at +19.87 mEq/kg. It was hypothesised that feeding a low (negative) DCAD diet will predispose growing cattle to the development of osteochondrosis or exacerbate subclinical or clinical osteochondrosis in cattle.

Since 1982, farmers in the North West province and other parts of South Africa have noticed an increase in the incidence of lameness in cattle. Macro- and microscopical lesions of joints resembled osteochondrosis. Pre-trial data indicated that cattle with osteochondrotic lesions recovered almost completely when fed a supplement containing bio-available micro- and macrominerals of high quality. In the present trial, 43 clinically affected cattle of varying ages (1-5 years) and sexes were randomly divided into three groups. Each group was fed the same commercial supplement base with differing micro- and macromineral concentrations to determine the effect of mineral concentrations on the recovery from osteochondrosis. Both supplements 1 and 2 contained 25% of the recommended National Research Council (NRC) mineral values. Additional phosphate was added to supplement 2. Supplement 3, containing 80% of the NRC mineral values, was used as the control. Results from all three groups indicated no recovery from osteochondrosis. Urine pH of a small sample of the test cattle showed aciduria (pH < 6). Supplement analysis revealed addition of ammonium sulphate that contributed sulphate and nitrogen to the supplement. Supplementary dietary cation anion difference (DCAD) values were negative at -411 mEq/kg, -466 mEq/kg and -467 mEq/kg for supplements 1, 2 and 3, respectively, whereas the pre-trial supplement was calculated at +19.87 mEq/kg. It was hypothesised that feeding a low (negative) DCAD diet will predispose growing cattle to the development of osteochondrosis or exacerbate subclinical or clinical osteochondrosis in cattle.

This study was aimed at the molecular characterisation of bovine papillomavirus type 1 (BPV-1) isolated from papilloma cases in the northwestern region of Turkey. BPV-1 is a widely occurring oncogenic virus in cattle and is associated with benign epithelial neoplasia which causes significant economic losses in dairy and beef cattle because of treatment costs. In this study, 29 suspected papilloma specimens were collected from cattle in northwestern Turkey. These samples underwent molecular characterisation via the polymerase chain reaction (PCR) and sequencing analysis as well as macroscopic and histopathological examination. The histopathological examinations confirmed papilloma as the main lesion type in the specimens. Of the 29 papilloma-like tissue samples that were collected, 11 (i.e. 37.93%) were detected as positive and determined as containing BPV-1 (11 of 11, 100%). Using a partial sequence for the L1 gene acquired from GenBank, phylogenetic analysis confirmed the presence of BPV-1 and revealed that the infection might have originated in cross bred domestic and imported cattle. This study provides potentially useful information on the origin and spread of this disease. Its results can potentially aid in the development of appropriate control measures and therapeutic or vaccination strategies against the BPV-1 strain of bovine papillomatosis.

This study was aimed at the molecular characterisation of bovine papillomavirus type 1 (BPV-1) isolated from papilloma cases in the northwestern region of Turkey. BPV-1 is a widely occurring oncogenic virus in cattle and is associated with benign epithelial neoplasia which causes significant economic losses in dairy and beef cattle because of treatment costs. In this study, 29 suspected papilloma specimens were collected from cattle in northwestern Turkey. These samples underwent molecular characterisation via the polymerase chain reaction (PCR) and sequencing analysis as well as macroscopic and histopathological examination. The histopathological examinations confirmed papilloma as the main lesion type in the specimens. Of the 29 papilloma-like tissue samples that were collected, 11 (i.e. 37.93%) were detected as positive and determined as containing BPV-1 (11 of 11, 100%). Using a partial sequence for the L1 gene acquired from GenBank, phylogenetic analysis confirmed the presence of BPV-1 and revealed that the infection might have originated in cross bred domestic and imported cattle. This study provides potentially useful information on the origin and spread of this disease. Its results can potentially aid in the development of appropriate control measures and therapeutic or vaccination strategies against the BPV-1 strain of bovine papillomatosis.

The objectives of the study were to determine the species composition of ticks infesting white and black rhinoceroses in southern Africa as well as the conservation status of those tick species that prefer rhinos as hosts. Ticks were collected opportunistically from rhinos that had been immobilised for management purposes, and 447 white rhinoceroses (Ceratotherium simum) and 164 black rhinoceroses (Diceros bicornis) were sampled in South Africa, 61 black rhinos in Namibia, 18 white and 12 black rhinos in Zimbabwe, and 24 black rhinos in Zambia. Nineteen tick species were recovered, of which two species, Amblyomma rhinocerotis and Dermacentor rhinocerinus, prefer rhinos as hosts. A. rhinocerotis was collected only in the northeastern KwaZulu-Natal reserves of South Africa and is endangered, while D. rhinocerinus is present in these reserves as well as in the Kruger National Park and surrounding conservancies. Eight of the tick species collected from the rhinos are ornate, and seven species are regularly collected from cattle. The species present on rhinos in the eastern, moister reserves of South Africa were amongst others Amblyomma hebraeum, A. rhinocerotis, D. rhinocerinus, Rhipicephalus maculatus, Rhipicephalus simus and Rhipicephalus zumpti, while those on rhinos in the Karoo and the drier western regions, including Namibia, were the drought-tolerant species, Hyalomma glabrum, Hyalomma rufipes, Hyalomma truncatum and Rhipicephalus gertrudae. The species composition of ticks on rhinoceroses in Zambia differed markedly from those of the other southern African countries in that Amblyomma sparsum, Amblyomma tholloni and Amblyomma variegatum accounted for the majority of infestations.

The objectives of the study were to determine the species composition of ticks infesting white and black rhinoceroses in southern Africa as well as the conservation status of those tick species that prefer rhinos as hosts. Ticks were collected opportunistically from rhinos that had been immobilised for management purposes, and 447 white rhinoceroses (Ceratotherium simum) and 164 black rhinoceroses (Diceros bicornis) were sampled in South Africa, 61 black rhinos in Namibia, 18 white and 12 black rhinos in Zimbabwe, and 24 black rhinos in Zambia. Nineteen tick species were recovered, of which two species, Amblyomma rhinocerotis and Dermacentor rhinocerinus, prefer rhinos as hosts. A. rhinocerotis was collected only in the north-eastern KwaZulu-Natal reserves of South Africa and is endangered, while D. rhinocerinus is present in these reserves as well as in the Kruger National Park and surrounding conservancies. Eight of the tick species collected from the rhinos are ornate, and seven species are regularly collected from cattle. The species present on rhinos in the eastern, moister reserves of South Africa were amongst others Amblyomma hebraeum, A. rhinocerotis, D. rhinocerinus, Rhipicephalus maculatus, Rhipicephalus simus and Rhipicephalus zumpti, while those on rhinos in the Karoo and the drier western regions, including Namibia, were the drought-tolerant species, Hyalomma glabrum, Hyalomma rufipes, Hyalomma truncatum and Rhipicephalus gertrudae. The species composition of ticks on rhinoceroses in Zambia differed markedly from those of the other southern African countries in that Amblyomma sparsum, Amblyomma tholloni and Amblyomma variegatum accounted for the majority of infestations.