The use of haematological techniques to assess fish health is generally accepted. The aim of the current study was to determine selected haematological changes that occur in Clarias gariepinus (Burchell, 1822). infected with trypanosomes. Blood films were prepared according to standard techniques to confirm trypanosome infections and whole blood was collected, the serum and plasma separated, and prepared for albumin and total protein concentration analysis. Plasma albumin levels were significantly higher in infected wild caught fish than in uninfected wild caught fish and uninfected breeding stock. Serum albumin levels were significantly lower in infected wild caught fish when compared to uninfected breeding stock. The total plasma and serum protein levels were within the normal range for C. gariepinus, that is, 3 g – 6 g/100 mL. The total plasma protein levels varied significantly between the three groups. However, the total serum protein levels were only significantly different between uninfected breeding stock and uninfected wild caught fish, as well as uninfected breeding stock and infected wild caught fish. The total protein levels were significantly higher in infected wild caught fish than in the other groups, a possible indication of an infection or inflammatory host response.

The use of haematological techniques to assess fish health is generally accepted. The aim of the current study was to determine selected haematological changes that occur in Clarias gariepinus (Burchell, 1822). infected with trypanosomes. Blood films were prepared according to standard techniques to confirm trypanosome infections and whole blood was collected, the serum and plasma separated, and prepared for albumin and total protein concentration analysis. Plasma albumin levels were significantly higher in infected wild caught fish than in uninfected wild caught fish and uninfected breeding stock. Serum albumin levels were significantly lower in infected wild caught fish when compared to uninfected breeding stock. The total plasma and serum protein levels were within the normal range for C. gariepinus, that is, 3 g – 6 g/100 mL. The total plasma protein levels varied significantly between the three groups. However, the total serum protein levels were only significantly different between uninfected breeding stock and uninfected wild caught fish, as well as uninfected breeding stock and infected wild caught fish. The total protein levels were significantly higher in infected wild caught fish than in the other groups, a possible indication of an infection or inflammatory host response.

In this review, the main gastrointestinal nematodes infecting cattle in Zimbabwe and the epidemiological factors influencing their occurrence are reviewed and discussed. Nineteen gastrointestinal nematode species that belong to seven families have been found to occur in cattle in Zimbabwe. The main genera reported to date are Cooperia, Haemonchus, Trichostrongylus and Oesophagostomumand the dominant species are Cooperia pectinata, Cooperia punctata, Haemonchus placei and Trichostrongylus axei. The mixed infection by several species from the genera is the cause of parasitic gastroenteritis in cattle in Zimbabwe. Production and husbandry practices, season, host age and environment are considered to be the main factors that influence gastrointestinal nematode infection in cattle. The geographical distribution of the gastrointestinal nematodes is also reviewed in relation to the climatic conditions of the country. Various control options are discussed and how they are applicable to the Zimbabwean situation. Based on reports and existing data on the epidemiological features of the gastrointestinal nematode infection in cattle, practical control measures are critically reviewed and recommendations are made for a national control programme.

In this review, the main gastrointestinal nematodes infecting cattle in Zimbabwe and the epidemiological factors influencing their occurrence are reviewed and discussed. Nineteen gastrointestinal nematode species that belong to seven families have been found to occur in cattle in Zimbabwe. The main genera reported to date are Cooperia, Haemonchus, Trichostrongylus and Oesophagostomumand the dominant species are Cooperia pectinata, Cooperia punctata, Haemonchus placei and Trichostrongylus axei. The mixed infection by several species from the genera is the cause of parasitic gastroenteritis in cattle in Zimbabwe. Production and husbandry practices, season, host age and environment are considered to be the main factors that influence gastrointestinal nematode infection in cattle. The geographical distribution of the gastrointestinal nematodes is also reviewed in relation to the climatic conditions of the country. Various control options are discussed and how they are applicable to the Zimbabwean situation. Based on reports and existing data on the epidemiological features of the gastrointestinal nematode infection in cattle, practical control measures are critically reviewed and recommendations are made for a national control programme.

The indirect effects of mastitis treatment are often overlooked in cost-benefit analyses, but it may be beneficial for the dairy industry to consider them. The cost of mastitis treatment may increase when the duration of intra-mammary infections are prolonged due to misdiagnosis of host-adapted mastitis. Laboratory diagnosis of mastitis can be costly and time consuming, therefore cow-side tests such as the California Milk Cell Test (CMCT) and Milk Electrical Resistance (MER) need to be utilised to their full potential. The aim of this study was to determine the relative benefit of using these two tests separately and in parallel. This was done using a partial-budget analysis and a cost-benefit model to estimate the benefits and costs of each respective test and the parallel combination thereof. Quarter milk samples (n= 1860) were taken from eight different dairy herds in South Africa. Milk samples were evaluated by means of the CMCT, hand-held MER meter and cyto-microbiological laboratory analysis. After determining the most appropriate cut-off points for the two cow-side tests, the sensitivity and specificity of the CMCT (Se= 1.00, Sp= 0.66), MER (Se= 0.92, Sp= 0.62) and the tests done in parallel (Se= 1.00, Sp= 0.87) were calculated. The input data that were used for partial-budget analysis and in the cost-benefit model were based on South African figures at the time of the study, and on literature. The total estimated financial benefit of correct diagnosis of host-adapted mastitis per cow for the CMCT, MER and the tests done in parallel was R898.73, R518.70 and R1064.67 respectively. This involved taking the expected benefit of a correct test result per cow, the expected cost of an error per cow and the cost of the test into account. The CMCT was shown to be 11%more beneficial than the MER test, whilst using the tests in parallel was shown to be the most beneficial method for evaluating the mastitis-control programme. Therefore, it is recommended that the combined tests should be used strategically in practice to monitor udder health and promote a pro-active udder health approach when dealing with host-adapted pathogens.

The indirect effects of mastitis treatment are often overlooked in cost-benefit analyses, but it may be beneficial for the dairy industry to consider them. The cost of mastitis treatment may increase when the duration of intra-mammary infections are prolonged due to misdiagnosis of host-adapted mastitis. Laboratory diagnosis of mastitis can be costly and time consuming, therefore cow-side tests such as the California Milk Cell Test (CMCT) and Milk Electrical Resistance (MER) need to be utilised to their full potential. The aim of this study was to determine the relative benefit of using these two tests separately and in parallel. This was done using a partial-budget analysis and a cost-benefit model to estimate the benefits and costs of each respective test and the parallel combination thereof. Quarter milk samples (n= 1860) were taken from eight different dairy herds in South Africa. Milk samples were evaluated by means of the CMCT, hand-held MER meter and cyto-microbiological laboratory analysis. After determining the most appropriate cut-off points for the two cow-side tests, the sensitivity and specificity of the CMCT (Se= 1.00, Sp= 0.66), MER (Se= 0.92, Sp= 0.62) and the tests done in parallel (Se= 1.00, Sp= 0.87) were calculated. The input data that were used for partial-budget analysis and in the cost-benefit model were based on South African figures at the time of the study, and on literature. The total estimated financial benefit of correct diagnosis of host-adapted mastitis per cow for the CMCT, MER and the tests done in parallel was R898.73, R518.70 and R1064.67 respectively. This involved taking the expected benefit of a correct test result per cow, the expected cost of an error per cow and the cost of the test into account. The CMCT was shown to be 11%more beneficial than the MER test, whilst using the tests in parallel was shown to be the most beneficial method for evaluating the mastitis-control programme. Therefore, it is recommended that the combined tests should be used strategically in practice to monitor udder health and promote a pro-active udder health approach when dealing with host-adapted pathogens.

The insulin-like growth factor system (insulin-like growth factor 1, insulin-like growth factor 2, insulin-like growth factor 1 receptor, insulin-like growth factor 2 receptor and six insulin-like growth factor-binding proteins) and insulin are essential to muscle metabolism and most aspects of male and female reproduction. Insulin-like growth factor and insulin play important roles in the regulation of cell growth, differentiation and the maintenance of cell differentiation in mammals. In order to better understand the local factors that regulate equine physiology, such as muscle metabolism and reproduction (e.g., germ cell development and fertilisation), real-time reverse transcription polymerase chain reaction assays for quantification of equine insulin-like growth factor 1 receptor and insulin receptor messenger ribonucleic acid were developed. The assays were sensitive: 192 copies/µLand 891 copies/µL for insulin-like growth factor 1 receptor, messenger ribonucleic acid and insulin receptor respectively (95%limit of detection), and efficient: 1.01 for the insulin-like growth factor 1 receptor assay and 0.95 for the insulin receptor assay. The assays had a broad linear range of detection (seven logs for insulin-like growth factor 1 receptor and six logs for insulin receptor). This allowed for analysis of very small amounts of messenger ribonucleic acid. Low concentrations of both insulin-like growth factor 1 receptor and insulin receptor messenger ribonucleic acid were detected in endometrium, lung and spleen samples, whilst high concentrations were detected in heart, muscle and kidney samples, this was most likely due to the high level of glucose metabolism and glucose utilisation by these tissues. The assays developed for insulin-like growth factor 1 receptor and insulin receptor messenger ribonucleic acid expression have been shown to work on equine tissue and will contribute to the understanding of insulin and insulin-like growth factor 1 receptor physiology in the horse.

The insulin-like growth factor system (insulin-like growth factor 1, insulin-like growth factor 2, insulin-like growth factor 1 receptor, insulin-like growth factor 2 receptor and six insulin-like growth factor-binding proteins) and insulin are essential to muscle metabolism and most aspects of male and female reproduction. Insulin-like growth factor and insulin play important roles in the regulation of cell growth, differentiation and the maintenance of cell differentiation in mammals. In order to better understand the local factors that regulate equine physiology, such as muscle metabolism and reproduction (e.g., germ cell development and fertilisation), real-time reverse transcription polymerase chain reaction assays for quantification of equine insulin-like growth factor 1 receptor and insulin receptor messenger ribonucleic acid were developed. The assays were sensitive: 192 copies/µLand 891 copies/µL for insulin-like growth factor 1 receptor, messenger ribonucleic acid and insulin receptor respectively (95%limit of detection), and efficient: 1.01 for the insulin-like growth factor 1 receptor assay and 0.95 for the insulin receptor assay. The assays had a broad linear range of detection (seven logs for insulin-like growth factor 1 receptor and six logs for insulin receptor). This allowed for analysis of very small amounts of messenger ribonucleic acid. Low concentrations of both insulin-like growth factor 1 receptor and insulin receptor messenger ribonucleic acid were detected in endometrium, lung and spleen samples, whilst high concentrations were detected in heart, muscle and kidney samples, this was most likely due to the high level of glucose metabolism and glucose utilisation by these tissues. The assays developed for insulin-like growth factor 1 receptor and insulin receptor messenger ribonucleic acid expression have been shown to work on equine tissue and will contribute to the understanding of insulin and insulin-like growth factor 1 receptor physiology in the horse.

Several lyssavirus species occur in Africa (Rabies virus, Lagos bat virus, Mokola virus, Duvenhage virus, Shimoni bat virus and Ikoma lyssavirus), displaying a high sequence diversity between isolates belonging to the same species. There is limited information about comparative pathogenesis of these African lyssaviruses and this precludes authoritative opinion on the potential public and veterinary health impact. In this study, an analysis of representative African lyssaviruses attempted to correlate viral genomic sequence similarities and differences with the corresponding pathogenic profiles observed in mice. The study demonstrated that the virus isolates evaluated could be lethal to mice when introduced intramuscularly and that different isolates of the same lyssavirus species differ in their virulence. Using real-time polymerase chain reaction (PCR), viral RNA was detected in brain tissue, but no viral RNA was detected in the salivary glands or blood of mice that succumbed to infection. Comparison of known pathogenic domains indicated that pathogenicity is likely to be dependent on multiple domains. Cumulatively, our results re-emphasised the realisation that the pathogenicity of a lyssavirus species cannot be deduced based on studies of only a single isolate of the species or a single pathogenic domain.

Several lyssavirus species occur in Africa (Rabies virus, Lagos bat virus, Mokola virus, Duvenhage virus, Shimoni bat virus and Ikoma lyssavirus), displaying a high sequence diversity between isolates belonging to the same species. There is limited information about comparative pathogenesis of these African lyssaviruses and this precludes authoritative opinion on the potential public and veterinary health impact. In this study, an analysis of representative African lyssaviruses attempted to correlate viral genomic sequence similarities and differences with the corresponding pathogenic profiles observed in mice. The study demonstrated that the virus isolates evaluated could be lethal to mice when introduced intramuscularly and that different isolates of the same lyssavirus species differ in their virulence. Using real-time polymerase chain reaction (PCR), viral RNA was detected in brain tissue, but no viral RNA was detected in the salivary glands or blood of mice that succumbed to infection. Comparison of known pathogenic domains indicated that pathogenicity is likely to be dependent on multiple domains. Cumulatively, our results re-emphasised the realisation that the pathogenicity of a lyssavirus species cannot be deduced based on studies of only a single isolate of the species or a single pathogenic domain.

The study aimed to determine the prevalence of peste des petits ruminants in the arid zone (Niamey, Tillabéry and Tahoua) of the Republic of Niger. A serological survey was conducted and 519 serum samples were collected from 253 unvaccinated sheep and 266 unvaccinated goats. The sample included 340 female animals (168 sheep and 172 goats) and 160 kids and lambs (78 lambs and 82 kids). A competitive enzyme-linked immunosorbent assay yielded an overall seroprevalence of 45.0%. The prevalence in sheep was 42.0% compared with 47.9% in goats. The seroprevalence observed amongst small ruminants in Tahoua (49.8%) and Tillabéry (46.6%) was significantly higher (p = 0.001) than that observed in animals from Niamey (25.1%). It was also higher (p = 0.04) in sheep younger than two years (51.8%) than in adults (37.6%). Conversely, the seroprevalence showed no significant difference between male animals (35.8% in sheep; 50.1% in goats) and female animals (45.1% in sheep; 46.4% in goats). The prevalence of the disease observed amongst the sheep and goat populations confirms the continued danger of this disease in the areas studied. It is therefore necessary to develop strategies such as improving livestock services, providing effective vaccines and implementing a vaccination programme for an effective control of the disease in sub-Saharan Africa.

The study aimed to determine the prevalence of peste des petits ruminants in the arid zone (Niamey, Tillabéry and Tahoua) of the Republic of Niger. A serological survey was conducted and 519 serum samples were collected from 253 unvaccinated sheep and 266 unvaccinated goats. The sample included 340 female animals (168 sheep and 172 goats) and 160 kids and lambs (78 lambs and 82 kids). A competitive enzyme-linked immunosorbent assay yielded an overall seroprevalence of 45.0%. The prevalence in sheep was 42.0% compared with 47.9% in goats. The seroprevalence observed amongst small ruminants in Tahoua (49.8%) and Tillabéry (46.6%) was significantly higher (p = 0.001) than that observed in animals from Niamey (25.1%). It was also higher (p = 0.04) in sheep younger than two years (51.8%) than in adults (37.6%). Conversely, the seroprevalence showed no significant difference between male animals (35.8% in sheep; 50.1% in goats) and female animals (45.1% in sheep; 46.4% in goats). The prevalence of the disease observed amongst the sheep and goat populations confirms the continued danger of this disease in the areas studied. It is therefore necessary to develop strategies such as improving livestock services, providing effective vaccines and implementing a vaccination programme for an effective control of the disease in sub-Saharan Africa.

Several outbreaks of Rift Valley fever (RVF) have been documented in South Africa since it first occurred in the country in 1950. However, there is no comprehensive account of the timing, location and extent of all known outbreaks. As part of a study investigating the epidemiology of RVF in South Africa, a full history of outbreaks was compiled using references to the disease in South Africa from scientific literature, annual reports, disease reports and animal disease databases. The geographic location and temporal occurrence of each outbreak were recorded as accurately as allowed by the available records. The result was a better and more complete picture than has hitherto been available of the spatial and temporal distribution of RVF in South Africa for the period between 1950 and 2011. Several smaller outbreaks which had not been described previously in literature were documented. Extensive outbreaks occurred in the central interior of the country (Free State, Eastern Cape and Northern Cape provinces), interspersed with smaller outbreaks or long intervening periods of absence, whilst smaller outbreaks occurred in the eastern part of the country (KwaZulu-Natal, Mpumalanga and Gauteng).

Several outbreaks of Rift Valley fever (RVF) have been documented in South Africa since it first occurred in the country in 1950. However, there is no comprehensive account of the timing, location and extent of all known outbreaks. As part of a study investigating the epidemiology of RVF in South Africa, a full history of outbreaks was compiled using references to the disease in South Africa from scientific literature, annual reports, disease reports and animal disease databases. The geographic location and temporal occurrence of each outbreak were recorded as accurately as allowed by the available records. The result was a better and more complete picture than has hitherto been available of the spatial and temporal distribution of RVF in South Africa for the period between 1950 and 2011. Several smaller outbreaks which had not been described previously in literature were documented. Extensive outbreaks occurred in the central interior of the country (Free State, Eastern Cape and Northern Cape provinces), interspersed with smaller outbreaks or long intervening periods of absence, whilst smaller outbreaks occurred in the eastern part of the country (KwaZulu-Natal, Mpumalanga and Gauteng).

Bovine tuberculosis is an important zoonosis and accurate diagnosis is important for its surveillance. Post-mortem diagnosis may, however, be compromised by lesions caused by other pathogens. In an investigation on its prevalence in slaughter cattle in Kenya, Mycobacterium bovis and dimorphic fungi were inadvertently identified separately or concurrently in tuberculous lesions. Beef carcasses were inspected for lesions in two abattoirs in Nairobi. Tissues with lesions were collected and transported to the laboratory. Smears of lesions were stained by acid-fast procedure and examined microscopically. Lesions were cultured in Löwenstein-Jensen (LJ) and in BBL TM Mycobacterium growth indicator tubes (MGIT) media. Mycobacteria isolates in LJ medium were identified by DNA typing. Smears of BBLTM MGIT cultures were acid-fast stained and examined microscopically. Tissue sections were stained with periodic acid-Schiff reagent before examination. Of the 929 carcasses examined, 176 had granulomatous lesions. Dimorphic fungi were detected as acid-fast negative cells in 58 (32.9; 33.5%) of the lesion smears, either alone (29.0; 16.4%) or concurrently with acid-fast bacilli (29.0; 16.4%). The fungi were also detected in some BBL TM MGIT-culturesmears and lesioned tissue sections. The fungi were identified, by means of cellular morphology, as Paracoccidioides brasiliensis and Blastomyces dermatitidis. A total of 64 isolates of mycobacteria were recovered in LJ medium, 19 of which were identified as M. bovis. The present report documents native P. brasiliensis infections outside the presumed endemic region and B. dermatitidis infections in a livestock animal. The findings further indicate the importance of dimorphic fungi as a differential diagnosis of bovine tuberculosis in the region.

Bovine tuberculosis is an important zoonosis and accurate diagnosis is important for its surveillance. Post-mortem diagnosis may, however, be compromised by lesions caused by other pathogens. In an investigation on its prevalence in slaughter cattle in Kenya, Mycobacterium bovis and dimorphic fungi were inadvertently identified separately or concurrently in tuberculous lesions. Beef carcasses were inspected for lesions in two abattoirs in Nairobi. Tissues with lesions were collected and transported to the laboratory. Smears of lesions were stained by acid-fast procedure and examined microscopically. Lesions were cultured in Löwenstein-Jensen (LJ) and in BBL TM Mycobacterium growth indicator tubes (MGIT) media. Mycobacteria isolates in LJ medium were identified by DNA typing. Smears of BBLTM MGIT cultures were acid-fast stained and examined microscopically. Tissue sections were stained with periodic acid-Schiff reagent before examination. Of the 929 carcasses examined, 176 had granulomatous lesions. Dimorphic fungi were detected as acid-fast negative cells in 58 (32.9; 33.5%) of the lesion smears, either alone (29.0; 16.4%) or concurrently with acid-fast bacilli (29.0; 16.4%). The fungi were also detected in some BBL TM MGIT-culturesmears and lesioned tissue sections. The fungi were identified, by means of cellular morphology, as Paracoccidioides brasiliensis and Blastomyces dermatitidis. A total of 64 isolates of mycobacteria were recovered in LJ medium, 19 of which were identified as M. bovis. The present report documents native P. brasiliensis infections outside the presumed endemic region and B. dermatitidis infections in a livestock animal. The findings further indicate the importance of dimorphic fungi as a differential diagnosis of bovine tuberculosis in the region.

The distribution of interstitial cells of Cajal (ICC), the probable pacemakers in gastrointestinal motility, was investigated using an antigenic marker of gastric ICC known as C-Kit. Antiserum raised against the general neuronal marker protein gene peptide 9.5 (PGP) as well as the nitrergic neuronal marker neuronal nitric oxide synthase (nNOS) were used to investigate the distribution of gastric nerves. Polyclonal goat anti-human C-Kit was reliable in labelling ICC in the stomach. Two classes of ICC were identified according to their distribution: ICC-MY distributed around the periphery of myenteric ganglia and ICC-IM in the circular and longitudinal muscle layers. The neuronal marker PGP was reliably consistent in revealing the density and distribution of the enteric nervous system. Density of nerve fibres was higher in circular smooth muscle than in longitudinal smooth muscle. From nNOS immunohistochemistry, it is evident that inhibitory (nitrergic) nerves constitute a substantial fraction of the enteric nervous system.

The distribution of interstitial cells of Cajal (ICC), the probable pacemakers in gastrointestinal motility, was investigated using an antigenic marker of gastric ICC known as C-Kit. Antiserum raised against the general neuronal marker protein gene peptide 9.5 (PGP) as well as the nitrergic neuronal marker neuronal nitric oxide synthase (nNOS) were used to investigate the distribution of gastric nerves. Polyclonal goat anti-human C-Kit was reliable in labelling ICC in the stomach. Two classes of ICC were identified according to their distribution: ICC-MY distributed around the periphery of myenteric ganglia and ICC-IM in the circular and longitudinal muscle layers. The neuronal marker PGP was reliably consistent in revealing the density and distribution of the enteric nervous system. Density of nerve fibres was higher in circular smooth muscle than in longitudinal smooth muscle. From nNOS immunohistochemistry, it is evident that inhibitory (nitrergic) nerves constitute a substantial fraction of the enteric nervous system.