Research Articles (Production Animal Studies)

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Biochemical and haemostatic variables associated with metastasis in dogs with carcinoma or sarcoma
Pazzi, Paolo; Fosgate, Geoffrey Theodore; Kristensen, Annemarie T.; Goddard, Amelia (Wiley, 2026-01)
OBJECTIVES : Identify alterations in biochemical and haemostatic variables between tumour-bearing dogs with and without metastasis that can be used to predict the presence of metastasis. MATERIALS AND METHODS : Thirty dogs with sarcoma and 29 with carcinoma were included in the analysis. Serum biochemistry profiles and haemostatic variables (haematocrit value, platelet count, thromboelastography (TEG), fibrinogen, Factor X, VII, antithrombin activity and D-dimer concentration) were measured for all dogs. All dogs underwent complete post-mortem and histopathological evaluations. For tumour-bearing dogs without intracavitary haemorrhage, measured variables were compared between dogs with and without metastasis, and univariate and multivariable analysis were performed to identify predictors of metastasis. RESULTS : Metastasis was identified in 31 of 59 (53%) dogs, of which 5 of 31 (16%) had metastasis to the regional lymph node only and 26 of 31 (84%) had distant metastasis. Sodium, ionised calcium, TEG lysis % at 30 and 60 minutes (Ly60) were significantly lower in tumour-bearing dogs without intracavitary haemorrhage with metastasis compared to dogs without metastasis. Multivariable analysis identified sodium <142.5 mmol/L as 64% sensitive (CI95%:45% to 82%) and 63% specific (CI95%:44% to 81%); and Ly60 < 1.0% as 68% sensitive (CI95%: 49% to 88%) and 78% specific (CI95%:61% to 95%) for prediction of the presence of metastasis. Parallel interpretation of lower sodium and decreased Ly60 resulted in high sensitivity (96%) for the presence of metastasis. CLINICAL SIGNIFICANCE : Sodium and TEG-based decreased fibrinolysis were associated with metastasis in tumour-bearing dogs without haemorrhage; when identified, they should prompt further diagnostics to detect possible metastasis of a primary carcinoma or sarcoma.
Mosquitoes then and now : culicine mosquito research in and around Ndumo Game Reserve, KwaZulu-Natal
Thompson, P.N. (Peter N.); Guarido, Milehna M.; Kemp, Alan (Southern African Wildlife Management Association, 2025-02)
The exceptional biodiversity of the Ndumo area and Maputaland in general, with its tropical biota, is reflected in the high diversity of culicine mosquitoes occurring in the area and, along with their vectors, a high diversity of arthropod-borne viruses (arboviruses). Research interest in the area was driven by the need to identify risks associated with the occurrence of arboviruses potentially affecting human and livestock health in the area, as well as the risk of introduction of arboviruses from elsewhere. We give an overview of the mosquito and arbovirus-related research that has taken place at Ndumo and elsewhere along the lower Phongolo River floodplain since the first expedition in 1955. Intensive work was done on mosquitoes and arboviruses for about 15 years, after which a period of 45 years saw only one focused mosquito study (1989-1993). More recently, interest was inspired once again by the threat of emerging and re-emerging arboviruses and we have been studying culicine mosquitoes and their associated viruses in the Ndumo area since 2016. We describe our recent findings with respect to occurrence and abundance of culicine mosquito species, compare them to historical findings, discuss possible reasons for apparent changes observed, and propose priorities for future research in the area.
Detection and molecular characterization of Listeria monocytogenes and Listeria spp. isolates recovered from cattle farms in Mpumalanga Province, South Africa
Moabelo, Khomotso Confidence; Gcebe, Nomakorinte; Gana, James; Ngoshe, Yusuf Bitrus; Moerane, Rebone; Adesiyun, Abiodun Adewale (Wiley, 2025-12)
This study determined the prevalence, characteristics and factors associated with isolating L. monocytogenes and other Listeria species (Listeria spp.) from samples collected from cattle farms in Mpumalanga province, South Africa. A total of 475 samples comprising fresh faeces, pooled environmental faeces, silage, feeds and water were collected from 25 farms (feedlot, cow–calf operations and communal) in three districts (Bronkhorstspruit, Emalahleni and Middleburg). Standard bacteriological and molecular assays were used to isolate, identify and characterize Listeria isolates. The prevalence of L. monocytogenes and other Listeria spp. in farm samples was 2.5% (12/475) and 9.2% (44/475) (p < 0.05), respectively. The highest prevalence of isolation of L. monocytogenes and Listeria spp. was 5.9% (5/85) and 16.7% (5/30) in faeces and silage, respectively. Farm size was the only factor significantly (p < 0.05) associated with detecting L. monocytogenes; the only serotype detected was 1/2a, and all the isolates were positive for virulence genes hlyA and inlJ. The overall prevalence of L. monocytogenes in samples collected from cattle farms (2.5%) across the province, the detection of serotype 1/2a associated with human listeriosis and the positivity of all strains for one or more virulent genes all pose significant public health and food safety risks from the sources assessed. There is a need to implement measures to reduce or eliminate carriage or contamination by L. monocytogenes on cattle farms to avoid the entry of the pathogen into the human food chain in South Africa.
Prevalence, molecular profile and antibiotic resistance of Listeria species in retail beef products in North-West Province, South Africa : a cross-sectional analysis
Mtshali, Nduduzo C.; Gcebe, Nomakorinte; Moerane, Rebone; Adesiyun, Abiodun Adewale (Wiley, 2025-11)
This cross-sectional study determined the occurrence, distribution, molecular characteristics and antibiograms of Listeria species recovered from beef and beef products retailed in the North-West Province, South Africa. The study also investigated the factors associated with the contamination of these products by Listeria spp. and their characteristics. Conventional methods and polymerase chain reaction (PCR) were employed to detect and characterize the isolates of Listeria spp. In contrast, the disc diffusion method was used to determine their susceptibility to 16 antimicrobial agents. Four hundred beef products were randomly collected from 30 retail outlets across the North-West Province. The prevalence of Listeria monocytogenes and other Listeria spp. was 6% (24/400) and 30.5% (122/400), respectively (p < 0.001). Of the five variables (district, size of outlet, type of beef and beef products, product display temperature and types of presentation), only the type of beef and beef products had a statistically significant (p = 0.034) effect on the occurrence of L. monocytogenes. In contrast, none had any significant effect on other Listeria spp. Among the 24 isolates of L. monocytogenes, all five serogroups assayed were detected, with the predominant ones being IIb (45.8%), IVb (20.8%) and IIa (20.8%). All eight virulence genes assayed were detected, with actA (50%), inlB (45.8%) and inlA (41.7%) being the most frequently detected. All isolates of L. monocytogenes (n = 24) and other Listeria spp. (n = 122) were resistant to one or more of the 16 antimicrobial agents tested. For L. monocytogenes isolates, resistance was high to nalidixic acid (100%), enrofloxacin (41.7%) and cefoxitin (37.5%) but low to clindamycin (8.3%) and sulphamethoxazole-trimethoprim (8.3%). The frequency of multi-drug resistance (MDR) in the L. monocytogenes isolates was 95.8% (23/24). Our study reveals the risk of human listeriosis in consumers of beef and beef products contaminated by virulent and antimicrobial-resistant serogroups of L. monocytogenes in the North-West Province of South Africa.
Technical aspects of improved semen collection procedures in African rhinoceroses (Ceratotherium simum; Diceros bicornis) under field conditions
Meuffels-Barkas, Janine; Luther-Binoir, I.; Bertschinger, Hendrik Jan; Callealta, I.; Tindall, B.; Lueders, I. (Medpharm Publications, 2025-11)
Wild rhinoceros populations are threatened by ongoing poaching pressure and habitat loss. Establishing reservoirs of gametes of as many individuals as possible may assist to preserve genetic diversity and could be applied in assisted reproductive techniques in the future. However, for routine implementation of semen collection during any male rhinoceros immobilisation event, current methods and protocols need simplification and improvement. This study aimed to establish field-friendly methods of semen collection in white (Ceratotherium simum; WR) and black rhinoceroses (Diceros bicornis; BR) that can be performed opportunistically given the usual time constraints. Sixty-two game-farmed WR and seven wild BR were immobilised for planned management interventions. Semen collection was performed using electro-stimulation with a battery powered electro-ejaculator and specifically designed rectal probe. Furthermore, in ten WR and two BR, urethral catheterisation was performed with a 10FG nasogastric tube passed retrograde up the urethra as a method of semen collection. Semen-rich fractions were collected from 47/62 WR and 6/7 BR following electro-stimulation. Of these, 10 WR and two BR samples were obtained by urethral catheterisation. The duration of semen collection was 16.4 ± 7.3 (3–30) and 25.8 ± 6.0 (19–33) min requiring 5.2 ± 2.3 and 6.0 ± 0.7 stimulation sets for WR and BR, respectively. Semen volumes, sperm concentrations, motile and viable sperm were 1–64 and 9–18 ml, 68.4 ± 54.2 and 23.7 ± 26.7x106/ml, 51.0 ± 14.2 and 55.0 ± 17.3, and 79.9 ± 15.0 and 88.3 ± 8.4% for WR and BR, respectively. Urethral catheterisation, when implemented, reduced the time required for semen collection. Operator experience influenced sampling efficacy. Equipment and methods described in this study improved semen collection in free-ranging rhinoceroses and can be combined with routine immobilisations, despite time constraints.
A systematic review of the role of laboratory animal veterinarians in promoting One Welfare
Chipangura, John Kudakwashe; Kanengoni, Arnold Tapera; Nederlof, Remco A.; Bakker, Jaco; Naidoo, Vinny (Sage, 2026-01)
One Welfare is an emerging concept that seeks to integrate the welfare of animals, humans and the environment. This systematic review examines the role of laboratory animal veterinarians in promoting One Welfare within the context of animal use for scientific research. By analysing 65 publications, we explored the diverse roles of laboratory animal veterinarians in advancing animal welfare, supporting human health and promoting environmental sustainability. The reviewed literature described veterinarians’ involvement in areas such as animal welfare oversight, implementation of the Three Rs principles, regulatory compliance and ethical review processes. Several themes emerged that are related to the One Welfare framework, namely: veterinary oversight, welfare assessment and implementation, emotional wellbeing, professional support, and contribution to education and training. The literature highlights the potential need for specialised training in laboratory animal medicine, and outlines the challenges veterinarians encounter regarding ethical considerations and cognitive dissonance in research environments. Based on the identified gaps, we propose measures to reinforce the principles of One Welfare, including interdisciplinary collaboration and the adoption of strategies to safeguard the environment (e.g. the use of composting for minimally-infectious waste and digesters for high-impact waste). Additionally, we recommend establishing institutional sustainability committees to oversee governance and resource management across research institutions.
Increasing targeted poaching of lions for trade has the potential to pose an existential threat to the species in Africa
Lindsey, Peter Andrew; Nicholson, Samantha K.; Coals, Peter G.R.; Taylor, William Andrew; Becker, Matthew Smith; Rademeyer, Kerri; Briers-Louw, Willem Daniel; Almeida, João S.; Chase, Michael J.; Dore, Ashleigh; Henschel, Philipp H.; Kwiyega, Jonathan Lucas; Loveridge, Andrew J.; Mandisodza-Chikerema, Roseline L.; Mandinyenya, Bob R.; Nampindo, Simon; Roodbol, Marnu; Whittington-Jones, Gareth M.; Uiseb, Kenneth Heinrich; Naude, Vincent N.; Williams, Vivienne Linda (Wiley, 2026-01)
Lions (Panthera leo) in Africa are targeted for the illegal wildlife trade, driven by demand in African and Asian markets, for their body parts. This threat is distinct from traditional drivers of lion decline such as prey depletion, habitat loss, and persecution and is poorly understood, underreported, growing, and prone to the influence of organized transnational crime. Here, we synthesize the current state of knowledge on targeted poaching for lion parts, identify key conservation and legal challenges, and propose a coordinated response agenda, drawing on examples from around the continent. We call for consideration in six critical areas: improving in situ protection, effective engagement of communities in conservation interventions, improved understanding of trade dynamics, disrupting the trade via multiple mechanisms, strengthening legal frameworks, and demand reduction. We recommend a proactive approach to prevent entrenchment of poaching and illicit markets and avert severe impacts on lion populations. Without coordinated action to address targeted poaching, there is a significant risk of lion population declines and extirpations. Urgent action is needed to acknowledge and address this issue, because it represents a potentially existential threat to the species.
Digestibility, passage rate, growth, and digesta properties in Windsnyer pigs fed increasing potato hash silage
Ncobela, Cyprial Ndumiso; Kanengoni, Arnold Tapera; Chimonyo, Michael (MDPI, 2025-12-15)
The study was conducted to determine the apparent total tract digestibility, the rate of digesta passage, growth performance, and physicochemical properties of the digesta of Windsnyer pigs fed on increasing levels of potato hash silage. Diets were formulated to contain 0, 80, 160, 240, 320, and 400 g potato hash silage/kg of diet. Pigs were randomly assigned to six diets according to a completely randomised design. Six pigs were allocated to each dietary treatment. All diets were blended with chromic oxide (Cr2O3) to calculate apparent total tract digestibility and rate of passage. Pigs were fed diets containing different levels of potato hash silage for 5 d, following 7 d of adaptation. Thereafter, pigs were subjected to a 35-day growth performance experiment. Thirty-six pigs were slaughtered and eviscerated to determine digesta characteristics and gut compartment weights. There was a positive correlation (p < 0.05) between mean retention time and each of digestibility of dry matter, organic matter, and crude protein. There was a quadratic increase (p < 0.05) in digestibility of organic matter, crude protein, fibre and feed intake as dietary levels of potato hash silage increased. Average daily gain and gain-to-feed ratio decreased linearly (p < 0.05) in pigs as levels of potato hash silage increased. The swelling capacity (SWC) of the digesta from ileum decreased linearly (p < 0.05) as dietary levels of potato hash silage increased. The SWC of the digesta from the caecum increased linearly (p < 0.05) as dietary levels of potato hash silage increased. The water holding capacity (WHC) of the stomach digesta decreased linearly (p < 0.05) as dietary levels of potato hash silage increased. The WHC of the digesta from the ileum and caecum displayed negative quadratic responses (p < 0.05) as dietary levels of potato hash silage increased. The WHC of digesta from the proximal colon showed a linear decline (p < 0.05) as dietary levels of potato hash silage increased. The WHC of digesta from the distal colon increased linearly (p < 0.05) as dietary levels of potato hash silage increased. The results indicated that Windsnyer pigs can effectively utilise potato hash silage in diets until the 240 g/kg inclusion level beyond which total tract digestibility and feed intake are compromised.
Systematic review and meta-analysis of fertility outcome following in vivo insemination with sex-sorted semen in sheep
Nel, J.G.; Thompson, P.N. (Peter N.); Holm, Dietmar Erik (Medpharm Publications, 2025-02)
BACKGROUND : Sex-sorted semen (SS) offers economic benefits to sheep producers, but lower fertility outcome (FO), defined as probability of pregnancy, pregnancy rate or lambing rate, than that following conventional semen (CS) artificial insemination (AI) may limit its use OBJECTIVES : To systematically review the literature, and analyse factors associated with FO following AI in sheep using SS vs CS. METHODS : Available literature was searched using the PRISMA guidelines, resulting in 11 studies with 14 experiments that were reviewed. From these, information from 70 study cohorts representing 13 experiments was used to conduct a meta-analysis which confirmed that FOs for SS and CS AI were 37% (95% CI = 31-43%) and 52% (95% CI = 45-59%), respectively (p < 0.01). RESULTS : FO improved over time, with FO following SS and CS AI improving at the same rate over the period investigated (19972022). In a subgroup analysis, five factors were identified that potentially decrease the FO after SS AI disproportionately. These were sperm dose < 4 χ106 spermatozoa, semen preservation (fresh vs frozen-thawed), oestrus synchronisation using an intravaginal sponge (vs a controlled internal drug release device), presence of gonadotropin-releasing hormone in the synchronisation protocol, and absence of biostimulation using a teaser ram. In a random-effects model analysis, an interaction between sperm dose and SS vs CS, and semen preservation were independent predictors of FO after adjusting for the effect of timing of insemination. CONCLUSION : FO following insemination with SS is 15% lower than that of CS, which can be narrowed by increasing the semen dose for SS inseminations and improving the synchronisation of ovulation with the timing of insemination.
Localized Rift Valley fever virus persistence explains epidemic and interepidemic dynamics and guides control strategies
Rostal, Melinda K.; Prentice, Jamie C.; Ross, Noam; Kemp, Alan; Thompson, Peter N.; Anyamba, Assaf; Cleaveland, Sarah; Cordel, Claudia; Msimang, Veerle; Jansen van Vuren, Petrus; Haydon, Daniel T.; Karesh, William B.; Paweska, Janusz T.; Matthews, Louise (The Royal Society, 2025-07)
Rift Valley fever (RVF) is an emerging disease with devastating impacts on livestock health and livelihoods. The risk of RVF virus (RVFV) emergence in new regions and the effectiveness of a strategy for preventing establishment are impacted by how infection persists at local scales. Multiple mechanisms have been proposed for its persistence in regions prone to epidemics, including maintenance via transovarial transmission (TOT) but whether and how TOT can support local persistence is not well understood. Through the development of host- and multi-vector climate-driven simulation models to recreate observed patterns of prevalence and outbreak frequency, we show that TOT has the potential to play an important role in local persistence through seasonal cold or dry periods. Local persistence required annual low-level transmission of RVFV concurrently with substantial TOT, whereas the infrequent large outbreaks hampered long-term persistence in our simulations. We show that under this mode of local persistence, large outbreaks can be prevented with low-level vaccination, but that the long-term local persistence can only be interrupted with many years of sustained vaccination. Determining the role of TOT in persistence is critical for designing countermeasures to prevent establishment after emergence.
Quantification of the incidence and financial implications of stock theft in Eastern Cape Province, South Africa
Ndzungu, Kanya; Ngoshe, Yusuf Bitrus; Jaja, Ishmael Festus (Springer, 2025-09)
Stock theft poses a significant and persistent challenge to the agricultural sector in South Africa. This widespread issue has severe consequences for farmers, including financial losses, emotional distress, and the inability to maintain sustainable agricultural practices. The objective of the study was to quantify the incidence and financial implications of stock theft in Eastern Cape Province (ECP), South Africa. The retrospective data (2018 to 2024) of stock theft was obtained from the provincial police stock theft unit, captured in Excel, transformed, and analysed using R Studio 4.2.2 (version 2022) for statistical analysis. The Alfred Nzo district, with a total of 6427 (21.5%) reported cases, experienced the highest number of cases of stock theft reported amongst the eight districts of the ECP in the period from 2018 to 2024 financial year. Sheep (OR = 1.03; P < 0.01) and goat (Odds Ratio = 1.00; P > 0.40) had a higher likelihood of being stolen, and with no recoveries after being stolen (Odds Ratio = 0.99; P > 0.93) and (Odds Ratio = 1.01; P > 0.119). In the current study, cattle amounted to a loss of 399 million rands (21,904,418.00 USD), with 30,816 cattle being stolen. The impact of stock theft has far-reaching ramifications for the country’s economy and the sustainability of current farming ventures. Information obtained from this study could assist stakeholders in being empowered to make informed decisions, allocate resources effectively, and develop targeted interventions to combat stock theft.
Avian influenza situation report —Africa
Abolnik, Celia (Canadian Science Publishing, 2025-11)
Africa's vast geographic and climatic diversity makes it a critical region for the ecology and spread of avian influenza viruses, particularly due to its role as a wintering ground for Palearctic migratory waterbirds. The continent has experienced multiple waves of clade 2.3.4.4b A/H5Nx high pathogenicity avian influenza (HPAI), which has caused widespread outbreaks in poultry and wild birds since 2017. From 2023 to mid-2025, clade 2.3.4.4b A/H5N1 outbreaks were reported across West and Southern Africa, with severe impacts on poultry production and conservation of endangered wild bird species. Concurrently, South Africa and Mozambique battled an unprecedented A/H7N6 HPAI epizootic in 2023, leading to the culling or loss of over 6.8 million chickens. Additionally, the A/H9N2 subtype, particularly G5.5 sublineage strains, continues to circulate in North, West, and East Africa, with reassortant viruses with A/H5Nx viruses reported in Egypt. Underreporting and limited surveillance hamper accurate epidemiological assessment. Despite these challenges, advancements in noninvasive environmental sampling offer promising tools for early detection. Strengthening regional cooperation and surveillance is essential for mitigating future outbreaks and protecting both animal and public health.
Monitoring, surveillance, antimicrobial resistance and genetic diversity analysis of non-typhoidal Salmonella in South Africa from 1960–2023 from animal and animal products
Matle, Itumeleng; Pfukenyi, Davies Mubika; Maphori, Nozipho; Moatshe, Nkagiseng; Nkabinde, Thabo; Motaung, Annah; Schmidt, Tracy; Seakamela, Emmanuel; Mwanza, Mulunda; Ngoma, Lubanza; Sirdar, Mohamed Mahmoud; Mbatha, Khanyisile R.; Magwedere, Kudakwashe (Public Library of Science, 2025-08-01)
Salmonellosis remains one of the most frequently reported foodborne diseases globally, with the highest burden in low-resource areas. The millions of deaths caused by Nontyphoidal Salmonella (NTS) infections emphasize the urgent need for timely, detailed, and evidence-based interventions to effectively manage and monitor NTS burdens. This study retrospectively analyzed 1,028 NTS isolates from animals, the environment, and food products in South Africa, collected between 1960 and 2023. Among the 102 serotypes identified, S. Heidelberg, isolated only between 2000−2009 and 2020−2023, accounted for 94.3% of isolations during the latter period, suggesting a recent shift in Salmonella epidemiology in the region. The highest resistance rates were observed for cefoxitin (65.7%), cephalothin (62.8%), and tetracycline (59.8%), with a significant increase in resistance to several antibiotics, including ceftriaxone and aztreonam, from 2010−2023. Genetic analysis revealed that S. Gallinarium had the highest prevalence of antibiotic resistance genes, such as tetA (71.4%), qnrA (64.3%), cat1 (64.3%), blaPSE (57.1%), and both blaCMY-2 and qnrB at 50%. The blaPSE and blaSHV genes were strongly associated with ceftriaxone resistance in S. Dublin isolates, while blaPSE and qnrS were linked to chloramphenicol resistance in S. Enteritidis and S. Dublin isolates. Additionally, 87% of the virulence genes screened were present in over 50% of the serotypes, indicating increased adaptability and potential shifts in disease dynamics. The rise in antimicrobial resistance, driven by antimicrobial misuse, horizontal gene transfer, and biofilm formation, could alter serotype dynamics and changing disease epidemiology. This trend underscores the urgent need for effective antimicrobial stewardship and surveillance to combat the spread of antibiotic resistance in Salmonella populations.
Does cooling affect skeletal muscle glycogen replenishment after an acute bout of fear-induced exertional hyperthermia in blesbok (Damaliscus pygargus phillipsi)?
Kohn, Tertius Abraham; Martin, Mahmooda; Van Boom, Kathryn Merle; Donaldson, Byron; Blackhurst, Dee M.; Fitte, Agustina; Burroughs, Richard; Steyl, Johan Christian Abraham; Goddard, Amelia; Meyer, Leith Carl Rodney (Elsevier, 2025-11)
Rhabdomyolyses is a clinical sign of capture myopathy in wild animals and may be linked to glycogen metabolism. To study potential mechanisms, 26 wild blesbok were chased for 15 min and immobilised, whereafter 12 of these blesbok were doused with ice-water (n = 14 chased only group; n = 12 chased + cooled group). An additional 12 blesbok served as resting (not chased) uncooled controls. Vastus lateralis biopsies were obtained after immobilisation for biochemical analyses. Biopsies obtained at initial capture, 3- and 16-days post exercise were analysed for glycogen content. Blesbok muscles contained predominantly myosin heavy chain (MHC) IIA (∼50 ± 9 %), followed by IIX (32 ± 10 %) and MHC I (18 ± 5 %), with no difference between groups. Citrate synthase (mean: 87 ± 48), 3-hydroxyacetyl co A dehydrogenase (47 ± 17), lactate dehydrogenase (1567 ± 654), phosphorylase (162 ± 94), phosphofructokinase (250 ± 123) and creatine kinase (12,455 ± 6372) activities (in μmol/min/g prot) were not different between groups. Similarly, superoxide dismutase (7.9 ± 7 U/mg prot), catalase (8.8 ± 5.8 mmol/min/g prot), and overall antioxidant capacity (ORAC: 23055 ± 18,460 μmol/g prot) were not different between groups. Glycogen content was reduced in both chased groups and not replenished by day 3. Glycogen supercompensation was observed on day 16 in both chased groups (∼33 % higher than resting control group). The results confirm that blesbok have high muscle metabolic capacities, and that glycogen resynthesis is slow, which could lead to metabolite deficiency during prolonged chase events (>15 min).
Whole genome characterization of Listeria welshimeri isolates recovered from cattle abattoirs and retailers in Gauteng province in South Africa
Gana, James; Pierneef, Rian Ewald; Gcebe, Nomakorinte; Moerane, Rebone; Adesiyun, Abiodun Adewale (Springer, 2025-06)
The study used whole-genome sequencing (WGS) to characterize 12 isolates of L. welshimeri recovered from the beef production chain in Gauteng province, South Africa. Two sequence types (STs) were identified, with ST3294 accounting for 75% (9/12) and ST1084 for 16.7% (2/12) of the isolates. Antimicrobial resistance (AMR) plasmids detected included conjugative plasmid (MOBP2; T_virB11; virb4) in 58.3% and AMR plasmid (NFO33156) in 41.7% of the isolates. Two AMR genes, fosX (25%) and vga (G) (100%), along with 11 virulence factors, were present in all 12 isolates of L. welshimeri. The phylogenomic tree of L. welshimeri clustering based on the ST according to the source, type, and class of beef and beef products revealed three groups: ST3294 (n = 9), ST1084 (n = 2), and unassigned ST (n = 1). The findings of this study demonstrate the potential for transferring genetic materials from non-pathogenic L. welshimeri to pathogenic L. monocytogenes within the same ecological niche.
Wildlife substitution equivalents based on metabolisable energy for calculating stocking densities on Southern African wildlife ranches
Shepstone, C.A.; Van Rooyen, N.; Van Rooyen, M.W.; Bothma, J. du.P.; Burroughs, Richard E.J. (South African Society for Animal Science, 2025-07-23)
This study aims to bridge the gap between the large stock unit method and the grazer and browser unit methods for estimating the stocking densities of wild herbivore ungulates on wildliferanches and reserves using both extensive and intensive production methods. Animal substitution equivalents based on metabolisable energy are calculated to estimate stocking densities; however a n annual up-to -date vegetation evaluation is required to estimate the carrying capacity of the habitat to support wild herbivore ungulates without it being degraded over time. This study provides an applied approach to how refined large stock, wild herbivore, grazer, and browser u nit equivalents can be usedeffectively. The two production methods described differ in their intensity of animal management. In the extensive wild herbivore ungulate production method, the mean animal mass is used to calculate thelarge stock, wild herbivore, grazer, and browser substitution equivalent units, while in the intensive wild herbivore ungulate production method, the mean mass per physiological state, with varying percentages of suckling offspring, is used to do so. These methods are extrapolated from mean linear transformations of the different physiological states and sexes of the different types of herbivores. The extensive wild herbivore ungulate production method is preferred when evaluating wildlife ranches focused on hunting and tourism, as wildlife census data do not incorporate the numbers of males, females, and offspring, whereas the intensive wild herbivore ungulate production method is preferred for intensive breedingsystems in which the numbers of males, females, and offspring are known.
Characterization of domestic ruminant movement patterns in a transfrontier region of North-Eastern KwaZulu-Natal, South Africa
Ngoshe, Yusuf Bitrus; Gomez-Vazquez, Jose Pablo; Etter, Eric Marcel Charles; Thompson, P.N. (Peter N.) (Wiley, 2025-04)
INTRODUCTION : Livestock movement patterns play a crucial role in animal and public health management, disease transmission and sustainable livestock farming. Understanding these patterns is vital for disease surveillance and preventing the spread of animal diseases. STUDY AREA : This study was conducted in the far north-eastern region of KwaZulu-Natal (KZN) province, South Africa, with Eswatini bordering to the west and Mozambique to the north. The study area is located at a wildlife–livestock interface and includes sections classified as a foot-and-mouth disease (FMD) control zone. Animal and animal product movements within, into and out of the area are restricted by state veterinary-issued movement permits. AIMS : The study aimed to quantitatively describe livestock movement characteristics within, into and out of the study area and identify potential hubs for disease transmission. STUDY DESIGN AND SAMLING STRATEGY : Data sources included official animal movement permit records (2015–2018) from the KZN Department of Agriculture and Rural Development, and the data are obtained via face-to-face interviews with livestock traders (August to November 2020). Traders’ data were used to complement the interpretation of the permit dataset and to understand the livestock movement patterns, especially from the perspective of traders who operate from our study area. The permit data offered a detailed record of official livestock movements over multiple years, enabling us to identify the movement trends. In contrast, the face-to-face interviews provided real-time insights from traders regarding informal movement trends and disruptions not reflected in the permit data. The permit dataset was used to construct stratified animal movement networks by species using social network analysis (SNA), treating dip tanks (origins) and the destination locations (municipalities, districts or provinces) as two disjoint sets before being projected into a one-mode network. Bipartite-specific statistics were computed to compare the constructed networks. RESULTS : A total of 3598 movements between 2015 and 2018, representing 33,561 animals, were recorded from the permit datasets. Additional 74 movements representing 3296 animals occurred in the traders’ dataset in 2020. Of the total number of animals moved, 64% were directed outside the study area. Overall, the network analysis highlighted distinct movement patterns for cattle and goats, with Ndlondlweni and Phelandaba dip tanks as the key nodes facilitating animal movements. These are both dip tanks with high centrality and highly connected hubs, with the potential for facilitating the transmission of diseases to the entire province and other places. CONCLUSION : These findings contribute to a better understanding of livestock trade and animal movement dynamics for effective disease control and management. Two dip tanks emerged as high-frequency hubs for animal movements outside the study area, posing risks for disease transmission to the province and beyond. Intensifying surveillance in these areas is recommended to mitigate the spread of animal diseases. Veterinary authorities should enforce the use of animal movement permits by livestock traders for effective disease prevention and control.
Validation of a point-of-care serum progesterone cut-off for caesarean section timing in the bitch and its effect on neonatal outcomes
De Cramer, Kurt Guido Mireille; Joone, Carolynne Jane (Elsevier, 2025-12)
The aim of this study was to evaluate, in a clinical setting, the use of a serum progesterone concentration (PC) cut-off value of 4.6 nmol/L, measured on a point-of-care assay, as an indicator for performing safe preparturient caesarean section (CS) in the bitch. Privately-owned bitches, carrying at least two foetuses, were admitted for prepartum management. A parturient CS was performed once cervical dilatation was observed on vaginoscopy, with vaginoscopies performed at 08h00, 12h00 and 17h00 each day. A preparturient CS was performed when PC was ≤4.6 nmol/L, with PC measured in bitches with a closed cervix at the 17h00 examination. A total of 293 preparturient and 92 parturient CS were performed, with 2102 and 723 puppies delivered, respectively. There was no difference between preparturient and parturient CS in terms of the proportion of stillbirths (p = 0.91) or puppies surviving to 2 h post-delivery (p=1.00). Among live puppies delivered via preparturient CS, 99.5% (1986/1996) had normal viability (Apgar score ≥7 out of 10), compared to 98.0% (680/694) in the parturient CS group (p<0.001). The use of vaginoscopy in prepartum bitches is essential to avoid delaying surgical intervention in those bitches that enter Stage I of labour prior to PC dropping to ≤4.6 nmol/L. A PC of ≤6.4 nmol/l (2 ng/ml) is traditionally considered to indicate the expectance of onset of parturition within the next day (24 h), and is widely used as a cut-off for planned CS, however practitioners should be aware of rare instances of PC hovering between 6.4 nmol/L and 5.0 nmol/l up to 100 h before the onset of spontaneous parturition when using a point-of-care assay. Further research to establish safe cut-off values for CS using other progesterone assay systems, and in a wider variety of breeds, is warranted. HIGHLIGHTS • Preparturient caesarean section in the bitch can be performed safely. • With IDEXX Catalyst, serum progesterone concentration (PC) should be ≤ 4.6 nmol/L. • Vaginoscopy needed to identify bitches that enter Stage I of labour before PC drops. • A cut-off of 4.6 nmol/L may not be appropriate for other progesterone assays.
Shape and variability of the normal medial coronoid process by computed tomography in young adult labrador retrievers
Van der Laan, Luzanne; Kirberger, Robert M.; Fosgate, Geoffrey Theodore; Le Roux, Christelle (Wiley, 2025-11)
Medial coronoid process disease (MCPD) is the most frequently observed cause of elbow dysplasia, resulting in lameness in young, fast‐growing large‐breed dogs, including Labrador Retrievers (LRs). Computed tomography (CT) is the diagnostic imaging modality of choice for evaluating the medial coronoid process (MCP), as it is noninvasive and eliminates superimposition of the process by the radial head. This retrospective descriptive study aimed to describe the shape of the normal MCP on CT, to assess its variability within the LR breed, and to determine the normal Hounsfield units (HUs) of the MCP, medial radial head (MRH), and lateral radial head (LRH). Normal elbow CT studies of 51 South African guide dog LRs were reviewed. Using a repeatable imaging alignment technique, three principal MCP shapes were identified: ovoid, triangular, and softly pointed and were found to be dependent on the level of assessment. Males had significantly lower mean MCP HU compared to females. The mean HU of the MRH was consistently higher than the LRH and was also greater in attenuation on subjective assessment. Measuring MCP and radial head HU too proximally was suboptimal, as volume averaging was frequently encountered. The results of this study showed that although different alignment techniques may result in HU variations, they will not affect the HU to such an extent that the MCP would be misclassified as abnormal.
Seroprevalence of canid alphaherpesvirus-1 and associated risk factors in domestic dogs in North Queensland, Australia
Joone, C.J.; Gummow, Bruce; Horwood, P.F. (Elsevier, 2024-10)
Canid alphaherpesvirus-1 (CaHV-1) may cause a highly fatal haemorrhagic disease in neonatal pups and is associated with reproductive, respiratory and ocular disease in older dogs. Although assumed to have a worldwide distribution, there have been few reports of CaHV-1 in Australia. The aim of this study was to investigate the seroprevalence of CaHV-1 in household dogs in a residential suburb in Townsville, as well as in dogs attending two dog shows in the region. Study participants were recruited through door-to-door non-probability sampling (Douglas dogs, n = 185) or invited to participate (Show dogs; n = 76). Dog owners completed a questionnaire that investigated possible risk factors for recent exposure to CaHV-1. A serum sample from each dog was assayed for anti-CaHV-1 antibodies using a commercially available ELISA. Associations between seropositive dogs and owner-reported risk factors were analysed using univariable analysis and multivariable logistic regression models. The seroprevalence of CaHV-1 was 11.4 % (95 % CI 6.8–15.9 %) and 17.1 % (95 % CI 5.5–28.8) for the Douglas and Show dogs, respectively, with a pooled seroprevalence of 13 % (95 % CI 8.3–17.7 %). Dogs that had suffered from conjunctivitis within the previous 3 months or were involved in breeding were more likely to be seropositive to CaHV-1. No other significant risk factors were identified. In conclusion, CaHV-1 is circulating in dogs in North Queensland and may be contributing to foetal and neonatal losses in this region.

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