Maart / March 2026 The Monthly Magazine of the SOUTH AFRICAN VETERINARY ASSOCIATION Die Maandblad van die SUID-AFRIKAANSE VETERINÊRE VERENIGING Nutritional disorders of backyard poultry CPD THEME Biodiversity nuus•news Access to CPD Articles: https://www.sava.co.za/vetnews-2026/ VET
• Eastern Cape and Karoo Branch of the SAVA Congress: 15 & 16 May • KwaZulu-Natal Branch of the SAVA Congress: 30 & 31 May • Western Cape Branch of the SAVA Congress: 31 July & 01 August Dagboek • Diary June 2026 July 2026 August 2026 13th Int Crustacean Society Mid-Year Meeting 01-04 June Venue: STIAS – Stellenbosch Info: https://tcs2026.com/ NVCG Bush Break 06-07 June Venue: Skukuza, Kruger National Park Info: Vetlink: https://vetlink.co.za/nvcg-bush-break-2026/ RuVASA Congress 2026 08 - 10 June Venue: Champagne Sports Resort, Drakensberg, KZN Info: https://vetlink.co.za/ruvasa-congress-2026/ 56th Annual SASAS Congress 07 - 09 July Venue: Lagoon Beach Hotel, Cape Town Info: https://www.sasascongress.co.za/ SAVA Eastern Free State Congress 10-11 July Venue: TBC, Clarens Info: conference@savetcon.co.za Integrative Veterinary Medicine Conference 31 July - 02 August Venue: Protea Hotel, Stellenbosch Info: conference@savetcon.co.za Hill’s Nurses Hybrid Weekend 01-02 August Venue: TBC, Gauteng Info: corne@savetcon.co.za 23rd Annual SASVEPM Congress 19 - 21 August Venue: Sun City Resort, Rustenburg, North West Info: https://sasvepm.org/23rd-annual-sasvepm-congress/ 54th Annual PARSA Conference 31 August – 02 September Venue: Klein-Kariba, Bela-Bela Info: corne@savetcon.co.za Ongoing / Online 2026 March 2026 April 2026 May 2026 SAVETCON: Webinars Info: Corné Engelbrecht, SAVETCON, 071 587 2950, corne@savetcon.co.za / https://app.livestorm.co/svtsos SAVA Johannesburg Branch CPD Events Monthly - please visit the website for more info. Venue: Johannesburg Country Club Info: Vetlink - https://savaevents.co.za/ CPD Course: Introduction to Animal Welfare Science Online - self paced. Info: https://scientificveterinaryconsulting.com/courses/ animal-welfare-online-short-course/ CPD Course: Animal Research Ethics Online - self paced. Info: https://scientificveterinaryconsulting.com/courses/ essence-of-the-sans-10386-2021-online-short-course/ Wildlife Group of the SAVA Congress 2026 12 - 14 March Venue: 26° South Hotel , Muldersdrift, Gauteng Info: https://vetlink.co.za/wildlife-group-2026/ NVCG: The Veterinary Masterclass: Neurology 17 - 18 March Venue: Protea Hotel Stellenbosch (Techno Park) 19 - 20 March Venue: Johannesburg, Midrand Premier Hotel Vetlink: https://vetlink.co.za/nvcg-roadshow-march/ or +27 12 346 1590 SAVA Oranje Vaal Congress 17 - 18 April Venue: Khaya Ibhubezi, Parys Info: conference@savetcon.co.za UP: Beyond Basics: Mastering the Cardio-respiratory Patient: A Structured Clinical Approach 11 - 12 May Venue: Premier Hotel, Midrand, Gauteng Info: https://vetlink.co.za/beyond-basics/ INFO: www.vetlink.co.za
Vetnuus | March 2026 1 Contents I Inhoud President: Dr Ziyanda Qwalela president@sava.co.za Interim General Manager: Ms Sonja Ludik sonja@sava.co.za/ +27 (0)12 346 1150 Editor VetNews: Ms Andriette van der Merwe vetnews@sava.co.za Accounts / Bookkeeping: Ms Shaye Hughes accounts@sava.co.za/+27 (0)12 346 1150 Reception: Ms Hanlie Swart reception@sava.co.za/ +27 (0)12 346 1150 Marketing & Communications: Ms Sonja van Rooyen marketing@sava.co.za/ +27 (0)12 346 1150 Membership Enquiries: Ms Debbie Breeze debbie@sava.co.za/ +27 (0)12 346 1150 Vaccination Booklets: Ms Debbie Breeze debbie@sava.co.za/ +27 (0)12 346 1150 South African Veterinary Foundation: Ms Debbie Breeze savf@sava.co.za/ +27 (0)12 346 1150 Community Veterinary Clinics: Ms Claudia Cloete manager@savacvc.co.za/ +27 (0)63 110 7559 SAVETCON: Ms Corné Engelbrecht corne@savetcon.co.za/ +27 (0)71 587 2950 VetNuus is die amptelike publikasie van die Suid Afrikaanse Veterinêre Vereeniging (SAVV). Alle regte word voorbehou. Geen deel van hierdie publikasie mag aangehaal, gedupliseer, versprei of aan die publiek beskikbaar gestel word in enige vorm sonder die uitdruklike skriftelike toestemming van die SAVV nie.Hierdie publikasie is uitsluitelik bedoel vir veearts en veearts verwante professionele persone soos deur die Suid Afriaanse Veterinêre Raad erken word. Wyl alles moontlik gedoen word om om die akkuraatheid van die inhoud te verseker, aanvaar nie die redaksie, SAVV of enige van die personeel, lede, werknemers of agente enige regsaanspreeklikheid vir enige verlies, skade of bevooroordeeldheid, hetsy direk of indirek, wat mag spruit uit enige stelling, feit, opinie, advertensie of aanbeveling hierin gepubliseer. Enige advertensie of verwysing na n spesifieke produk is toevallig en word nie noodwending onderskryf of aanbeveel deur die SAVV nie. VetNews is the official publication of the South African Veterinary Association (SAVA). All rights are reserved. No part of this publication may be quoted, reproduced, distributed, or made publicly available in any form or by any means without the prior express written consent of SAVA. This publication is intended solely for veterinarians and paraveterinary professionals as recognised by the South African Veterinary Council. While every effort is made to ensure the accuracy of the content, neither the editorial board, SAVA, nor any of its office bearers, members, employees, or agents shall be held liable for any loss, damage, or prejudice, whether direct or consequential, arising from any statement, fact, opinion, advertisement, or recommendation published herein. The inclusion of advertising or reference to specific products or services does not imply endorsement by SAVA. STREET ADDRESS 47 Gemsbok Ave, Monument Park, Pretoria, 0181, South Africa POSTAL ADDRESS P O Box 25033, Monument Park Pretoria, 0105, South Africa TELEPHONE +27 (0)12 346 1150 FAX General: +27 (0) 86 683 1839 Accounts: +27 (0) 86 509 2015 WEB www.sava.co.za CHANGE OF ADDRESS Please notify the SAVA by email: debbie@sava.co.za or letter: SAVA, P O Box 25033, Monument Park, Pretoria, 0105, South Africa CLASSIFIED ADVERTISEMENTS (Text to a maximum of 80 words) Sonja van Rooyen assistant@sava.co.za +27 (0)12 346 1150 DISPLAY ADVERTISEMENTS Sonja van Rooyen assistant@sava.co.za +27 (0)12 346 1150 DESIGN AND LAYOUT Sonja van Rooyen PRINTED BY Business Print: +27 (0)12 843 7638 VET Diary / Dagboek II Dagboek • Diary Regulars / Gereeld 2 From the President 4 Editor’s notes / Redakteurs notas Articles / Artikels 10 Leveraging Small Biodiversity Reserves to Prevent Zoonotic Disease 16 Poisoning.... 20 Suspected Glyphosate Poisoning in a Dog 24 Zoonotic Tuberculosis... 32 Steve Wimberley : The Clicking Heart Association / Vereniging 34 SAVA Awards 37 SAVA News 41 In Memoriam Vet's Health / Gesondheid 42 Life Coaching Technical / Tegnies 44 Dental Column Marketplace / Markplein 45 Marketplace Jobs / Poste 46 Jobs / Poste 48 Classifieds / Snuffeladvertensies 16 20 Click on the image to access Vetnews CPD articles « nuus•news 44
Vetnews | Maart 2026 2 « BACK TO CONTENTS This edition of Vetnews focuses on three critically important and interconnected themes within the veterinary and environmental health space — biodiversity, animal poisoning, and tuberculosis (TB). These issues highlight the essential role veterinarians play in protecting ecosystem health, safeguarding animal welfare, and advancing public and environmental health within an increasingly complex and interconnected world. The veterinary profession remains central to the One Health approach, working at the interface between animals, people, and the environment. The past month marked an important milestone for the South African Veterinary Association (SAVA), as we convened our first strategic planning session to advance collaboration through Memoranda of agreement with our affiliate organisations. These discussions represent meaningful progress toward building a unified, sustainable, and responsive professional community. We also engaged constructively with the Executive of the South African Association of Animal Health Technicians (SAAHT), with encouraging progress made toward strengthening cooperation and alignment between veterinarians and para-veterinary professionals in support of accessible and effective veterinary services. The South African Veterinary Association extends its congratulations to the World Veterinary Association and the Japan Veterinary Medical Association as they prepare to host the 41st World Veterinary Association Congress in Tokyo, Japan, from 21–24 April 2026, under the theme “Veterinary Medicine for One Health”. The Congress remains a key global platform for advancing veterinary science, professional collaboration, and One Health leadership. SAVA wishes the organisers every success in delivering a successful and impactful Congress. We further thank V-Tech for their continued sponsorship and support in enabling participation in these important international engagements and strengthening SAVA’s marketing initiatives. We further extend our warmest congratulations to Dr Olatunji Nasir on his historic election as President-Elect of the World Veterinary Association (WVA). This marks a proud milestone for the global profession, as it is the first time the Association will have an African President-Elect. His election reflects the growing leadership and influence of African veterinarians internationally, and SAVA looks forward to working closely with Dr Nasir in advancing shared continental and global veterinary priorities. Foot-and-Mouth Disease (FMD) remains a priority animal health concern nationally, with continued efforts underway to stabilise and contain the outbreak. The government received additional vaccine supplies during the past month, with further vaccine orders anticipated over the coming weeks to sustain the national response. Provinces that had previously exhausted vaccine stocks have now resumed vaccination campaigns, largely implemented on a risk-based approach targeting high-risk areas and susceptible livestock populations. An important development is the inclusion of private veterinarians in the vaccination programme. Permission will be granted for private practitioners to undertake vaccinations in closer cooperation with State Veterinary Services, while State Veterinarians retain oversight to ensure appropriate implementation, traceability, and alignment with national disease control measures. These developments reinforce the importance of coordinated action between government, private veterinarians, industry, and livestock owners in achieving sustainable disease control. This month, we will once again recognise excellence within the profession during the Faculty Prize Giving Day, celebrating the academic achievement and dedication of veterinary professionals who nurture the future leadership of veterinary science in South Africa. Looking ahead, the Association enters an active governance period, with upcoming EXCO, FINCO, and FEDCO meetings, where strategic, financial, and organisational priorities will continue to be advanced in support of a resilient and member-focused SAVA. We are equally pleased to announce that the call for nominations for the SAVA Awards has been circulated. These awards provide an important opportunity to recognise excellence, leadership, and outstanding contributions within our profession, and members are encouraged to participate actively in acknowledging colleagues who continue to elevate veterinary science and service in South Africa. As we move forward, SAVA remains committed to strengthening professional unity, advancing scientific leadership, and ensuring that the veterinary profession continues to contribute meaningfully to biodiversity protection, animal health, and societal wellbeing. Together, the real work continues. v Groetnis! Ziyanda From the President Dear members, Vets at work, focusing on sustainable ecosystems
Vetnuus | March 2026 3 To find out more: You are looking for a be琀琀er way to exit from or sell your practice. You want to become a shareholder. www.companion.partners WhatsApp View Video Download Value Proposition co.mpanion is not a corporate body, it is a professional owned and led veterinary model that is right for you if: Building be琀 琀er practice together. co.llaborative model that gives you the ownership, support and autonomy Image: Dr Werner Odendaal, Shareholder & Team Member, To find out more: You are looking for a be琀琀er way to exit from or sell your practice. You want to become a shareholder. www.companion.partners WhatsApp View Video Download Value Proposition co.mpanion is not a corporate body, it is a professional owned and led veterinary model that is right for you if: Building be琀 琀er practice together. co.llaborative model that gives you the ownership, support and autonomy Image: Dr Cailin Cunningham, Shareholder & Team Member,
Vetnews | Maart 2026 4 « BACK TO CONTENTS As we bid farewell to the month of love, we also hopefully bid farewell to the heat of summer. In many places, the colours of autumn are already showing in preparation for the big leaf drop. I hope that it rained where it was so bitterly dry. In the first week of March, we are celebrating World Wildlife Day with a bit of a peculiar topic: “Medicinal and Aromatic plants”. The complete theme is: “Medicinal and Aromatic plants Conserving Health, Heritage and Livelihood “, but how do you even connect that to wildlife and veterinarians in particular? I found an article on Biodiversity and pathogens. A very interesting piece of research to show how the two fit into each other. How well do you know your Medicinal plants? Most veterinarians can identify poisonous plants when animals get sick, but do we know what plants are beneficial to our clients? An estimated 60,000 plant species are used globally for medicinal and related purposes. Our world heals through plants. Just look at the cycle of an overgrazed piece of land. How, by different species, the plants protect and heal the soil. Dr Willem Schultheiss presented a talk that I attended on farming micro-organisms. Micro-organisms are the building blocks for healthy plants, and healthy plants are the building blocks for healthy consumers, including our animals, whether raw (on the hoof) or processed. May we delve a little into the healthy plants we can offer our clients? On that topic, another issue is touched on, and that is Poisoning. Whether plant origin or otherwise. Lookout for the article on the perceptions of recreational drug users and the discrimination feared at the veterinary practice after a pet may or may not have ingested such drugs. The Lincoln Institute Veterinary Resiliency program is winding down, and I followed it on the side. The feedback has been fenomenal and I wish every veterinarian over the entire practice scope could have done it. I hope that the people who completed the program will be the yeast to ‘infect’ others with good practice, great resiliency, better relationships and the best self-care there is. Talking of which, the article by Dr Matts Abadsidis expertly drives that point home in his piece on “The Balance that is Illusive”, taking it from being elusive to making it practical for each day. It starts with drinking a glass of water every morning. Now, how difficult can that be? See the article for a host of ideas on how to balance work and private life and how to implement self-care. We mourn the untimely passing of two veterinarians: Dr Estian van As and Dr JW Eksteen. Our sincere condolences to the families. I hope that this month treats you well. If you celebrate World Wildlife Day in a special manner, please send some photos to us at Vetnews. We would love to see what you do. Andriette v From the Editor Editor’s notes / Redakteurs notas
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Vetnews | Maart 2026 6 « BACK TO CONTENTS
Vetnuus | March 2026 7 “The South African Veterinary Association aims to serve its members and to further the status and image of the veterinarian. We are committed to upholding the highest professional and scientific standards by utilising the professional knowledge, skill and resources of our members, to foster close ties with the community and thus promote the health and welfare of animals and mankind”. MISSION STATEMENT Servicing and enhancing the veterinary community since 1920! Tel: 012 346 1150 E-mail: vethouse@sava.co.za www.sava.co.za STUDY VETERINARY MEDICINE IN CYPRUS DOCTOR OF VETERINARY MEDICINE (DVM) 5-Year Programme for High School Leavers unic.ac.cy/vet EARLY CLINICAL EXPOSURE AND TRAINING in small groups with both large and small animals from year one. CURRICULUM ALIGNED WITH RCVS, AVMA, EAEVE, AND WORLD ORGANIZATION FOR ANIMAL HEALTH INNOVATIVE, HANDS-ON CURRICULUM designed to offer you the necessary Day One skills required to follow any career pathway in veterinary medicine. COMMUNITY SERVICE AND ANIMAL WELFARE volunteerism and service opportunities with sheltered animals. TALENTED AND DEDICATED FACULTY MEMBERS AND STAFF facilitating and guiding your learning and development as a veterinarian. FINANCIAL AID SCHOLARSHIPS AVAILABLE
Vetnews | Maart 2026 8 « BACK TO CONTENTS Order SAVA name badges for your practice! Available in gold or silver Price: R165 per badge (VAT inclusive, excludes packaging & courier fee) For more information or orders contact Sonja van Rooyen at SAVA: Tel: 012 346 1150 E-mail: assistant@sava.co.za Introduction to Animal Welfare Science 2 CPD POINTS • 1 HOUR • SELF-PACED ONLINE MODULE With a extended conversation between Dr Bert Mohr (Veterinary Specialist, PhD) and Dr Bevin Meyer (Veterinarian, MSc) SAVC ACCREDITED CPD A look at how animals’ ability to feel shapes our responsibility to promote their wellbeing — and explores evolving societal perceptions of animal welfare and consciousness. SVC_Ad_90x120.indd 1 2025/11/28 12:11 Animal Research Ethics Online Short Course 8 CPD POINTS • 8 HOURS • SELF-PACED ONLINE COURSE Presented by bit.ly/SANS10386 Work with animals in science? This course distils the essentials of SANS 10386:2021, guiding veterinarians and para-veterinary professionals with the core principles for ethical, compliant animal care and use in South Africa. SAVC ACCREDITED CPD SACNASP ACCREDITED CPD DR BERT MOHR VETERINARY SPECIALIST, PHD
Vetnuus | March 2026 9 Registration Type Early-bird Standard Member Full Programme: Inperson/Online R4,900.00 R5,450.00 Non Member Full Programme: Inperson/Online R6,500.00 R7,050.00 Pensioners (retired | not active) Full Programme: Inperson/Online R2,400.00 R2,950.00 Post-Graduate Students Full Programme : Inperson/Online R3,200.00 R3,750.00 Pre-Graduate Students Full Programme: Inperson/Online R2,000.00 R2,550.00 International Full Programme : Inperson/Online R7,700.00 R8,250.00 Member 2 Day Registration: Inperson Only R4,300.00 R4,850.00 Non Member 2 Day Registration: Inperson Only R5,700.00 R6,250.00 Member 1 Day Registration: Inperson Only R2,100.00 R2,650.00 Non Member 1 Day Registration: Inperson Only R3,700.00 R4,250.00 https://vetlink.co.za/wildlife-group-2026/ https://vetlink.co.za/wildlife-group-2026/ 12-14 March 2026 WILDLIFE GROUP OF THE SAVA CONGRESS 2026 Theme: FMD et al. Risks to Wildlife Have You Registered Yet ? Early-bird Rates 05 February 2026 Programme available on the website.
Vetnews | Maart 2026 10 « BACK TO CONTENTS Abstract: In today’s landscape of zoonotic pathogen outbreaks, the dilution effect theory, i.e., the theory that greater biodiversity can help curb pathogen transmission among wildlife, has gained significant attention. However, the positive link between animal diversity and pathogen richness urges us to apply this concept with caution. It is crucial to explore how conservation biology can safeguard human health by preventing the emergence of zoonotic diseases. By investigating the implications of conservation strategies on animal communities and pathogen transmission as well as the adaptive capabilities of pathogens, we propose that biodiversity conservation based on small reserves can effectively reduce pathogen spread in wildlife, provided certain measurable conditions are met. Given the urgent need to tackle both zoonosis disease emergence and biodiversity loss, these interventions should be prioritised and implemented without delay. Introduction The urgency to reverse the loss of biodiversity [1] has increased societal interest in environmental conservation, pushing it onto political agendas. However, many decision-makers remain hesitant to implement sustainable conservation programs [2]. The COVID-19 pandemic, driven by SARS-CoV-2, has highlighted the global threat of zoonotic diseases, which jump from animals to humans, causing significant health, social, and economic disruptions. No longer just a topic for debate, the emergence of zoonoses is now clearly linked to humaninduced changes in our natural environments [3]. While geopolitical factors and financial resources often dominate discussions on international policies, short-term economic costs tend to overshadow the long-term impacts of these decisions. A key barrier is the lack of demonstrated synergies among crises that would maximise investment. To tackle this, we need a comprehensive cost-effectiveness analysis of how different habitat conservation strategies can mitigate disease emergence, encouraging authorities to engage more actively. Since the groundbreaking research by Ostfeld and Keesing (2000), numerous studies have highlighted the potential prophylactic effects of biodiversity conservation on infectious disease transmission [4]. This is evidenced by a frequent negative correlation between species richness and pathogen transmission [5–7]. However, the so-called ‘dilution effect’ is often non-linear and predicting the impact of biodiversity protection on zoonosis emergence in humans remains complex [8]. Thus, leveraging conservation biology tools to reduce the risk of emerging infectious diseases [9] demands a deeper understanding of how the dilution effect applies across various ecosystems [10–12] and processes, such as those involved in biodiversity loss [13]. Most studies focus on transmission dynamics within ecosystems, particularly whether altered pathogens are zoonotic [13,14]. However, pathogen circulation among animals is just the initial step toward spillover, overlooking critical animal-human interactions that biodiversity protection could influence. To safeguard human health, we must examine both the biological and sociological links between biodiversity loss and human exposure to zoonotic diseases, including direct human-animal interactions. Recent studies linking conservation strategies and infectious diseases highlight a significant dependence on local contexts and the specific pathogens involved [15]. It is important to point out here that we use the term “pathogen” to represent any kind of parasitic microbe. Obviously, the host spectrum and its adaptive potential (which are key components for a potential dilution effect) will be extremely different according to the kind of microbes considered (e.g., viruses, bacteria, helminths, etc.). This variability of contexts and community assemblages complicates efforts to identify universally applicable win-win solutions for environmental protection and public health. Unlike research on the dilution effect, these studies often prioritise human disease burden [16]. Since human disease burden depends on pathogen circulation, socio-economic factors, and pathogen adaptation (whether partial or complete), this perspective falls short in explaining how biodiversity conservation reduces spillover risks [17]. While the general applicability of the dilution effect has garnered considerable support [6,8,12,13,18], it is evident that policies rooted in this effect cannot be universally applied across all diseases and contexts. Leveraging Small Biodiversity Reserves to Prevent Zoonotic Disease: Insights from Dilution Effect and Pathogen Adaptation Theories Audrey Arnal, Rodolphe Elie Gozlan, Nathalie Charbonnel, Marie Bouilloud, Andrea Chaves, Manon Lounnas, Michel Gauthier-Clerc , Ana L. Vigueras-Galván, Céline Arnathau, David Roiz, Ana I. Bento, Serge Morand, Chris Walzer, Gerardo Suzán, Rosa Elena Sarmiento Silva, and Benjamin Roche
Vetnuus | March 2026 11 Leading Article A deeper mechanistic understanding is essential. Additionally, pathogens play a pivotal role in maintaining both vertebrate and invertebrate biodiversity—aligning with the Janzen-Connell hypothesis [19,20], which underscores the need for a multipathogen approach to this issue. In this light, it becomes crucial to identify the specific conditions and settings where broadscale policies can effectively impact local ecosystems. This study explores how conservation biology can reduce pathogen transmission among wildlife, ultimately lowering spillover risks to humans. Instead of focusing on direct human transmission, which is influenced by socio-economic and behavioural factors beyond this study, we concentrate on enzootic pathogen circulation, the early stage of potential epidemics. Our investigation examines global conservation strategies and their impact on wildlife pathogen transmission, pinpointing critical knowledge gaps for designing strategies with dual benefits for biodiversity and public health. By assessing the risks and rewards of each approach, we identify strategies that offer the safest public health co-benefits while minimising zoonotic risk. Potential Impacts of Landscape Conservation Strategies on Pathogen Transmission — The Role of Pathogen Adaptation and Habitat Connectivity Since early research on the dilution effect [21,22], using conservation biology to reduce the risk of emerging infections has been considered. However, our understanding of the dilution effect, its mechanisms, and applicability was then underdeveloped. Since then, knowledge in conservation biology has significantly grown, highlighting the need to merge these fields. Many reviews have outlined the conditions under which a dilution effect can be observed—such as significant variability in host competence, horizontal transmission, a link between host abundance and competence, and frequency-dependent transmission. Similarly, conservation strategies have been extensively explored, from identifying key species to target, determining the optimal size of protected areas, and ensuring connectivity between habitat patches [23]. Rather than delving into an exhaustive review of this literature here, more detailed discussions are available in the supplementary materials. What remains clear is the pressing need to align these advances in conservation and disease ecology, paving the way for strategies that not only protect biodiversity but also mitigate the risk of pathogen spread. In this study, we focus on the potential effects of concrete conservation strategies on host communities and, consequently, the expected circulation of pathogens within ecosystems (results are summarised in Table 1). To do so, we consider the balance between hazard (pathogen diversity, defined by the number of pathogen species, as a potential source of harm) and risk (actual exposure to a given pathogen through circulation), as described by Hosseini et al. (2017) [24]. Our focus is specifically on landscape selection strategies, particularly the debate over whether a single large reserve or several small reserves (i.e., the SLOSS debate) is more effective. It is important to note that we centre our analysis on pathogens with minimal virulence in their wild hosts. We define here “virulence” as the infection cost for the host, for which a “minimal virulence” has a negligible impact on host abundance. As such, they do not significantly disrupt host community diversity or assembly — to avoid introducing complex host-pathogen dynamics. Additionally, we have chosen to maintain a broad perspective rather than focusing on a single pathogen to keep our findings widely applicable (for specific examples of how conservation strategies affect pathogen transmission, see Lambert et al., 2020) [25]. Conservation Strategies Consequences on Animal Communities Ref Consequences on Pathogens Communities on the Ecosystem A Consequences on Pathogens Communities on the Ecosystem B Several Small Reserves Maximize regional diversity by combining small patches with several different species. Many patches, interconnected,with low species richness in each [26,27] Rapid pathogen adaptation: high pathogen transmission within each reserve, which may lead to different pathogen adaptation within each patch (local speciation). Slow pathogen adaptation: hot and cold spots of transmission and adaptation. Strong genetic drift effects may limit adaptation if interconnectivity between patches is strong. Intermediate Strategy Maximize the time to population extinction Few patches with a reasonably high species richness 28,29] Medium level of transmission. Determining the ideal patch size could be considered by looking at the pathogen communities. Single Large Reserves Larger areas contain more species than smaller areas (species-area relationship theory and equilibrium theory of island biogeography). This decreases the probability of species extinction. Classic Reserves One patch with high species richness [30,31] More pathogens but less transmission (dilution effect) More pathogens species and more transmission (amplification effect) Biodiversity Hotspots One patch with high species richness [32,33] More pathogens but less transmission (dilution effect) More pathogens species and more transmission (amplification effect) Key Biodiversity Areas (KBAs) Case-by-case [34,35] Host communities being heterogeneous between KBAs, it is difficult to extrapolate for pathogen communities Table 1. Summary of different conservation strategies, their impact on animal communities, and their potential impact on pathogen transmission. We assume the conditions necessary for a dilution effect: (1) horizontally transmitted pathogen (i.e., no vertical transmission), and (2) animal communities with a high probability of extinction for low-abundance species. As shown in Figure 1, ecosystem A assumes a perfect positive correlation between competence and species abundance (a perfect context for a dilution effect). Conversely, in ecosystem B, we assume a perfect negative correlation between competence and species abundance (a perfect context for an amplification effect). >>>12
Vetnews | Maart 2026 12 « BACK TO CONTENTS In a landscape-scale conservation strategy using multiple small reserves, two critical factors come into play: the adaptive capacity of pathogens and the connectivity between patches [36,37]. It is worth pointing out that pathogen adaptation is always challenging to forecast and can take many different forms. Nevertheless, the likelihood of pathogen adaptation (i.e., increased transmission in this case) is linked to its adaptation potential, which is the quantity that could be directly measured (e.g., pathogen mutation rate, pathogen substitution rate, etc.). When inter-patch connectivity is low, patch sizes are reasonable, and pathogens adapt quickly to their environment, this approach can foster local pathogens’ adaptation. In other words, each patch would host its own strain (i.e., a genotype), leading to low pathogen diversity at the patch level but high diversity across the entire region. Pathogen transmission would likely be high within individual patches, but low between them [38,39]. While the pathogen hazard remains high due to its wide geographical distribution, the risk of widespread transmission would be more contained. On the other hand, if a pathogen adapts more slowly to its environment, we would expect a mosaic of ‘hot’ and ‘cold’ spots of adaptation [40]. In hotspots—where pathogens are well adapted— transmission would be high. But in cold spots, where environmental changes outpace pathogen adaptation, transmission would be low, possibly even leading to local pathogen extinction. Compared to fast-adapting pathogens, this scenario would see a decrease in overall transmission and pathogen diversity at the landscape level. As a result, both the hazard and the risk of the remaining pathogens would likely be lower. These impacts can be significantly influenced by increasing patch connectivity. When patches are fully connected, the dynamics resemble those of a single large population, where high pathogen adaptation and transmission are favoured—though predicting exact outcomes becomes more challenging (see Table 1). On the other hand, with low or intermediate connectivity, pathogens may struggle to adapt due to conflicting pressures between local and regional environments [38]. This tension limits a pathogen’s ability to thrive in both contexts, potentially resulting in a global reduction in both hazard and risk. However, if connectivity becomes too strong, it can create a complex mosaic of adaptive responses, especially under high genetic drift, making patterns of pathogen adaptation difficult to predict. To leverage this type of conservation strategy for reducing pathogen transmission, it is essential to strike the right balance— determining the ideal patch size and connectivity level to maintain this local-regional adaptation conflict. Doing so could help minimise transmission levels [22] and offer a clear benefit in terms of the hazard-risk trade-off. Such a threshold, when identified, can become a key tool to develop win-win strategies between biodiversity protection and human health. This approach contrasts with the design of traditional large reserves, which are often based on specific conservation needs, such as protecting biodiversity hotspots or preventing areasensitive species loss. While large reserves may offer ecological benefits, they often result in high species and pathogen richness, making their impact on pathogen circulation harder to predict. These areas might target Key Biodiversity Areas (KBAs), but due to the diversity of host communities within and between KBAs, the effects on pathogen dynamics remain uncertain. Some conservation strategies focus on specific species, like keystone species, to maintain high species richness. In these cases, the outcome for pathogen transmission depends heavily on the makeup of surrounding animal communities— particularly the ratio of competent versus non-competent species in the ecosystem. Similarly, focusing on flagship species may boost conservation efforts but have little impact on pathogen dynamics unless that species plays a pivotal ecological role. Translocation strategies are also unlikely to affect pathogen transmission unless they significantly alter the structure of animal communities. In summary, developing large reserves to mitigate zoonotic risks may produce highly variable results, making it a less reliable option for protecting human health from zoonoses. Figure 1. Examples of dilution and amplification effect. The competence (number of circles) and abundance (number of individuals per species) within animal communities, and their influence on pathogen transmission. Both ecosystems show a perfect positive (Ecosystem A), null (Ecosystem B) and negative (Ecosystem C) correlation between competence and abundance of each species (species 1 to 9). A dilution effect is expected in Ecosystem A, an amplification effect in Ecosystem C, while no impact on pathogen transmission is expected in Ecosystem B. Leading Article Leveraging Small Biodiversity Reserves to Prevent..... <<< 11
Vetnuus | March 2026 13 Discussion and Perspectives In this analysis, we explored the potential impact of conservation strategies on the enzootic circulation of pathogens, which is the critical first step before pathogens spillover into human populations. We highlighted that conservation strategies can have a broad range of effects on pathogen transmission—some positive, some negative. Notably, while some of these impacts may be anticipated, others remain unpredictable, raising concerns about the safety of their implementation. From our current understanding, establishing several small reserves with moderate interconnection between patches seems to offer the most reliable outcome. This approach hinges on the adaptive capacity of pathogens, a factor that can be measured, making it a more manageable strategy. Today, our knowledge is not sufficient to model quantitatively and provide a forecast on the impact of conservation biology on the reduction of pathogen circulation. Therefore, it’s essential to quantify both host species’ competence, their evolution and patch connectivity to fine-tune the optimal reserve size, striking a balance between species richness and low pathogen transmission. Conceptually, a win-win scenario appears achievable with this strategy of several small reserves. Our findings present a more optimistic perspective compared to earlier work, yet align with studies suggesting that the dilution effect often arises in the context of biodiversity loss [13]. The difference likely stems from the metrics we employed. Our focus was on enzootic circulation of pathogens, whereas the link between enzootic transmission, human exposure, and subsequent human-to-human spread involves distinct processes that require separate, careful consideration. While our study addresses a crucial gap by assessing how specific conservation strategies may affect pathogen transmission within animal communities, it does not provide direct recommendations for public health policy. However, we believe that fully understanding the mechanisms at play in each stage of pathogen transmission—from wildlife to humans—will be key to developing successful, win-win strategies that benefit both biodiversity and human health. Indeed, the success of conservation approaches in supporting public health hinges on carefully balancing the risks, benefits, and hazards they introduce [24]. Achieving an ecosystem with high biodiversity, which also implies greater pathogen diversity, but low pathogen transmission—the ultimate goal—requires a delicate balance. While this approach reduces risk (by preventing pathogen amplification), it increases hazard (more pathogens within the ecosystem [24]). Managing these hazards effectively calls for a better characterisation of the interface between enzootic circulation and human exposure. It is also important to recognise potential tensions between the most ecologically beneficial conservation strategies and those aimed at reducing pathogen transmission. Identifying and navigating these trade-offs is essential to designing sustainable, locally tailored solutions that engage all stakeholders. Conservation strategies are not solely about maximising species richness; they may prioritise preserving genetic diversity or species’ evolutionary potential [41]. In addition, social or ethical objectives often influence these strategies, such as reintroducing iconic species or eradicating invasive ones [42]. Socio-economic factors, like indigenous land rights or sustainable food production, also play a crucial role [43]. Reducing pathogen transmission is not without trade-offs either, as pathogens play a crucial role in shaping biodiversity [44] and habitat quality [45]. Therefore, efforts to limit pathogens should focus on those with zoonotic potential. Meanwhile, certain conservation strategies, like managing habitat matrices or establishing ecological corridors, are too context-dependent to predict their broader impact on pathogen transmission accurately. Strategies aimed at promoting the dilution effect or mitigating pathogen amplification could offer pathways to reducing pathogen transmission. Targeting species that contribute to dilution could help manage zoonotic outbreaks [46]. Ecological traits also matter: fast-living species, which often serve as disease reservoirs [47], tend to thrive in degraded landscapes, potentially increasing their number and elevating transmission risks. Developing surveillance systems in areas where human-wildlife interactions are frequent, like urban parks, could provide crucial insights into zoonotic pathogens transmission [18]. In conclusion, exploring ‘win-win-win’ strategies benefiting public health, biodiversity, and the economy is both feasible and essential. Mathematical models exist to test these ideas, and further research based on local data is needed to understand their effectiveness in diverse environments. While more data is required for safe application of large reserves, our study demonstrates the potential of conservation strategies based on small reserves to limit pathogen circulation and reduce human exposure safely. However, caution is necessary, as pathogen transmission effects can be complex. Now more than ever, integrating conservation with public health strategies is crucial. v References Ripple, W.J.; Wolf, C.; Newsome, T.M.; et al. World Scientists’Warning to Humanity: A Second Notice. 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