The word “stray” has different meanings to different people. For some people, a “stray” is an animal that is straying away from home – it has an owner but is lost or has escaped its home. For others, a “stray” animal is an unowned animal. At ICAM, we don’t presume to know the ownership status of “stray” animals. We equate the term “stray” with the term “free-roaming”, which is the term we usually use – this describes an animal roaming on public property without any obvious supervision from an owner. We recognise that this free-roaming animal may be an owned animal that is roaming, an owned animal that has been lost, an animal that is ‘community owned’ with more than one household offering care but no one that claims ownership, or an unowned animal – this can include ‘feral’ animals, which are unsocialised and live independently of people.

Humane Population Management is a compassionate, evidence-led approach to managing Dog (DPM) or Cat (CPM) populations to improve our neighbourhoods for everyone.  Population management is like fixing a leaky tap. Shelters are buckets catching water but eventually overflowing; culling is mopping endlessly while the tap continues to leak. Population Management finds the source of the leaks – the origins of unwanted stray dogs and cats – and uses a toolbox of solutions targeted to those sources. Sources include abandonment, loss of owned animals and failure to reunite with owners, owned animals roaming freely outside their home, and stray animals born on the streets. Solutions include sterilisation, vaccination, access to vet care, education, legislation, community engagement and governance. By addressing root causes, population management improves animal welfare and community well-being.

• Dogs and cats are ubiquitous in human communities – wherever there are people, there are dogs and cats – including in cities where over half the world’s population lives. Globally, 75% of dogs and 80% of cats are free-roaming. These stray dogs and cats face a number of challenges including malnutrition, disease and injury. They also present public health and safety risks including zoonotic diseases, bites and road traffic accidents. Together these challenges and risks can cause significant concern to citizens who may both fear dogs and cats and feel empathy for their suffering.
• The following provides a more detailed explanation of each area of problems experienced or caused by stray animals:
  • Animal welfare: Unmanaged dog and cat populations will include a high proportion of free-roaming and unowned animals that are receiving minimal or no care. This leads to animal welfare problems, including malnutrition and starvation (e.g. 23% of unowned dogs observed to be emaciated or thin in Bali; Hiby et al 2018), high levels of disease and injury that go untreated, discomfort from exposure to environmental extremes, and fear and distress from negative interactions with other animals and people. As a result of these challenges to their welfare, free-roaming dogs and cats have high levels of mortality, in particular when young (e.g. 75% kitten mortality in free-roaming cats Miller et al 2014, and 82% mortality of free-roaming dogs below 1 year of age in India, Pal 2001)
  • Public health: Unmanaged dog and cat populations present risks to public health and safety. Road traffic accidents and dog bites cause people injuries, distress and even fatalities, and lead to significant costs to health services. Zoonotic diseases threaten the health of animal and people. Rabies is the most fatal virus and leads to an estimated 59,000 human deaths per year (Hampson et al 2015) of which >95% are transmitted through the bite of an infected dog. Other zoonotic diseases are transmitted via infected faeces (e.g., echinococcosis from dog faeces and toxoplasmosis from cat faeces) or via vectors such as sand flies (e.g., leishmaniasis).
  • Public perception: People may fear dogs or cats or perceive them to be a nuisance; due to noise, faecal pollution and disturbing garbage. Alternatively, they may feel distressed by seeing dogs or cats suffer, in particular sick and dying puppies and kittens. Either perception may cause conflict within a community, lead people to avoid certain areas of their community or to aggressive interactions between people and animals. These concerns may also be reported to local authorities; dog-related and cat-related complaints, whether expressed as concern for animals or annoyance about them, can be a significant concern for officials.
  • Negative impacts on other species: Some locations will have local wildlife populations that are vulnerable to predation, stress or disease transmission from dogs or cats. Livestock may also be at risk of negative interactions with roaming dogs through predation, harassment or disease transmission, such as echinococcosis and rabies.

• For a full answer to this question, see ICAM’s post ‘Why not cull?’
• Culling of dog and cat populations has been repeatedly shown to be expensive, and ineffective at sustained population reduction. Dog and cat populations replenish quickly post-culling, leading to skewed demographics with a higher prevalence of young, unvaccinated animals that may exacerbate disease transmission. Culling often involves cruel practices, leading to suffering for animals and distress within communities, causing significant conflict between the public and authorities.

Culling is also known as ‘elimination’ and may be qualified by the terms ‘mass’ or ‘targeted’; however, there is no recognised threshold or criteria for when the culling of dogs or cats should be termed ‘mass’ culling.  Culling is the killing of animals for reasons other than their individual welfare state; this may be simply their location or type. For example, attempting to cull all the free-roaming dogs within a particular municipality, with the aim of reducing or eliminating the population. Or as a precaution against a perceived disease risk without assessment of the individual animal’s disease status. Authorities may also cull owned cats and dogs if their owners are not keeping the animal in the manner that regulators demand, such as not fully confined by leashing/chaining/caging or not registered; in this scenario, animals are being confiscated and then culled based on the behaviour of their owners.

Culling often involves cruel methods that cause significant suffering to animals. These methods, such as strychnine poisoning or shooting, are particularly distressing when carried out on the streets, where citizens, including children, may witness the suffering. Alternatively, authorities may collect animals from the streets and then cull within shelter facilities away from public view, where the methods used may be different but also can be inhumane, such as gassing with exhaust fumes, injections of air embolisms or toxins that cause death but without prior lack of consciousness. Culling may be indirect, as in the case of relocation of dogs or cats away from the point of capture and to an area where they are perceived to be less of a nuisance but with minimal food, water or shelter resources leading to a slow but inevitable death.

Culling differs from euthanasia, which focuses on the current and predicted welfare of an individual animal with the goal of ending suffering. Euthanasia, by definition, must always involve humane methods as outlined in article 7.7.27 of WOAH’s Chapter 7.7, Dog Population Management of the Terrestrial Animal Health Code. ICAM’s guide to developing a euthanasia policy with an animal welfare basis supports participatory and objective policy development with individual animal welfare as the priority consideration, taking note of the potential to return or rehome and the resources required to provide veterinary treatment and ongoing care to maintain good welfare. Euthanasia is part of humane population management and will be essential for all services that involve direct animal handling, including sterilisation programmes, rehoming centres and provision of veterinary services, to prevent animal suffering.

1. Create a multi-stakeholder task force that will drive forward improvements in population management towards achieving agreed impacts/goals of this population management system.
2. Establish the sources of free-roaming and unwanted dogs or cats within the community; breeding on the streets, abandonment, loss and roaming of owned animals, and the human behaviours that are driving these sources. Note that this will differ between country and communities within countries.
3. Identify which services will address the priority sources active in the community; reproduction control (of owned and/or unowned animals), accessible veterinary services, controls of commercial breeding and sale, identification and registration and rehoming.
4. Conduct a gap analysis between what is currently being done to manage the population and what is now understood to be needed; identify improvements to legislation and enforcement, professional capacity, community engagement, funding and infrastructure to deliver the population management system.
5. Develop and implement a strategy and action plan to implement these improvements and monitor progress against the stated impacts.

• There is no single population management system that fits all communities, there will be necessary variation to match the differences in the sources of free-roaming dog/cat populations and drivers of those sources. Hence, costs will also vary. Where Trap (cat)/Catch (dog), Neuter, Vaccinate and Return is used as one action to manage the population there are some cost estimates available: e.g. Cat TNVR was estimated to range from 20-97 USD per cat Benka and Boone et al (2021) and CNVR has been estimated to start at 25 USD per dog (pers comm).
• Where adoption through rehoming centres is used to manage the current free-roaming animals, the cost per animal will be higher: e.g. Cat rehoming was estimated to range from 104-550 USD per cat Benka and Boone et al (2021), approximately 5 times their estimate of per cat costs of TNVR.
• It should be recognised that population management of dogs and cats is not a short-term project, this is a system of services that will always need to be in place. The services required may change over time as animal ownership and acquisition changes, including increases in rates of adoption and owner investment in veterinary services for their animals.

• The economic savings from managing animal populations are most apparent where canine rabies transmission is a significant burden on the health services; treatment of a suspect bite costs 11-150 USD, but the majority of the economic burden comes from productivity losses from premature deaths (Hampson et al 2015). A dog population management project in Jaipur, India was calculated to have made direct economic savings of 5.62 million USD from fewer dog bites and fewer clinical human rabies cases requiring treatment over 23 years. Including productivity losses from premature deaths increased the estimated economic savings to 38.48 million USD (Larkins et al 2020).
• Where rabies is less prevalent, savings will still be made through dog bite avoidance as dogs bite for reasons other than rabies symptoms; as few as 1% of bites treated as suspected rabies transmissions are estimated to actually be from rabid dogs (CDC analysis of reported bites in Haiti and Philippines). The same project in Jaipur identified seasonality in reported bites and proposed that many bites were motivated by maternal defensive aggression or puppies biting out of fear or play, hence much of bite reduction they had achieved was due to sterilisation removing these motivations (Reece et al 2013).
• Where social costs are considered, there is potential for an improved perception of safety and walkability of streets due reduced density of free-roaming dogs and changes in their behaviour following sterilisation (e.g. Citizens in Colombo, Sri Lanka reported fewer problems related to dogs following a 5 year DPM project, in particular reductions in problems relating to breeding behaviours and puppies, and rabies; Hasler et al 2014).

• The speed of change depends on the intensity of implementation and whether sources of dogs and cats on the streets are tackled simultaneously whilst addressing the current free-roaming animals. For example, CNVR was used in Bangkok along with sterilisation of owned dogs, the reduction in the density of dogs was measured to be statistically significant and noticeable to citizens within 5 years (Hiby et al 2023). However, benefits may be felt earlier due to changes in animal behaviour; reductions in breeding behaviours and reductions in puppies/kittens with high mortality will be apparent within one breeding season.

• Monitoring progress of population management depends on what impacts are desired. In ICAM’s ‘Are we making a difference?’ we identify 8 commonly stated impacts of DPM and provide a recommended and suggested list of indicators and methods of measurement. Where rehoming is used to manage animal populations, intake and euthanasia/adoption statistics will be used to measure progress. Where dogs and cats are managed in situ on the streets, changes in the density of free-roaming animals along standard routes can be used instead. Impacts on people are often measured using dog bite incidence and number and nature of animal-related complaints to municipalities.

• ICAM has developed two free online courses to support planning of dog population management; our ‘DPM for Policymakers’ course provides a brief introduction to DPM and outlines policy implications, whilst the ‘Implementing DPM’ course explores how a DPM system can be designed, implemented and monitored.

• See About ICAM
• The International Companion Animal Management (ICAM) coalition brings together international Non-Governmental Organisations (NGOs) with a focus on animal welfare, rabies elimination and small animal veterinary services. This coalition is united behind the goal of supporting the development and use of humane and effective dog and cat population management worldwide.
• We share experiences, ideas and knowledge on dog and cat population dynamics and management to coordinate and improve our recommendations and guidance. Each organisation has agreed it is important that we strive to improve our mutual understanding through collaboration. We have a responsibility as project implementers, funders, advocates and advisors to ensure we are offering the most accurate guidance, based on the latest available data and concepts, to those involved with population management in the field. We also believe that it is important to be transparent and to document our opinions and philosophy whenever possible.