Sources

Reviews and overviews

Reviews look across multiple studies. They are a useful place to begin before getting lost in the details of one paper.

• Review of Dog Training Methods: March 2023 update. A broad, readable evidence review prepared for AnimalKind.
• The effects of using aversive training methods in dogs: A review. A peer-reviewed overview of the research available at publication.
• Do aversive-based training methods actually compromise dog welfare? A literature review. A review focused specifically on welfare outcomes.
• Working Dog Training for the Twenty-First Century. A narrative review connecting learning theory, welfare, selection, and performance in working dogs.
• Canine Socialisation: A Narrative Systematic Review. A review of 29 studies on socialisation and later behavior, including the limits and gaps in the evidence.
• Communication in Dogs. A review of visual, vocal, and olfactory communication. It does not show that human-imposed aversive training replicates dog-to-dog communication.
• The voice of choice: A scoping review of choice-based animal welfare studies. Rust, Clegg and Fernandez (2024). A scoping review of choice experiments with zoo, farm and laboratory animals. Most included studies reported welfare benefits from opportunities to choose.
• Maternal behaviour in domestic dogs. Lezama-García and colleagues (2019). A review of mother-puppy interactions, maternal care and development.
• A review of maternal behaviour in dogs and potential areas for further research. Santos, Beck and Fontbonne (2020). A review of maternal care and puppy development, including how care is measured and what remains uncertain about its lasting effects.
• Applying animal learning theory: training captive animals to comply with veterinary and husbandry procedures. Young and Cipreste (2004). An applied discussion of teaching animals to participate in routine veterinary and husbandry procedures through learning and reinforcement. It describes practical alternatives to physical punishment and forced handling across a range of species.

Training methods, welfare, and the relationship

These studies examine behavior, stress, learning, emotional state, or the dog-human relationship under different training approaches.

• Dog training methods: Their use, effectiveness, and interaction with behaviour and welfare. An owner survey examining methods, obedience, and reported problem behavior.
• Training methods and owner-dog interactions: Links with dog behaviour and learning ability. An observational study of training history, interactions, and performance on learning tasks.
• Survey of confrontational and non-confrontational training methods in client-owned dogs. An owner survey that also recorded aggressive responses associated with the interventions used.
• Effects of two training methods on stress-related behaviors and the dog-owner relationship. A comparison of training approaches using observed behavior and attention to the owner.
• Does training method matter? Evidence for the negative impact of aversive-based methods on companion dog welfare. A study using behavioral observations, cortisol, and cognitive-bias testing.
• Carrots versus sticks: The relationship between training methods and dog-owner attachment. A study focused on training style and measures of attachment.
• Dogs are more pessimistic if their owners use two or more aversive training methods. A cognitive-bias study examining emotional state and reported training practices.
• Behaviour of smaller and larger dogs: Effects of training methods, inconsistency, and engagement. A large owner survey examining several factors together.
• Reinforcer effectiveness in dogs—The influence of quantity and quality. Riemer and colleagues (2018). Dogs ran faster for a preferred food type in a runway task, while increasing dry-food quantity from one piece to five did not significantly change running speed. The study highlights the value of finding rewards your dog cares about.
• Incentive motivation in pet dogs – preference for constant vs varied food rewards. Bremhorst and colleagues (2018). In a choice experiment with 16 dogs, preferences for a favorite treat or a varied selection differed among individuals, and interest in variety increased over the session. Your dog’s preferences and motivation can change as you train.
• Effectiveness of marker training for detection dogs. Lazarowski and colleagues (2025). In 28 candidate detection dogs, adding a clicker to reward-based training reduced the trials needed to complete training and improved the precision of the alert response. It shows how timely feedback can help dogs understand exactly what earned a reward.
• Can I touch you? A pilot study comparing consensual and non-consensual human-dog touch interactions. Sarrafchi and colleagues (2025). When therapy dogs could choose whether to be touched, they moved away more often but still spent most of the session within reach of people. More ears-back behavior during forced touch underscores why staying nearby is not a substitute for giving your dog a choice.

Remote electronic collars

This section keeps the direct comparisons, field research, surveys, and published academic discussion together.

• Training dogs with the help of the shock collar: Short- and long-term behavioural effects. A field study comparing the behavior of dogs with and without prior shock-collar training.
• The use of electronic collars for training domestic dogs. A UK owner survey covering prevalence, reasons for use, risk factors, and perceived success.
• Welfare consequences and efficacy of remote electronic training collars compared with reward-based training. A controlled field study available free in full.
• Efficacy of dog training with and without remote electronic collars versus a focus on positive reinforcement. Read the original study, the published commentary, and the author response together.
• Electronic training devices: Discussion of their use as a basis for the ESVCE position statement. A review and professional discussion from veterinary clinical ethology.
• Questionnaire survey on the use of different e-collar types in France. A survey of everyday use intended to inform possible regulation.
• Training methods of military dog handlers and their effects on team performance. An observational study of working-dog teams, handler behavior, dog behavior, and performance.

Fear, aggression, and behavior treatment

Behavior problems do not exist in a vacuum. These papers look at risk factors, professional treatment, and behavior modification in more complex cases.

• Reactive and risky: The behavioural structuring of ‘dog reactive dogs’. An owner questionnaire found four behavior profiles within dogs described as dog-reactive. It supports treating reactivity as heterogeneous, not using a label as an individual diagnosis.
• Excessive energy in dogs: The impact of caregiver-related variables and fear/anxiety. An online questionnaire found associations among reported excessive energy, dog age, caregiver stress, attitudes toward aversive training, and fear or anxiety.
• Human-directed aggression in domestic dogs: Occurrence in different contexts and risk factors. A large UK owner survey.
• Inter-dog aggression in a UK owner survey. Research on prevalence, co-occurrence across contexts, and risk factors.
• It is mine! Clicker training as a treatment of object guarding in four companion dogs. A case series involving four companion dogs.
• A review on mitigating fear and aggression in dogs and cats in a veterinary setting. A free full-text review focused on veterinary handling and care.
• A survey of dog behavior-modification practice in the UK. Research on who provides services, the methods reported, and client-perceived effectiveness.
• Effectiveness of professionals and behavior-modification programs for canine aggression. An investigation of programs with and without medication.
• Owner and animal factors predict problematic behaviors and owner reactions. A study examining both sides of the human-dog relationship.
• Food-related aggression in shelter dogs: A comparison of behavior identified by a behavior evaluation in the shelter and owner reports after adoption. This shelter study supports cautious interpretation of food-guarding tests; it does not predict every dog’s behavior after adoption.
• Breed differences in canine aggression. Duffy, Hsu and Serpell (2008). A questionnaire study comparing reported aggression across breeds and situations.
• Effect of a Standardized Four-Week Desensitization and Counter-Conditioning Training Program on Pre-Existing Veterinary Fear in Companion Dogs. Stellato and colleagues (2019). A four-week program of gradual handling practice and positive clinic visits reduced some signs of veterinary fear. The study helps connect preparation at home with more comfortable veterinary care, while showing that a short, standardized program may need to be extended or tailored to your dog.
• Potential Benefits of a ‘Trauma-Informed Care’ Approach to Improve the Assessment and Management of Dogs Presented with Anxiety Disorders. Corridan, Dawson and Mullan (2024). Makes the case for understanding fearful and reactive dogs through their past experiences, protecting them from further distress and supporting their caregivers. It brings trauma-informed care into canine behavioral assessment while keeping medical causes, including pain, in view.

Health, emotion and cognition

These studies examine fear, pain, early experiences, social support and cognition, helping us understand more about what your dog may be experiencing.

• Owner-reported prevalence and severity of fear and anxiety in dogs (Beaver, 2026). An analysis of Dog Aging Project questionnaires covering 43,517 U.S. dogs describes reported fear across everyday situations. Discussed in my video about understanding fear.
• The abilities in dog pain sign recognition as assessed by presenting seventeen listed dog behavioural signs and three case descriptions to dog owners and non-dog owners (Gardeweg, Picard and van Herwijnen, 2026). In a Dutch questionnaire completed by 647 people, subtle signs of pain were harder to recognize than obvious ones. Useful context when a change in behavior may call for a veterinary assessment. Discussed in my video about pain and behavior.
• Early life adversity in dogs produces altered physiological and behavioral responses during a social stress-buffering paradigm (Buttner, Awalt and Strasser, 2023). A study of 45 dogs examined reactions to a threatening stranger with either their guardian or an unfamiliar person present. Dogs with adverse backgrounds showed more relaxed behavior and sought more contact when their guardian was present. Discussed in Does “Tough Love” Help Dogs?
• The gut microbiome correlates with conspecific aggression in a small population of rescued dogs (Canis familiaris) (Kirchoff, Udell and Sharpton, 2019). An exploratory study of 31 rescued, shelter-housed dogs linked gut microbiome composition with aggression toward other dogs. The small, selected sample calls for replication in other populations. Discussed alongside the next paper in my video about the microbiome and behavior.
• Gut microbiome structure and adrenocortical activity in dogs with aggressive and phobic behavioral disorders (Mondo et al., 2020). An observational comparison of 42 shelter dogs found differences in gut bacteria across behavioral profiles. Together, these two studies identify associations that need further investigation to establish causes or effective treatments.
• Neural evidence for referential understanding of object words in dogs (Boros et al., 2024). An EEG study of 18 dogs found different brain responses when familiar object names were followed by matching or mismatched objects, supporting an understanding of those familiar words. Discussed in my video about dogs understanding words.
• Evaluating the effects of a temporary fostering program on shelter dog welfare. Gunter and colleagues (2019). Across five U.S. shelters, dogs had lower cortisol and longer uninterrupted rest during brief foster stays. Cortisol returned to baseline after they returned, showing both the benefit of a break and the importance of conditions inside shelters.
• Levels of maternal care in dogs affect adult offspring temperament. Foyer, Wilsson and Jensen (2016). A study of German Shepherd litters found associations between early maternal care and later social engagement, physical engagement and aggression scores.
• Early Life Experiences and Exercise Associate with Canine Anxieties. Tiira and Lohi (2015). A Finnish questionnaire study found links between reported anxiety, puppyhood experiences and daily exercise.
• Effects of Environmental Enrichment on Dog Behaviour: Pilot Study. Hunt, Whiteside and Prankel (2022). A pilot study of ten assistance dogs compared behavioral changes after seven enrichment activities. Responses differed across activities, with play and social opportunities producing substantial changes.
• Prevalence, comorbidity, and breed differences in canine anxiety in 13,700 Finnish pet dogs. Salonen and colleagues (2020). A large Finnish questionnaire study examined reported anxiety-related behaviors, their overlap and differences between breeds.
• Canine hyperactivity, impulsivity, and inattention share similar demographic risk factors and behavioural comorbidities with human ADHD. Sulkama and colleagues (2021). A further analysis of the same Finnish questionnaire data linked hyperactivity, impulsivity and inattention with demographic characteristics, daily life and other reported behaviors, exploring similarities with human ADHD.
• Age-related effects on a hierarchical structure of canine cognition. Bognár and colleagues (2024). Cognitive testing in 129 pet dogs, with follow-up in 99, identified shared patterns across learning and problem-solving tasks. The study examined how age, health and individual characteristics relate to performance and change over time.
• Risk factors and behaviors associated with separation anxiety in dogs. Flannigan and Dodman (2001). A case-control study of 400 behavior-clinic records found that attachment-related behaviors were associated with separation anxiety.
• Disambiguating the “guilty look”: Salient prompts to a familiar dog behaviour. Horowitz (2009). In an experiment with 14 dogs, behaviors people called a guilty look were more closely related to scolding than to whether the dogs had disobeyed.
• Behavioural changes in dogs treated with corticosteroids. Notari, Burman and Mills (2015). Guardians reported more fearfulness and aggression and less play during corticosteroid treatment. In behavioral testing, dogs receiving corticosteroids ate less after a recorded growl than control dogs. The study shows why medication belongs in the conversation when your dog’s behavior changes.
• Gastrointestinal disorders in dogs with excessive licking of surfaces. Bécuwe-Bonnet and colleagues (2012). A prospective clinical study found gastrointestinal abnormalities in 14 of 19 dogs brought in for excessive surface licking. It illustrates why a behavior concern can deserve a veterinary assessment.
• Genetic mapping of canine fear and aggression. Zapata, Serpell and Alvarez (2016). Using breed-average behavior data, this study identified genetic associations with fear and aggression, including variants also linked to small body size. It adds evidence for inherited influences on behavior and for treating different forms of aggression as distinct problems.
• Sleep in the dog: comparative, behavioral and translational relevance. Bódizs and colleagues (2020). Brings together research on canine sleep, memory, emotional experiences and aging. It explains why rest and a comfortable place to sleep belong in a serious conversation about your dog’s learning and welfare.
• EEG Transients in the Sigma Range During non-REM Sleep Predict Learning in Dogs. Iotchev and colleagues (2017). In 15 companion dogs, brief bursts of brain activity during sleep were associated with improvement in remembering newly learned verbal cues. The study gives a window into what your dog’s brain is doing after a lesson ends.
• Sleep-spindles as a marker of attention and intelligence in dogs. Iotchev and colleagues (2024). Sleep recordings and cognitive tests in 58 companion dogs linked features of sleeping brain activity with sustained attention and broader cognitive performance. These relationships were observed again three months later, adding to the evidence connecting sleep and cognition.
• Neural mechanisms for lexical processing in dogs · 2017 correction. Andics et al. (2016). In an awake brain-imaging study of 13 companion dogs, familiar praise words and tone of voice produced distinct responses. Reward regions responded most strongly when praise words were delivered in a praising tone.

Canine senses and communication

• When the Nose Doesn’t Know: Canine Olfactory Function Associated With Health, Management, and Potential Links to Microbiota (Jenkins, DeChant and Perry, 2018). A narrative review of canine smell and its relationship to health, management and potentially the gut microbiome. I cited it for the anatomy graphic in my leash-pulling video.
• Left gaze bias in humans, rhesus monkeys and domestic dogs (Guo et al., 2009; published online in 2008). A comparative visual-attention study found a left-gaze bias in dogs looking at human faces. Discussed in my video about dogs reading faces.
• Evolution of facial muscle anatomy in dogs (Kaminski et al., 2019). Comparing dog and wolf anatomy and facial movements, the researchers proposed that human preferences helped shape dogs’ expressive eyebrows. Discussed in my video about “puppy dog eyes”. The two later studies below challenge a domestication-only explanation.
• Raising an Eye at Facial Muscle Morphology in Canids (Sexton et al., 2024). A preliminary anatomical comparison of ten canid specimens found the relevant eye muscles outside domestic dogs, raising questions about how these muscles evolved.
• Coyotes can do ‘puppy dog eyes’ too: comparing interspecific variation in Canis facial expression muscles (Cunningham et al., 2024). Finding a well-developed inner-brow-raising muscle in coyotes supports the possibility that this feature was inherited from an earlier common ancestor, rather than arising through dog domestication.
• The Domestication of Social Cognition in Dogs. Hare and colleagues (2002). Comparative experiments found that dogs, including young puppies, used human cues to locate hidden food. The authors proposed that domestication helped shape these social abilities.
• Canine Olfaction: Physiology, Behavior, and Possibilities for Practical Applications. Kokocińska-Kusiak and colleagues (2021). A review of how dogs gather and use scent information, covering nasal anatomy, sniffing, communication and factors that affect smell.
• Methodological Considerations in Canine Olfactory Detection Research. Lazarowski and colleagues (2020). Examines how blinding, odor samples, task design, handler influence and accuracy measures affect what canine detection studies can tell us.
• Dogs can discriminate between human baseline and psychological stress condition odours. Wilson and colleagues (2022). In a double-blind experiment, four trained dogs distinguished combined breath and sweat samples taken before and after a stressful task.
• Dogs display owner-specific expectations based on olfaction. Bräuer and Blasi (2021). Dogs showed more activity when a familiar person at the end of a scent trail differed from the person whose trail they had followed, suggesting expectations about who they would find.
• Scent of the familiar: an fMRI study of canine brain responses to familiar and unfamiliar human and dog odors. Berns, Brooks and Spivak (2015). In 12 awake dogs, the scent of a familiar person produced the strongest response in a brain region associated with positive expectations. The study connects dogs’ social relationships with the way they process smell.
• Conspecific recognition of pedal scent in domestic dogs. McClanahan and Rosell (2020). A controlled study of how dogs investigate scent collected from other dogs’ feet. Differences in sniffing and nostril use support a role for paw scent in communication.
• Do dogs get the point? A review of dog–human communication ability. Kaminski and Nitzschner (2013). A review of how dogs use human gestures, attention and context to understand communication. It examines the cognitive mechanisms involved and how domestication may have shaped these abilities.
• The value of sniffing: A scoping review of scent activities for canines. Fountain and colleagues (2025). A review of 27 studies asks what scent activities do for dogs themselves, including changes in behavior and physiology. It brings welfare into a field often focused on how well dogs perform detection tasks.
• The odour of an unfamiliar stressed or relaxed person affects dogs’ responses to a cognitive bias test. Parr-Cortes and colleagues (2024). In an experiment with 18 dogs, those exposed to human stress odour in their final testing session became more cautious about approaching an uncertain food location. The findings show how human stress signals can affect dogs without spoken words or visible body language.
• How do soundboard-trained dogs respond to human button presses? An investigation into word comprehension. Bastos and colleagues (2024). In two experiments involving 59 soundboard-trained dogs, play and outside words prompted relevant behavior even when an unfamiliar person pressed the buttons. The study tested responses to human-produced words, helping distinguish learned word associations from reactions to a guardian’s other cues.
• Soundboard-trained dogs produce non-accidental, non-random and non-imitative two-button combinations. Bastos and colleagues (2024). Reports of 194,901 button-pressing events from 152 dogs revealed recurring two-button combinations that were not explained by random pressing or simple imitation of guardians. This observational study supports deliberate button use while leaving the meanings and communicative intentions behind particular combinations open to further testing.
• A citizen science model turns anecdotes into evidence by revealing similar characteristics among Gifted Word Learner dogs. Dror and colleagues (2023). A five-year search identified 41 dogs whose knowledge of toy names was confirmed in supervised tests. Most guardians reported that this unusual ability first emerged during play, without deliberate word training. The study explores exceptional word learning across several breeds and how it develops in everyday relationships.
• Let me sniff! Nosework induces positive judgment bias in pet dogs. Duranton and Horowitz (2019). Dogs who practiced nosework for two weeks became more optimistic on a judgment-bias test; the heelwork group did not show the same change. The findings support making room for sniffing and independent exploration in your dog’s life.

The training profession and humane-practice adoption

Training choices are shaped by education, professional culture, regulation, ethics, and the way people interpret evidence. These sources examine that wider context.

• Dog Owners’ Use of Training Methods and Their Ethical Stance on the Treatment of Animals. A survey of 500 included US dog owners found associations between ethical orientation and reported use of positive training or physical correction.
• Professional dog trainers’ perspectives on training methods: Ethical and evidentiary insights. A 2026 study comparing how reward-based and mixed-method trainers discuss evidence, ethics, welfare, effectiveness, and regulation. The publisher later corrected a Table 2 value, a section-heading typo, and the conflict-of-interest disclosure.
• Barriers to the adoption of humane dog-training methods. Research on factors that can make evidence-based practice harder to adopt.
• Examination of the Accuracy and Applicability of Information in Popular Books on Dog Training. A study examining training advice in five then-bestselling books.
• The least inhibitive, functionally effective (LIFE) model: A new framework for ethical animal training practices. Fernandez (2024). An ethical framework that evaluates animal training through behavioral function, meaningful choice and welfare, with an emphasis on expanding what animals can do rather than simply suppressing behavior.
• Resolution on Physical Discipline of Children by Parents. American Psychological Association (2019). APA’s resolution draws on research on child development to oppose physical discipline and support nonviolent approaches.
• Corporal punishment by parents and associated child behaviors and experiences: A meta-analytic and theoretical review. Gershoff (2002). A meta-analysis linked parental corporal punishment with greater immediate compliance, more aggression and poorer mental health in children. It also examines possible explanations for those relationships. Gershoff’s reply to the accompanying commentaries addresses the definitions, causal questions and evidentiary standards raised by responses to the meta-analysis.
• Training Technologies. Science, Gender and Dogs in the Age of Positive Dog Training. Gabrielsen (2017). Social research on how training practices, scientific authority, technology and gender shape relationships between people and dogs.
• Training Dogs with Science or with Nature? An Exploration of Trainers’ Word Use, Gender, and Certification Across Dog-Training Methods. Johnson and Wynne (2023). An analysis of 100 dog trainers’ websites in ten US cities found substantial differences in how trainers describe their methods, with reward-based trainers more likely to hold certification. It explains why reassuring language alone is not enough when choosing someone to work with your dog.
• Spanking and Child Outcomes: Old Controversies and New Meta-Analyses. Gershoff and Grogan-Kaylor (2016). A meta-analysis covering more than 160,000 children found that spanking was associated with harmful outcomes, including greater aggression and poorer mental health. It examines spanking separately from broader physical abuse.

Police dogs, injury and institutional power

Research, public records and historical scholarship on injuries, dog welfare and the use of dogs in racial and institutional violence. I bring these connections together in Weaponized Dogs.

• The demographics of dog bites due to K-9 (legal intervention) in the United States. Loder and Meixner (2019). A national emergency-department study estimated 32,951 visits for police-dog bites during 2005–2013 and examined who was injured.
• Weaponizing Dogs: The Brutal and Outdated Practice of Police Attack Dogs. ACLU California Action (2024). Analysis of official data, policies and public records from 37 California agencies, including racial disparities and serious injuries.
• Unleashed Brutality: An Expert Medical Opinion on the Health Harms from California Police Attack Dogs. Physicians for Human Rights (2024). Physicians reviewed 30 selected California cases to document physical and psychological harms. The available records varied; six cases included medical documentation.
• Racial Disparity in Consent Searches and Dog Sniff Searches. ACLU of Illinois. An analysis of Illinois traffic-stop records, including 2012 and 2013 dog-sniff data, examining racial disparities and whether searches found contraband.
• Handler beliefs affect scent detection dog outcomes. Lit, Schweitzer and Oberbauer (2011). In an experiment with 18 detection teams and no target scents present, handlers’ expectations influenced reported alerts.
• Working Dogs: Federal Agencies Need to Better Address Health and Welfare. U.S. Government Accountability Office (2022), GAO-23-104489. A federal audit examining whether working-dog policies, contracts and overseas-program standards addressed health and welfare needs.
• Evaluation of the DoD Military Working Dog Program’s Management of Canine Welfare. Inspector General report DODIG-2026-057. An evaluation of military working-dog care, with a focus on dogs in non-training status in the examined program.
• Assessing the welfare of kennelled dogs—A review of animal-based measures. Polgár, Blackwell and Rooney (2019). A review of behavioral, physiological and cognitive ways to assess kennel welfare, including how individual differences affect interpretation.
• Canines: Enforcing Race & State. Parry and Yingling (2025). Historical scholarship connecting the use of dogs in enslavement, racial control, prisons, policing and colonial power.
• Between race and animality: European borders, ‘colonial dogs’, and the policing of humanity. Brito (2024). Scholarship examining police dogs at European borders through the histories of colonialism, racial hierarchy and violence against migrants.
• De-fanged. Adams and colleagues (2024). A natural experiment tracked injuries and resistance after a U.S. city suspended its police dog apprehension program. The suspension was not associated with increases in those outcomes during felony arrests.
• The Racialized Violence of Police Canine Force. Wasilczuk (2023). Legal scholarship tracing police canine force through slavery, racial violence and constitutional doctrine, and examining the case for abolishing apprehension dogs.
• Breeding Racism: The Imperial Battlefields of the ‘German’ Shepherd Dog. Skabelund (2008). Examines how German shepherds became part of nationalism and racial hierarchy in the imperial projects of Germany and Japan.
• ‘You Should Give Them Blacks to Eat’: Waging Inter-American Wars of Torture and Terror. Johnson (2009). Traces the use of dogs to terrorize enslaved people and the cooperation among colonial powers that sustained it.
• War Unleashed: The Use of War Dogs During the Haitian War of Independence. Girard (2012). An archival history of French forces’ use of dogs during Haiti’s war of independence, connecting military violence with the attempt to restore slavery.
• Guidance on Policies and Practices for Patrol Canines. Police Executive Research Forum (2020). Covers patrol canine deployment, apprehension, handler selection, training and review.
• Canicide by Cop: A geographical analysis of canine killings by police in Los Angeles. Bloch and Martínez (2020). Analysis of LAPD and Los Angeles County Sheriff’s Department shootings from 2010–2017 found that dog shootings and killings clustered in low-income communities of color. The study places violence against dogs within the wider geography of state violence.
• K-9 Catch-22: The Impossible Dilemma Of Using Police Dogs In Apprehension Of Suspects. Schiavone (2019). Examines how a person’s attempt to defend themselves from an attacking police dog can become grounds for further police force. The article connects this trap to the racial history of police dogs and the risks imposed on both people and dogs.
• The Fourth Amendment and the Police Use of Pain Compliance Techniques on Nonviolent Arrestees. Whipple (1991). Argues that inflicting pain on a passively resisting person is an unreasonable seizure when less injurious ways to carry out the arrest are available. It challenges the use of pain simply to force compliance.
• More than Just Collateral Damage: Pet Shootings by Police. Lee (2018). Examines how encounters with family dogs become police shootings, and the barriers to measuring their scale or securing accountability. The article brings together cases, legal analysis and reporting on the harm to animals, families and bystanders.
• Households With a White, Non-Hispanic Householder Were Ten Times Wealthier Than Those With a Black Householder in 2021. U.S. Census Bureau (2024). Using 2021 household data, this report documents a roughly tenfold gap in median wealth between households with White, non-Hispanic householders and those with Black householders. It also examines differences in assets and debt that help sustain the racial wealth gap.
• One in Five: Ending Racial Inequity in Incarceration. Ghandnoosh, The Sentencing Project (2023). Documents the scale of mass incarceration and persistent racial disparities, including how sentencing and enforcement policies shape who is imprisoned. It places recent reductions alongside the much larger expansion that preceded them.
• An Indigenous Peoples’ History of the United States. Dunbar-Ortiz (2014). A history of the United States centered on Indigenous peoples, tracing how land seizure, settler colonialism and organized resistance shaped the country. It connects the national founding story to the institutions and violence that followed.
• From hunters to hell hounds: the dogs of Columbus and transformations of the human-canine relationship in the early Spanish Caribbean. Ensminger (2022). Traces how dogs brought to the early Spanish Caribbean became instruments of colonial warfare, punishment and social control.
• Slave Hounds and Abolition in the Americas. Parry and Yingling (2020). Traces how slaveholders across the Americas used dogs to pursue people escaping slavery, and how resistance to those attacks helped fuel abolitionist movements.

One Health, One Welfare and shared environments

Your dog’s life is connected to your own and to the conditions around you. These sources inform the One Health and One Welfare discussion through research on health, welfare and stress.

• One Health: A new definition for a sustainable and healthy future. One Health High-Level Expert Panel and colleagues (2022). A consensus definition connecting the health of humans, animals, plants and ecosystems.
• One Welfare – a platform for improving human and animal welfare. García Pinillos and colleagues (2016). A framework linking animal welfare, human wellbeing and the environments we share.
• Long-term stress levels are synchronized in dogs and their owners. Sundman and colleagues (2019). Hair-cortisol measurements from 58 human-dog pairs found an association in long-term stress levels. The study involved border collies, Shetland sheepdogs and their female guardians.
• The Welfare of Dogs as an Aspect of the Human–Dog Bond: A Scoping Review. Verbeek and colleagues (2024). A scoping review examining how research on the human-dog bond addresses dogs’ welfare, and where dogs’ experiences receive too little attention.
• Updating Animal Welfare Thinking: Moving beyond the “Five Freedoms” towards “A Life Worth Living”. Mellor (2016). Explains how the Five Domains approach to welfare assessment can account for positive experiences as well as suffering.
• Searching for Animal Sentience: A Systematic Review of the Scientific Literature. Proctor, Carder and Cornish (2013). Maps scientific research on animals’ subjective experiences, including gaps in work on positive emotions and less-studied species.
• How Death Outlives War: The Reverberating Impact of the Post-9/11 Wars on Human Health. Savell (2023). Brown’s Costs of War report traces how post-9/11 wars keep killing through destroyed healthcare, hunger, environmental damage and lasting trauma. It estimates 3.6–3.8 million indirect deaths in Afghanistan, Pakistan, Iraq, Syria and Yemen.
• Racial Disparities in Animal Welfare. University of Tennessee’s Program for Pet Health Equity, for CARE (2024). Research in four US communities found racial disparities in pet adoption and documented how housing, income, transportation and access to veterinary care shape who can keep or adopt an animal. It connects everyday animal welfare policies to systemic inequity.
• Is access to euthanasia drugs and moral stress linked to suicide rates in veterinarians? A cross-sectional national survey and network analysis. Rymaszewska and colleagues (2026). In a survey of 783 Polish veterinarians, 41.6% met the screening threshold for suicide risk. The authors call for prevention that combines accessible mental health support with changes to workplace access to lethal drugs.
• Animal Abuse as an Indicator of Domestic Violence: One Health, One Welfare Approach. Mota-Rojas and colleagues (2022). Reviews the links between animal abuse and violence within families, including harm to companion animals as a means of coercive control. It argues for veterinarians, health professionals and social services to recognize and respond to these connected forms of violence.

Wildlife and public policy

Sources for my reporting on M-44 cyanide devices and wolf protections, including wildlife research and the records of government killing programs.

• Demographic and Spatial Responses of Coyotes to Changes in Food and Exploitation. Gese (2005). Conference research following 92 radio-collared coyotes in southeastern Colorado examined population and spatial responses to food availability and removal.
• A history of toxicant ejectors in coyote control. Connolly (2002). A technical history of coyote getters and M-44 devices, including their development and use in government wildlife programs.
• BLM–APHIS Wildlife Services Master Memorandum of Understanding (2026). The interagency agreement governing wildlife-damage work on BLM land, available as a government-document copy hosted by DocumentCloud.
• M-44 Cyanide Capsules: EPA product label. The label accepted August 23, 2023, for EPA registration 56228-15. It specifies permitted uses, handling requirements, warning signs and placement restrictions.
• Wildlife Services Program Data Reports. USDA APHIS’s annual reporting portal for Wildlife Services activities. Use the report year and method-specific categories when comparing animal deaths; the agency may revise its data.
• Supporting America’s Ranchers. Executive Order 14425, September 4, 2026. Section 3 directs a review of wolf recovery criteria and possible further action on federal protection and predator policy.
• Gray Wolf Recovery News and Updates. U.S. Fish and Wildlife Service. The agency’s current account of gray-wolf recovery and federal protection, including regional differences in legal status.