Blackwell's Five-Minute Veterinary Consult Clinical Companion: Canine and Feline Behavior

By Debra F. Horwitz

Blackwell’s Five-Minute Veterinary Consult Clinical Companion: Canine and Feline Behavior, Second Edition offers fast access to reliable, practical information on managing common behavior disorders in dogs and cats.

• Takes a new section approach to allow for easier browsing
• Adds 19 new topics or algorithms covering separation anxiety, thunderstorm sensitivity, introducing pets to the family and each other, enrichment, geriatric behavior problems, handling techniques, urine marking, leash reactivity, pediatric behavior problems and best practices, and rescue pets
• Offers a comprehensive guide to diagnosing and managing behavior problems in dogs and cats
• Designed for fast access to information, with identically formatted topics for ease of use
• Includes access to a companion website providing 43 client education handouts for download and use, including 25 brand-new handouts

• Language: English
• Publisher: Wiley
• Release date: Nov 3, 2017
• ISBN: 9781118854419

Book preview

Contributor List

Dr. Melissa Bain DACVB

Dr. Sara L. Bennett MS, DACVB

Dr. Jeanine Berger DACVB

Dr. John Ciribassi DACVB

Dr. Sagi Denenberg DACVB

Dr. Theresa L. DePorter BS,DACVB

Mandy Eakins KPA CTP

Dr. Elizabeth S. M. Feltes DACVB

Dr. Margaret Gruen DACVB

Dr. Lore I. Haug DACVB

Dr. Meghan Herron DACVB

Dr. Ellen M. Lindell DACVB

Dr. Rachel Malamed DACVB

Debbie Martin LVT, VTS (Behavior), CPDT-KA, KPA CTP

Dr. Kenneth Martin DACVB

Dr. Amy L. Pike DACVB

Dr. Lisa Radosta DACVB

Dr. Marsha Reich DACVB

Dr. Ilona Rodan DABVP (Feline)

Traci Shreyer MA

Dr. Carlo Siracusa DACVB

Dr. Meredith Stepita DACVB

Dr. Karen Sueda DACVB

Dr. Wailani Sung DACVB

Dr. Valarie Tynes DACVB

How to Use This Book

This edition has adopted a new approach, grouping chapters by disorder category, which should make it easier for the reader to reach the correct diagnosis. However, the outline of each chapter is the same as in the first edition, so that the reader can feel confident that all the information they need to diagnose and treat a behavioral disorder is right in front of them.

As veterinary healthcare professionals, whenever there is a change in behavior it is always essential to do our medical due diligence before moving on to a behavioral diagnosis, realizing that both can occur together, and that is how we begin with Chapter 1.

Aggression is a serious behavioral illness with numerous underlying motivations, and is dangerous both to humans and to other animals. The chapters on aggression are now grouped by species, with canine aggression being covered in Chapters 2–13, and feline aggression in Chapters 14–22.

Underlying most unwanted and undesirable behaviors in dogs and cats are anxiety, fear, and phobic disorders (Chapters 23–33). All of these types of illness are grouped together to facilitate diagnosis and treatment, since often more than one anxiety disorder may be present in a particular patient.

Next follows a section on compulsive and repetitive behaviors (Chapters 34–42), to help the reader to make the correct diagnosis and set up an appropriate treatment plan. These behavioral illnesses are usually abnormal, may occur in conjunction with medical disorders, and can have a negative impact on the animal's quality of life, welfare, and even their home.

The integration of pets into the home is often complex, as many homes have multiple pets of either the same or different species, or are combining families with pets. The aim of Chapters 8, 9, 16, 43, and 44 is to assist people in resolving the issues that may arise, and in addition several handouts are provided to help to facilitate a more harmonious integration. The key to creating harmony at home is enrichment, and Chapters 45 and 46 address this topic for dogs and cats, respectively.

Thanks to our medical expertise, cats and dogs are now living longer, but this often results in both medical and behavioral issues. Therefore an entire section is devoted to geriatric behavior problems (Chapters 47–49).

When routine care or treatment of an illness causes distress in our patients, the patient, the family, and the entire veterinary team are all affected. Three new chapters in this edition address patient-friendly and safe handling of dogs and cats (Chapters 50–52).

House soiling in dogs and cats is still a major reason for relinquishment of pets to a shelter, and an entire section of the book and several handouts are devoted to house soiling in unwanted locations (Chapters 53–57).

This is followed by a short section on mourning behavior in dogs and cats (Chapter 58).

Nuisance behavior problems are the numerous behaviors that may be normal but which are considered undesirable by the human family. There is an extensive section and treatment handouts on these behaviors and how to help to change them (Chapters 59–77).

Finally, information on puppies, kittens, and shelter and rescue pets is provided (Chapters 78–82).

In addition, it is hoped that the reader will find the four appendices very useful. They provide supplementary information on psychopharmacology (Appendix A) and learning and changing behavior (Appendix B), as well as history sheets and resources (Appendix C), and a set of 43 handouts (Appendix D), many of which have been written specifically for this second edition.

It is our hope that this new edition with its modified organization of chapters will help you to recognize and resolve behavioral illnesses and thus enable your patients to be kept in their homes well into old age.

Preface

The aim of the second edition of Blackwell's Five-Minute Veterinary Consult Clinical Companion: Canine and Feline Behavior is to be your practice companion, enabling you to integrate behavioral medicine as a routine part of your patient's healthcare plan. The treatment of behavioral illness has become increasingly important, as it remains one of the top reasons for pet relinquishment. Since the first edition of this book was published, much has changed in veterinary behavioral medicine, and the authors and I are eager to bring you up to date. All of the chapters have been either re-edited or completely rewritten, and the book has expanded from 64 to 82 chapters, with newly expanded appendices on pharmacology, learning and behavior modification, history sheets and resources, and a set of 43 handouts (of which 25 have been newly written for this edition). We have included information on how to make handling your patient safer, less stressful, and calmer for everyone—the veterinary team, the client, and above all, of primary concern to us, our patients.

This book is designed to help veterinarians answer behavior-related questions in any and every area of veterinary behavioral medicine. However, each chapter is designed for the general veterinarian rather than the specialist. It is essential to understand the significant role that safety and management can play in treating behavioral illnesses. Most importantly, we must remember that when a certain behavior is ongoing, the consequence of that behavior results in something desirable for the animal. The nature of that reward may be unclear to us, but it is nevertheless the case that behaviors which are rewarded are repeated.

When considering behavior problems and illnesses, it is important for us to understand that whether the behavior is desirable or undesirable, and whether it is normal or abnormal, whenever an animal performs a particular behavior, they have chosen it because they thought it was appropriate for the situation. This may not mean that we like the behavior, but neither does it mean that the animal is trying to be mean, spiteful, willful, stupid, or dominant. We need to move away from the idea of bad dog or bad cat, and instead ask why the pet has the need to perform this behavior. This requires us to look at the behavior from the pet's perspective. Therefore we must identify the underlying emotion—usually anxiety, stress, fear, or all three of these—and also consider other influences, such as environment, development, learning, and genetics.

Behavior tends to occur for one of the following reasons. It may be a normal but unwanted behavior (e.g., barking, scratching furniture, jumping up to greet people), which can often be helped by providing appropriate outlets for the behavior and/or by teaching new behaviors to replace the undesirable ones. Alternatively, the animal may be performing the behavior in order to change what they perceive to be the expected outcome of the social situation. In this case, it becomes important for us to try and understand why the animal perceives a different outcome to the one we anticipate, and how to change their underlying emotional state and teach them new tasks. This is the only way in which we can move forward with more desirable behaviors, and less fear, anxiety, and stress. By understanding the animal's perspective and their ethological basis for behavior we can provide better solutions. Finally, the animal might be suffering from a pathological state that is not under their control, such as a compulsive disorder, phobia, seizure, impulse disorder, or some other medical malady.

In cases of aggression, ensuring the safety of all those who might be in contact with the pet is the first priority. Safety precautions when followed can improve the quality of life for everyone involved, including the family and the pet. Management also plays a fundamental role in shaping behavioral change. Many behavior problems often continue because of the opportunity to repeatedly engage in the undesirable behavior. However, with appropriate management we can keep people safe, prevent the escalation of undesirable behaviors, and stop any reinforcement that the pet receives by engaging in the behavior.

Finally, in many situations we will need additional help from pheromones, nutraceuticals and other products, diets, and medication. The end result is that providing behavior services will save the lives of our patients.

Debra F. Horwitz

Acknowledgments

The creation of the second edition of Blackwell's Five-Minute Veterinary Consult Clinical Companion: Canine and Feline Behavior has taken place many years after the first, but would not have been possible without my previous co-author, Dr. Jacqueline Neilson DACVB, who was unable to join me in this new edition due to other work commitments. I have missed her in this role, but as the chapters have been rewritten and new ones added, and I have read through each chapter one final time, I could still hear her voice and tone in so many places. In reality, then, Jacqui's presence can be felt in this second edition, too, and I thank her again for her vital contributions to this book.

I also want to thank my editors at Wiley-Blackwell, especially Erica Judisch, Executive Editor, who never gave up until she had persuaded me to write this second edition. I am also grateful to Nancy Turner, Senior Project Editor, who helped me when I was struggling with the enormity of the task, and for all her editing once it was completed.

It would be remiss of me not to thank all my colleagues who reread, rewrote, and authored new chapters and handouts. Your insight was invaluable and has brought this book to a new level. Some of you took on entire sections of the book, which was a huge undertaking, and together we managed to keep a consistent voice from chapter to chapter. Thank you so much for all your hard work. However, every single author—regardless of whether they helped with one chapter or with a dozen or more—has brought a high level of professionalism and knowledge to this book. Collectively they have made this edition outstanding.

About the Companion Website

This book is accompanied by a companion website:

www.fiveminutevet.com/behavior

The website includes:

five history sheets and resources for downloading:

Behavior Resources

Canine Consultation Questionnaire

Clinician's Checklist

Feline Consultation Questionnaire

BSAVA Ladder of Aggression

43 client education handouts for downloading and use, including 25 new handouts written for this second edition:

Acute Management of Problem Behavior

Assessing Prognosis in Aggressive Dogs

Basic Principles for Children and Dogs

Basic Principles for Introducing Pets to a New Baby

Begging: How to Stop Begging at the Table

Bringing Home Your New Pet

Canine Body Language

Canine Enrichment

Carrier Training: Improving the Veterinary Visit for Your Cat

Creating Harmony in Homes with Multiple Cats

Desensitization and Counterconditioning: The Details

Feline Body Language

Feline Enrichment

Go to Place

Happy Veterinary Visits for Dogs

House Training: Teaching a Dog to Eliminate on Cue

House Training the Adult Dog

How to Reduce Food-Guarding Behavior in Dogs

How to Give Your Cat Medication

Instructions for Handling Feline Aggressive Events

Introducing Cats to One Another

Introducing Dogs to One Another

Jumping Up: Teaching Controlled Greetings

Kitten Socialization

Litter-Box Tips

Managing Noise and Storm Phobias

Markers and Reinforcers

Maximizing Treatment Success

Muzzle Training: Training Your Dog to be Comfortable Being Muzzled

Nail Trimming and Medicating Dogs and Cats

Puppy Socialization and Exposure

Safety Recommendations for Aggressive Animals

Senior Dogs and Cats: Improving Quality of Life

Separation Anxiety Treatment Protocol

Structuring Your Relationship with Your Pet

Target Training

Teaching a New Response to the Doorbell

Teaching a Puppy to Eliminate Outdoors

Teaching Drop It

Teaching Leave It

Teaching Your Pet How to be Confined

Tranquility Training Exercises

Using Classical Counterconditioning to Change Emotional State

The password for the site can be found at the following location: second word in the legend to Figure 49.1.

Section I

Aggression

Chapter 1

Aggression: Medical Differentials

Definition/Overview

When an animal exhibits aggressive behavior, the first step should be to rule out any possible medical contribution. Classically, the veterinary profession tends to separate the causes of behavioral changes such as aggression into behavioral and metabolic/organic diseases. This may be inappropriate, since some aggression that is characterized as behavioral in nature may in fact be due to primary organic brain disease that has yet to be characterized, such as abnormalities in serotonin receptors. For the purposes of this chapter, medical causes associated with aggression will encompass those diseases for which we can currently identify an established pathology associated with the disease. Metabolic or organic diseases that may present with aggressive behavior include a vast assortment of disease categories, including degenerative diseases, developmental disorders, endocrine and metabolic diseases, nutritional imbalances, neoplastic disease, neurological disorders, immune-mediated or allergic disease, infectious disease, idiopathic or iatrogenic disease, toxin exposure, traumatic injury, and vascular disorders. The presentation of some diseases may be affected by age (see Table 1.1). Please note that this chapter does not include every possible medical illness that could present with aggression as a complaint.

Table 1.1. Neurological Conditions to Consider for Behavioral Changes, by Age

Medical Considerations for Aggressive Behavior

Degenerative/Developmental

Lissencephaly.

A rare disease that has been described in Lhasa Apsos, Beagles, and Irish Setters, and in cats, in which the gyri and sulci of the cerebral cortex fail to form properly, resulting in a smooth surface.

Behavioral complaints are often apparent by 3 months of age, and can include difficulty in training (especially house training), irritability, aggression, dementia, and depression.

By 1 year of age, most pets suffering from this condition exhibit seizure activity.

Imaging studies can confirm this non-treatable disease.

Hydrocephalus.

Hydrocephalus is usually a congenital problem, but can be acquired secondary to functional CSF obstructions or infectious diseases.

Behaviorally, these pets may present with non-specific clinical signs such as difficult to train, stubborn, demented, aggressive, or irritable, or with seizure activity.

Hydrocephalus may present solely as aggression and irritable behavior in very young dogs.

It is estimated that hydrocephalus accounts for 0.8% of aggressive behaviors.

Signalment can lead a clinician to suspect hydrocephalus, and imaging studies can confirm this diagnosis.

Fucosidosis.

This has been reported in American-bred English Springer Spaniels.

It is a heritable condition involving an alpha-L-fucosidase enzyme deficiency.

Affected animals will experience abnormal accumulation of fucose in cells throughout the body.

Neurological signs predominate, and may include confusion, inability to recognize the owner, and seizures. Fearful behavior can develop into defensive aggression. The disease is progressive and results in death.

Hepatic encephalopathy.

As a result of congenital shunts, enzyme deficiencies, or severe liver disease, animals may show signs of hepatic encephalopathy.

Owners often report periodic behavior changes, including listlessness, depression, pacing, circling, head pressing, hysteria, and viciousness.

The behavioral signs are most evident after a protein-rich meal.

Behavioral changes may be associated with alterations in perception, or due to incoordination.

Feline ischemic encephalopathy.

This unique vascular disorder of the CNS is thought to be related to Cuterebra larva myiasis.

Unilateral cerebral disease is often noted, and signs may include paresis/ataxia, tonic–clonic seizures, blindness, circling toward the side of the lesion, dilated pupils, and severe aggression.

Treatment options are limited, and often cats are euthanized due to the severity of signs.

Porencephaly.

This is cystic malformation of the cerebrum which usually communicates with the subarachnoid space or the lateral ventricle.

It can be congenital or acquired.

Degenerative sensory changes.

Although degenerative sensory changes often occur gradually, and affected animals learn to adjust to them, these changes could potentially cause aggressive behavior.

Visual and auditory deterioration may affect the animal's ability to monitor activity, and therefore they may be startled more easily. Some startled animals react with aggression.

Endocrine/metabolic

Hyperthyroidism.

Although primary hyperthyroidism in dogs is rare, it can present as aggression.

Iatrogenic hyperthyroidism should be considered in irritable or aggressive dogs on supplementation.

Hyperthyroidism in cats is the most common feline endocrine disease, and around 25% of cats with hyperthyroidism present with increased aggression.

Aggression usually resolves with successful treatment.

Hypothyroidism.

Hypothyroidism has been implicated as a cause of many non-specific behavioral signs, such as aggression and anxiety.

Hypothyroidism has been reported to be the underlying problem in 1.7% of dogs with aggressive behavior.

These dogs do not necessarily show the other classical signs of hypothyroidism, such as thin hair coat, lethargy, and weight gain.

The dog acts relatively normally, but will increasingly become grumpy or aggressive in routine situations.

The aggression is inconsistent.

Dogs affected by hypothyroid aggression have been described as dominant aggressive (social conflict aggression) or fear aggressive.

Caution is needed to avoid quickly labeling a pet as hypothyroid instead of delving further into other possible medical or behavioral causes of the presenting problem.

Several recent studies have not shown a statistically significant difference in thyroid status between dogs with and without aggression.

Sex hormones.

From a clinical standpoint, there are sex-linked behaviors that are testosterone driven, such as intermale aggression.

Neutering significantly reduces this aggression in 60–80% of dogs and cats.

Neutering also prevents genetic transmission of this trait.

Pseudocyesis may result in aggressive behavior in the bitch. Hormonal changes may cause behavioral changes typically associated with pregnancy, although the bitch is not pregnant. Nesting, nervousness, mothering of objects, and maternal aggression may be observed. These signs tend to occur about 6–8 weeks after the heat cycle, and will gradually decline as the hormones return to anestrus levels. Ovariohysterectomy in anestrus will prevent relapse.

Spaying bitches before 6 months of age may increase the incidence of inter-dog aggression.

Nutritional

Thiamine deficiency.

This may occur in cats and dogs that are fed predominantly raw tuna, salmon, carp, or other fresh and saltwater fish, due to the presence of thiaminase in these diets.

Sudden and progressive onset of disease occurs, which includes the following: anorexia; diarrhea; muscle tremors; obtunded or excited and aggressive behavior; seizures and other cerebral and vestibular signs.

This nutritional deficiency can cause hemorrhage and necrosis of the brainstem.

Tryptophan deficiency.

Tryptophan is the amino acid precursor of serotonin.

Escalation of aggressive behavior can be a result of this dietary deficiency.

High levels of dietary protein.

High levels (32%) of dietary protein have been incriminated in aggressive behavior in dogs, and specifically in fear-based territorial aggression.

High levels of dietary protein may decrease the amount of tryptophan that is naturally absorbed, causing a deficiency.

To date, definitive studies linking tryptophan, dietary protein, and aggression have not been conducted.

Neoplasia

Neoplasia includes intracranial masses such as meningiomas, temporal lobe, limbic system, and hypothalamic lesions.

Neoplasia, both primary CNS lesions and metastatic lesions, may present as aggressive behavior.

Although most neoplastic lesions that affect the brain will eventually cause some obvious neurological abnormalities, such as seizures or head tilt, it may take up to a year for these to become evident.

Any breed can be susceptible to neoplasia. However, the brachycephalic breeds have a higher incidence of astrocytomas, and the dolichocephalic breeds have a higher incidence of meningiomas.

The temporal lobe, limbic system, amygdala, and hypothalamus are all implicated in the modulation of aggression, and therefore lesions that affect these areas could have an impact on aggressive behavior.

Neurologic

Psychomotor epilepsy.

This behavior can present as aggressive outbursts.

These random, vicious attacks can be difficult to confirm diagnostically.

The syndrome is characterized as having no other behavioral or medical diagnosis, and the pet responds well to antiepileptic drugs.

Immune/allergic

Systemic lupus erythematosus.

This autoimmune disease in dogs may progress to CNS lupus.

Although rarely reported, these dogs may exhibit periodic disorientation and aggression.

Allergic skin disease.

Chronic pruritus can increase irritability in both dogs and cats.

Aggression may result when the animals are handled or groomed, or during treatment of excoriated or infected skin and ears.

Research studies have noted an association between a history of a pruritic or malodorous skin disorder that received veterinary treatment and biting behavior directed toward family members.

Infectious Diseases

These may include viral, fungal, bacterial, protozoal, and rickettsial agents. Infectious diseases usually have an acute onset and may present initially with only behavioral changes, but within hours to days there are usually CNS abnormalities.

Viral.

Dogs: Rabies, pseudorabies, and infectious CDVE.

Rabies: The behavioral manifestations of rabies infection vary widely, and can include disorientation, dementia, aggression, pruritus, coprophagia, pica, excessive sexual behavior, and excessive playfulness. Usually it is a rapidly progressive disease that results in death within 8 days after the first clinical signs.

CDVE: The distemper virus can attack many different body tissues, including the nervous system. Due to the variability of infection sites, clinical signs can be quite variable, but they are usually acute in onset and progressive in nature. Young unvaccinated dogs are most susceptible to this disease. There can be a post-vaccination encephalomyelitis seen 1–2 weeks after vaccination with a modified-live vaccine. Compulsive circling and dementia can be noted with frontal lobe lesions. If the cerebral cortex is involved, seizures are common. Chomping the jaws while staring off into space is a classic sign of distemper encephalitis. Ataxia, paresis, and head tremors are seen with cerebellar involvement. A sensory neuritis may be responsible for the self-mutilation that occurs in some dogs. There is an old-dog form of distemper encephalitis that presents in the older patient as progressive behavioral problems such as circling, dementia, blindness, and pacing.

Cats: Rabies, pseudorabies, feline immunodeficiency virus (FIV), and feline infectious peritonitis (FIP).

Rabies is an example of a viral infectious agent that can present as acute onset of aggressive behavior in cats and dogs.

FIV: This can cause aggressive behavior as well as other non-specific clinical signs, such as dementia and inappropriate elimination.

FIP: The dry form can cause a pyogranulomatous meningoencephalomyelitis and hydrocephalus. The cat may present as demented. It may also have signs of vestibular disease, cerebellar deficits, seizures, and pelvic limb abnormalities. This disease is usually progressive over several weeks or months.

Bacterial.

Bacterial abscesses in the brain tissue are infrequent in small animals, but could present as aggressive behavior.

Usually the dysfunction is slow in onset and progressive.

Clinical signs may start with unilateral visual deficits and then progress to aggression, head tilt, circling, head pressing, mania, depression, convulsions, and coma.

Protozoal infections.

Toxoplasma gondii

This is a common protozoal disease in cats (40% of cats test seropositive), but it can cause infection in most other mammals, including dogs.

Clinical disease is not as common as infection, and the presentation of clinical disease depends on where the organism migrates or localizes.

Although aggression is not a common sign, it is within the realms of possibility, as the site of inflammation could be anywhere in the CNS. This also means that other neurological changes can occur, such as depression, blindness, tremors, seizures, hyperexcitability, and paralysis. Serological testing is recommended to confirm infection if this is suspected.

Neospora caninum.

This can cause CNS and musculoskeletal disease that is similar to toxoplasmosis infection.

Parasitic infections.

Aberrant migration of common parasitic infections can present as acute and progressive aggression.

Cats that present with an acute onset of vicious aggressive behavior may have Cuterebra infarcts.

Other parasites that sometimes migrate into CNS tissue include Dirofilaria, Toxascaris, Ancylostoma, Taenia, and Angiostrongylus.

Idiopathic or Iatrogenic

Granulomatous meningioencephalitis.

This idiopathic, inflammatory proliferation of mononuclear cells in the white matter of the nervous system can occur rarely in cats, but is more commonly seen in dogs such as Poodles and Airedale Terriers.

Behavioral signs depend on the site of these space-occupying lesions, but circling, dementia, compulsive pacing, aggression, and seizures have all been noted with this disease.

Idiopathic feline cerebral infarction.

There is no breed, gender, or age predilection.

Lesions are often confined to the middle cerebral artery, and can result in massive cortical damage.

Neurological clinical signs are often unilateral with hemiparesis.

Resultant seizure and behavioral disorders may be so severe as to make the animal unacceptable as a pet.

Iatrogenic.

Corticosteroids: An adverse drug effect should be considered in cats or dogs that are receiving exogenous steroids and present with aggressive behavior.

Psychotropic medication: Due to serotonin syndrome or bite disinhibition.

Toxins

Lead poisoning.

Inquisitive young animals are considered to be at higher risk for accidental lead ingestion, but any animal with exposure could develop lead poisoning.

Ingestion of lead can cause behavioral changes such as hysteria (including crying, barking, and running and biting at things), dementia, aggression, hyperexcitability, and compulsive pacing.

Gastrointestinal signs often precede behavioral signs.

Zinc phosphide.

In dogs, rodenticide can cause behavioral signs associated with CNS stimulation.

Aimless running, vocalization, snapping, snarling, and seizures are possible presenting signs.

OP/ClHC.

These commonly used insecticides can be implicated in a toxicity that involves behavioral, motor, and muscle abnormalities.

Usually there is a history of contact with the insecticide, and the animal is salivating, has miotic pupils, and has seizures.

ClHC causes a true cerebral encephalopathy.

Aggression is possible as part of the presenting profile.

Methylphenidate or other street drugs.

The animal may present with aggressive behavior.

Trauma

Cranial injury.

Damage to the cerebrum or limbic system from cranial injury may present as aggression.

A history of cranial injury should make this a differential diagnosis.

Pain.

This may result in irritable, defensive, or redirected aggression.

Animals in pain have an activated sympathetic nervous system.

Catecholamine release reduces the aggression threshold, thus making animals in pain more likely to be aggressive.

Vascular

Cerebral vascular disease.

Primary vascular disease (arteriosclerosis) is rare in animals.

Atherosclerosis may result from atherogenic diets; it may be more common in dogs with hypothyroidism.

It may develop as a result of disseminated intravascular coagulopathy, but behavioral signs are likely to be proceeded by systemic changes.

Cerebrovascular accidents may occur due to spontaneous intracranial hemorrhage. Neurological signs are acute, non-progressive, and may be followed by chronic behavioral changes such as aggression.

Cerebral infarcts in cats (see Idiopathic or Iatrogenic above).

Cuterebra larval infarcts (see Infectious Diseases above).

Abbreviations

CDVE = canine distemper viral encephalitis

ClHC = chlorinated hydrocarbon intoxication

CNS = central nervous system

CSF = cerebrospinal fluid

FIP = feline infectious peritonitis

FIV = feline immunodeficiency virus

OP = organophosphate

Suggested Reading

Aronson, L. P. 1998. Systemic causes of aggression and their treatment. In: Dodman, N. H. and L. Shuster (eds), Psychopharmacology of Animal Behavior Disorders. Blackwell Science: Malden, MA. 64–102.

Fatjo, J. and J. Bowen. (2009) Medical and metabolic influences on behavioural disorders. In: Horwitz, D. F. and D. S. Mills (eds), BSAVA Manual of Canine and Feline Behavioural Medicine, 2nd edition. British Small Animal Veterinary Association: Gloucester. 1–9.

Overall, K. L. 2003. Medical differentials with potential behavioral manifestations. Veterinary Clinics of North America: Small Animal Practice 33:213–229.

Tilley, L. P. and F. W. K. Smith, Jr. (eds). 2016. Blackwell's Five-Minute Veterinary Consult: Canine and Feline, 6th edition. John Wiley & Sons Inc.: Ames, IA.

Author: Amy L. Pike

Part I

Canine Aggression

Chapter 2

Aggression/Canine: Classification, Overview, and Prognosis

Definition/Overview

Aggression may be defined as an action that functions to threaten or harm its recipient. There are many ways to classify aggressive behavior. One useful classification considers aggression to be either offensive or defensive. Offensive aggression is an assertive action that is initiated to achieve a goal. For example, aggression may be initiated in an attempt to gain access to a resource such as food, a valuable resting place, or a mate, or in a contest over dominance or status. Defensive aggression is aggressive behavior exhibited in response to aggression initiated by others. The threat may be genuine, such that a trigger is apparent. Alternatively, there may be no clear trigger. Previous experience, behavioral pathology, and medical pathology can contribute to a patient's perception of threats. Dogs that have experienced pain or profound fear, that have anxiety-based conditions, or that have been unsuccessful in maintaining access to resources in previous conflicts may react aggressively in anticipation of a potential threat. Their aggressive response may appear offensive and unprovoked as the threat is not readily apparent.

Aggression may also be classified based on the context or stimuli that trigger the aggressive response. Examples include fear-induced, irritable, territorial, maternal, learned, and male-to-male aggression.

When evaluating clinical patients, if the physiological or neurochemical basis for aggressive behavior cannot be determined and the motivation is not clear, it can be helpful to use descriptive terminology for the purpose of communication. For instance, a dog may be described as exhibiting aggression toward strangers, toward familiar people, or toward other dogs, at home or away from home.

Etiology/Pathophysiology

Communication through aggressive posturing is considered to be part of the normal canine social behavioral repertoire.

Aggression may be abnormal and represent behavioral pathology or an underlying anomaly in the dog's neurological function.

It is difficult to confirm the pathology or specific etiology in individual patients, as diagnostic tests to evaluate neurotransmitter levels are not commercially available at the time of writing.

Reduced serotonin levels in the CNS may be associated with aggressive behavior.

Areas of the brain involved in aggression include the hypothalamus, the limbic system, and the frontal cortex.

Aggression is affected by both genetics and experience.

Signalment/History

Dogs of any age, gender, or breed can exhibit aggressive behavior.

Dogs commonly present between 6 months and 2 years of age. Note that age of presentation is not the same as age of onset, as the behavior may have been present for several months before the owner seeks assistance. Sudden onset of aggression in mature dogs may reflect an underlying medical disease. Cognitive decline should be considered in dogs aged 8 years or older.

There may be an increased tendency for male dogs—whether intact or neutered—to exhibit aggressive behavior.

A predisposition to exhibit territorial behavior toward intruders may be present in breeds that have been purposely bred for guarding and protection, such as German Shepherds, Rottweilers, Dobermans, and Mastiffs.

It is critically important to evaluate each dog as an individual, rather than rely on breed standards or tendencies. Any breed can exhibit aggressive behavior.

An individual dog's present and past health, nutrition, handling, socialization, training, and experiences may be more relevant to the development of aggressive behavior than is the breed.

Historical Findings

Normal aggressive behavior typically includes initial low-level signaling that intensifies as the threat persists or escalates. Triggers can be identified, and the aggressive response is in proportion to the perceived threat.

Aggressive behavior is considered abnormal when responses are out of proportion to the threat, when aggression occurs in the absence of any clear trigger, and/or when the aggressive response is not inhibited, particularly in the absence of low-level aggressive threats. Rapid escalation to biting, and biting that continues even as the threat is withdrawn, indicate abnormal aggression.

Dogs that exhibit unpredictable and/or uninhibited aggression are difficult to treat and can present a significant risk to others.

Contributing/Risk Factors

This list is not exhaustive; see the relevant chapters for risk factors associated with a specific type of aggression.

The manifestation of aggression may be influenced by underlying medical conditions, early experiences (successful use of aggression to maintain access to resources and/or reduce fear), and genetics.

Contributory medical conditions must be ruled out, since illness and/or pain may increase aggressive behavior.

Previous use of extreme or inconsistent punishment may contribute to a more intense aggressive response.

The use of inconsistent and inappropriate punishment, particularly when expectations are unclear, can contribute to anxiety and aggression.

Inadequate early socialization.

Unsupervised interactions with young children.

Unsupervised opportunities to bark at passing people and dogs, particularly if the dog is tethered or contained only by an underground fencing system.

Traumatic experience(s).

Pertinent Historical Questions

In every case of aggression it is important to assess the risk of keeping the dog in the home. A behavioral baseline should include all of the following information:

What is the household composition, including family members and other pets?

This information enables the clinician to identify areas that need additional management to ensure safety. In large complex households it may be more difficult to maintain safety, and time devoted to behavioral therapy may be more limited.

A mechanism must be in place to rigidly maintain safety rules when elderly or infirm individuals and/or young children are present in the home.

Other pets must also be protected. This may require a means of separating them from the aggressor when a responsible household adult is not available to supervise the animals.

What is the pet's typical daily routine, including feeding, training, exercise, and play?

Treatment and safety recommendations will need to be incorporated into an acceptable household routine.

Does the dog have free access to food and toys, and if so, can these be managed if necessary?

How much time is spent training the dog each day? Training improves communication and teaches the dog about its owner's expectations.

Interactive play and exercise reflect owner commitment.

Dogs contained by underground fencing systems require supervision when outside.

Safety may be compromised by the use of extendable leads.

The use of collars that inflict pain or discomfort, such as pinch collars and electronic collars, may inadvertently increase fear and/or aggression.

In general, the more stable and predictable the environment, the better the prognosis for reducing aggressive behavior.

Households with frequent visitors may find management challenging.

What are the owner's expectations of the dog?

Dogs that have exhibited aggressive behavior need to be supervised and physically controlled by an adult owner at all times.

Dogs that have exhibited aggression toward strangers or non-household dogs may never improve enough to be walked off leash in public areas or taken to an outdoor gathering.

Ask the owner to describe several representative episodes, including the age of the dog at the time, the context, the target, the dog's posture, and the owner's response. (See the Ladder of Aggression in Appendix C on the companion website at www.fiveminutevet.com/behavior.)

Punishment may exacerbate aggression.

Patients that show rapid escalation of aggression in the absence of inappropriate interventions may have more serious behavioral disorders.

Sudden onset of behaviors in the absence of environmental changes may reflect underlying physical disease.

Is the aggression predictable in terms of when it will occur, where it will occur, or toward whom?

Dogs that do not signal prior to biting, or dogs that bite in the absence of a clear trigger, are difficult to manage.

Bear in mind that owners may not always identify triggers, and may not be able to recognize low-level threats. Video recording of aggressive episodes can be helpful. However, at no time should the owner attempt to elicit aggression in order to obtain a video recording.

Have there been actual bites, and if so, how severe were the injuries?

The long-term prognosis may be poor in dogs that have inflicted serious bites, and in dogs that have inflicted multiple bites during a single event.

Differential Diagnosis

Underlying medical conditions can contribute to or cause aggression. Examples of medical conditions that should be considered prior to establishing a primary behavioral diagnosis include the following:

Developmental abnormalities (hydrocephaly, lissencephaly, hepatic shunts).

Metabolic disorders (hypoglycemia, hepatic encephalopathy, diabetes).

Endocrinopathies (hypothyroidism, hyperadrenocorticism).

Neurological disease (intracranial neoplasm, seizures, encephalopathy, encephalitis, CNS infection or inflammation).

Toxins.

Rabies.

Pain.

Terminology in behavioral medicine is continuing to evolve. The following is a list of common diagnostic terms.

Note: These labels consider only the presumptive underlying motivation and the phenotypic description of the aggression. At the time of writing, research is ongoing but it is not yet possible to establish a clinical behavioral diagnosis based on a patient's biochemical or molecular abnormalities.

Anxiety- and fear-based aggression.

Food-related aggression.

Idiopathic aggression.

Interdog aggression.

Maternal aggression.

Pain-related and irritable aggression.

Play-related aggression.

Possessive and resource-guarding aggression.

Predatory behavior.

Redirected and excitement-related aggression.

Social conflict-related aggression.

Territorial and protective aggression.

Diagnostics

A complete physical examination and neurological examination should be conducted.

Further diagnostic testing is based on the physical examination findings. A minimum database should include CBC, chemistry profile, endocrine testing, and urinalysis.

An underlying medical condition should be strongly suspected in any patient that presents with a history of acute onset of aggression, or in middle-aged or senior dogs with no previous history of aggression. Consider toxin exposure, metabolic disease, infection, and neurological disease with associated cognitive or sensory deficits.

Therapeutics

Therapy will be dependent upon the type(s) of aggression diagnosed. In all cases, safety is a primary concern and risk assessment should be performed. The first tenet of management is to prevent human injury and establishing safety precautions.

Help the owner to understand the specific risks involved in treating and managing their dog. It must be explained to the owner that a complete cure is unlikely, but that treatment can reduce the frequency and intensity of aggression in many patients. Some management steps and safety guidelines will need to be maintained for the rest of the dog's life.

If safety cannot be ensured and rehoming would not be safe or feasible, an evaluation by a veterinary behaviorist should be recommended, as euthanasia is the only way to prevent future injury with certainty.

Management should be designed to prevent injury to others. A management plan may include the use of gates, leash restraint, head collars, and muzzles (Fig. 2.1).

Basket muzzles reduce the risk of injury, but should only be used under direct supervision. A muzzled dog must not be provoked.

Children must be supervised at all times when the dog is present.

Avoid situations that are known to trigger the unwanted behavior, except during controlled treatment sessions when the stimulus intensity can be minimized and the target of aggression kept safe.

Behavior modification should be designed to reduce the dog's reaction to specific triggers.

Behavioral Modification Techniques

Punishment (verbal reprimands, leash corrections, or physical reprimands) should not be used to treat aggression. Punishment might suppress outward expressions of aggression, but underlying emotional affect, such as fear and anxiety, remains and may intensify.

For most cases of aggression it is appropriate to institute reward based and non confrontational methods of communication. This helps to create a predictable basis for interaction, and uses cues to help the owner and the dog to communicate. Often this begins by utilizing simple requests such as Sit, Wait or Watch me to give more control and predictability to daily situations. (For further details, see the Structuring Your Relationship with Your Pet handout in Appendix D on the companion website at www.fiveminutevet.com/behavior.)

In most cases of aggression, a desensitization and counterconditioning program is instituted with regard to the specific triggers for the aggression.

Fig. 2.1. Dog wearing a soft nylon basket muzzle (Proguard Softie Muzzle™). There is a tough mesh screen at the front to allow airflow, so the dog can open its mouth and pant, but the bite is inhibited.

Accompanying Handouts

Acute Management of Problem Behavior

Assessing Prognosis in Aggressive Dogs

Basic Principles for Children and Dogs

Basic Principles for Introducing Pets to a New Baby

Canine Body Language

Desensitization and Counterconditioning: The Details

Go to Place

How to Reduce Food-Guarding Behavior in Dogs

Markers and Reinforcers

Maximizing Treatment Success

Muzzle Training: Training Your Dog to be Comfortable Being Muzzled

Safety Recommendations for Aggressive Animals

Structuring Your Relationship with Your Pet

Target Training

Teaching Your Pet How to be Confined

Tranquility Training Exercises

See the handouts in Appendix D on the companion website at www.fiveminutevet.com/behavior.

Drugs (see Appendix A)

The clinician must advise the owner that the use of psychotropic medication to treat canine aggression is off-label. Because of liability concerns, it is advisable to make a note in the patient record stating that the owner was informed of the potential risks and side effects. Signed informed consent forms should be obtained. Before prescribing medication, make sure that the owner understands the risks involved in owning a dog that exhibits aggressive behavior, and that they must follow safety procedures and not rely on medication to keep others safe.

Never use medications without behavior modification.

See the relevant chapters on specific forms of aggression for detailed recommendations.

Contraindications/Precautions

Most medications that are used to treat canine and feline behavioral conditions are not FDA approved for this use. Therefore the clinician should advise the owner of any use of off-label medication, and document this communication.

Prior to medicating a pet, the animal should be examined and laboratory screenings conducted to evaluate the ability of the pet to metabolize and excrete the medication adequately. A minimum database should include CBC, chemistry panel, urinalysis and thyroid evaluation.

Transdermal doses have not been established, and poor absorption is a concern.

Use of TCAs such as amitriptyline or clomipramine in patients with cardiac abnormalities, seizures, or glaucoma should be avoided if possible, or only undertaken with extreme caution, as these drugs may potentiate pre-existing cardiac conduction problems.

Paradoxical reactions to and unacceptable side effects of the medications are possible. Side effects can include increased anxiety or aggression. The pet's response to therapy should be monitored, and treatment modified or discontinued when indicated.

Serotonin-enhancing medications should be used with caution or avoided in animals that suffer from epileptiform seizures, as these drugs may aggravate the seizures.

Due to the potential for serious side effects, including fatal serotonin syndrome, concomitant use of multiple serotonin-enhancing medications should be undertaken with caution. This includes concurrent use with other SSRIs or TCAs, as well as MAO inhibitors (e.g., amitraz, selegiline) and tramadol.

TCA overdoses can cause profound cardiac conduction disturbances that lead to death. Therefore all medications should be stored and managed carefully.

Use caution when prescribing benzodiazepines for animals that are exhibiting any level of aggression, as these drugs may disinhibit aggression if they reduce fear-based inhibition of biting.

About 10% of animals exhibit a paradoxical reaction to benzodiazepines, and become anxious and agitated instead of calm and relaxed.

Diazepam-induced hepatotoxicity has been reported in some cats after oral administration. Therefore this drug and other benzodiazepines should be used with caution in cats.

Benzodiazepines are lipophilic, and their effects may be potentiated by other lipophilic drugs. If combination treatment is warranted, use lower dosages.

Benzodiazepines are a controlled substance and pose a risk of human abuse.

Use caution when prescribing alpha-2-adrenergic receptor agonists (e.g., clonidine) for patients with hypertension or cardiac disease, and in combination with drugs that increase norepinephrine levels.

Caution is advised when using psychotropic medications in conjunction with other CNS-active drugs, including general anesthestic, neuroleptic, anticholinergic, and sympathomimetic drugs.

Medications that are given for any substantial period of time should ideally be tapered down in dose rather than abruptly withdrawn.

For pets that are on long-term medication, an annual or semi-annual recheck (including physical examination, CBC, and chemistry panel) is recommended.

Consult individual drug monographs for complete lists of contraindications and precautions.

Other Treatments

If anxiety is a suspected component, a pheromone product (e.g., Adaptil® dog-appeasing pheromone) in a plug-in diffuser formulation may be prescribed.

Nutraceuticals (e.g., Anxitane®, Zylkene®) can potentially decrease stress and anxiety that may underlie aggressive behavior in some patients. The active ingredient of Anxitane® is L-theanine, which has a calming effect on pets by enhancing the action of the inhibitory neurotransmitter GABA in the brain. The active ingredient of Zylkene® is alpha-casozepine, which affects the opioid system, as well as potentially increasing brain GABA activity.

Diet

Low-protein/high-tryptophan diets may help to reduce aggression in some patients, but are unlikely to make a significant difference without behavior modification.

Surgical Considerations

Intact male animals should be neutered.

This may or may not decrease the intensity or frequency of aggressive episodes, but does prevent possible genetic transmission.

Female animals that start to show aggression toward familiar people when less than 6 months of age may be less aggressive when mature if spaying is delayed.

Comments

Client Education

Client education is paramount, to ensure that the owner understands the limitations of treatment and also their duty to protect others.

Aggression cannot usually be cured. At best, treatment will reduce the likelihood that the dog will respond with aggression in certain situations.

Patient Monitoring

Owners often require ongoing assistance with behavior cases, especially those involving aggression. It is advisable to make at least one follow-up call within the first 1–3 weeks after the consultation. Provision for further follow-up either by phone or in person should be made at that time.

Weekly or bimonthly updates over the course of several months are recommended.

Prevention/Avoidance

Provide preadoption counseling to help owners to select a breed that suits their temperament and lifestyle.

Obtain behavioral baselines during well-care visits, in order to identify aggression early.

Ensure that puppies receive adequate socialization. Young puppies need to be socialized even though they have not yet completed their complete vaccination series. This is because by 12 weeks of age the sensitive period for socialization is nearly over.

Help owners to create a predictable environment for their dog by using reward-based training methods.

Possible Complications

Injuries to people or to other pets.

Changes in household routine or composition (e.g., a new baby, a new pet) may affect the family's ability to follow safety recommendations.

Expected Course and Prognosis

Aggression cannot usually be cured. The prognosis for improvement is better if the aggression is of low intensity, occurs in a relatively small number of predictable situations, and has been present for only a short time.

The overall prognosis is highly dependent on owner compliance and their ability to work with and control the dog.

Behavior does not typically change rapidly. A rapid initial reduction in aggression must be achieved through management. The gradual reduction in aggressive responses to selected triggers may occur over a period of months rather than days.

See Also

Chapter 1, Aggression: Medical Differentials

Chapter 3, Aggression/Canine: Fear Based or Defensive

Chapter 4, Aggression/Canine: Food

Chapter 5, Aggression/Canine: Human Directed/Familiar People

Chapter 6, Aggression/Canine: Human Directed/Unfamiliar People

Chapter 7, Aggression/Canine: Idiopathic

Chapter 8, Aggression/Canine: Interdog/Familiar Dogs

Chapter 9, Aggression/Canine: Interdog/Unfamiliar Dogs

Chapter 10, Aggression/Canine: Possessive/Resource Guarding

Chapter 11, Aggression/Canine: Redirected

Chapter 12, Aggression/Canine: Territorial

Chapter 13, Aggression/Canine: Veterinary Office

Abbreviations

CBC = complete blood count

CNS = central nervous system

FDA = Food and Drug Administration

GABA = gamma-aminobutyric acid

MAO = monoamine oxidase

SSRI = selective serotonin reuptake inhibitor

TCA = tricyclic antidepressant

Suggested Reading

Casey, R., B. Loftus, C. Bolster, G. Richards, and E. Blackwell. 2014. Human directed aggression in domestic dogs (Canis familiaris): occurrence in different contexts and risk factors. Applied Animal Behavior Science 152:52–63.

Overall, K. L. 2013. Abnormal canine behaviors and behavioral pathologies involving aggression. In: Manual of Clinical Behavioral Medicine for Dogs and Cats. Mosby: St. Louis, MO. 172–230.

Reisner, I. 2002. An overview of aggression. In: Horwitz, D. F., D. S. Mills, and S. Heath (eds), BSAVA Manual of Canine and Feline Behavioural Medicine. British Small Animal Veterinary Association: Gloucester. 181–194.

Sueda, K. and R. Malamed. 2014. Canine aggression toward people: a guide for practitioners. Veterinary Clinics of North America: Small Animal Practice 44:599–628.

Author: Ellen M. Lindell

Chapter 3

Aggression/Canine: Fear Based or Defensive

Definition/Overview

Canine fear-based or defensive aggression is an aggressive response that is intended to increase the distance between the dog and a perceived threat. Not all fearful behavior that is exhibited by dogs is maladaptive or abnormal. A threat may be legitimate. Behavioral signs initially include fearful body postures and signs of sympathetic stimulation (e.g., tachypnea, tachycardia). Examination of body posture alone is not reliable, as posture may change with experience. Anxiety about social situations, places, or things may underlie fear-based aggression.

Etiology/Pathophysiology

Early traumatic experiences and inadequate socialization of puppies during the sensitive socialization period may contribute to the expression of fearful responses toward people and other dogs.

Pre- and perinatal factors, including maternal health, diet, and behavior, may contribute to the behavior.

Genetic factors may possibly be involved, but remain underexplored and have rarely been documented. Strains of nervous Pointers have been identified, and the condition appears to be heritable.

Fear may trigger catecholamine release with subsequent increases in heart rate, respiration rate, and pupillary dilatation, and decreased pain sensitivity.

Signalment/History

There is no gender predilection, and the behavior is not affected by neutering.

Some breeds, such as German Shepherds, appear to be predisposed to fear-based or defensive aggression.

This behavior can occur at any age. Subtle signs may appear in young puppies. Intensification of the behavior often occurs at 6–9 months, along with the appearance of readily recognized fear-based or aggressive postures.

Historical Findings

Aggressive responses may occur along a continuum from mild growling or snarling to lunging and injurious bites. Responses may appear disproportionate to the suspected level of provocation.

Aggression is initially accompanied by fearful or submissive body postures and facial expression (low posture, ears flattened back against the head, tail tucked, and averted gaze). Body posture may change over time from submissive to assertive as the animal learns that aggressive responses are effective in warding off threats. The intensity of the behavior may also increase from growling and snarling to lunging and biting.

The history may include a previous painful or fear-inducing experience in a similar situation (e.g., veterinary visit, visit to groomer).

Aggression may be directed toward familiar and unfamiliar people and/or dogs.

Aggression often increases in intensity when the dog is cornered or cannot escape.

Sudden movement, a rapid approach, a retreat, or reaching toward the dog may elicit an aggressive response.

The dog may appear to tolerate proximity to a person, but may growl and snap as the person withdraws their hand or turns to leave.

Aggressive behavior may occur as a component of territorial, possessive, and owner-directed aggression.

Triggers may be very specific (e.g., men wearing hats, children on bicycles, attempts to take items from the dog) or more general (e.g., all people wearing hats, all men, all strangers).

Some dogs exhibit anxiety in one or more other contexts (e.g., owner's departure, thunderstorms, car journeys).

Contributing/Risk Factors

Fear-based aggression can be a normal canine response in certain circumstances.

Inadequate early socialization, early painful or serious illness, exposure to confrontational training methods, and inappropriate punishment may contribute to the development of fear-based aggression.

Puppies that have been appropriately reared with no known trauma may nevertheless develop fear-based aggression as they mature.

Punishment during aggressive episodes can unintentionally increase fear-based aggression and underlying anxiety.

Previous use of extreme or inconsistent punishment may contribute to a more intense aggressive response.

Traumatic experiences may predispose certain dogs to the development of fear-based aggression.

Concurrent medical conditions that increase pain and irritability, including but not limited to dermatological disease, musculoskeletal problems, chronic gastrointestinal problems, and metabolic or endocrine dysfunction, may increase the risk of an aggressive response to a threat.

Pertinent Historical Questions

What is the household composition, including family members and other pets?

This information enables the clinician to identify areas in which management, particularly safety guidelines, might be difficult to enforce. Young children or infirm adults, as well as other household pets, may be at risk of accidental injury if the patient is easily emotionally aroused.

What is the pet's typical daily exercise routine?

Dogs contained by underground fencing systems require supervision.

Dogs should always be walked by responsible adults using a secure leash.

Ask the owner to describe the onset, duration, and progression of the problem behavior.

Progression from early signs of fear (e.g., retreating while barking, hiding) to assertive and apparently confident behavior over time supports the diagnosis.

Fear-based aggression in young puppies may reflect underlying behavioral pathology or inadequate early socialization.

Rapidly escalating aggression may reflect serious behavioral pathology.

Ask the owner to describe several representative episodes, including the age of the dog at the time, the context, the dog's posture and facial expressions, and the owner's response. Descriptions should be objective (i.e., what the dog did, not what the owner thought the dog meant).

Ask them to describe the first episode of any aggressive or fear-based response toward a person.

Ask them to describe the most recent episode.

Create a timeline including a description of two or three representative episodes. Include significant environmental changes or medical events. This information can help the clinician to determine the rate of progression and assess any learned component.

Patients that escalate quickly in the absence of inappropriate interventions may have more serious behavioral disorders.

Sudden onset of behaviors in the absence of environmental changes may reflect underlying physical disease.

Include a description of the dog's behavior after an incident. Slow recovery may be due to a continued increased level of arousal, the perception that the threat is continuing, or other underlying anxiety disorders.

Assess the severity of episodes. (See the Assessing Prognosis in Aggressive Dogs handout in Appendix D on the companion website at www.fiveminutevet.com/behavior.)

Identify trigger stimuli. Details should include the distance, the behavior of the trigger person, and other salient features (e.g., speed, location).

What is the frequency of the behavior? For what percentage of the time does the behavior occur when the dog encounters a trigger?

A high frequency of episodes may make management more challenging.

A low frequency of episodes can make the behavior less predictable.

Video recording can be used to help to evaluate body posture and facial expressions before, during, and after the episodes. However, at no time should the owner attempt to elicit aggression in order to obtain a video recording.

Fear-based body posture is generally low, with tucked tail, and ears flattened back against the head. The pupils are dilated. Piloerection may be noted. Rapid high-pitched barking is common, and growling or snarling may occur.

Body posture may vary over time in different contexts and situations. As the intensity of fear increases, the dog may prick its ears forward and may lunge forward.

Ascertain what previous treatments have been used, including those that were helpful, those that made the condition worse, and those that had no apparent effect. There is no need to repeat treatments that were not successful unless they were incorrectly administered.

Differential Diagnosis

Social conflict-related aggression toward familiar people.

Territorial aggression.

Protective aggression.

Learned aggression.

Pain-related aggression.

Possessive/resource-guarding aggression.

Sensory deficit.

Pathological disease conditions associated with aggression.

Other anxiety-based conditions.

Diagnostics

A complete physical examination and neurological examination should be conducted.

Further diagnostic testing is based on the physical examination findings. A minimum database should include CBC, chemistry profile, endocrine testing, and urinalysis.

Therapeutics

Safety Precautions

Prevention of human injuries must be the first priority.

The dog must be restrained by a leash and/or muzzled in the presence of people who have triggered fear-based aggression in the past. If restraint is not possible or safe, the dog should be confined out of the area. A leash and/or muzzle should be used in public locations and when there are visitors to the home.

Dogs contained within an underground fence should be directly supervised and perhaps on a leash held by an adult.

Contexts in which aggression has been triggered must be identified and avoided until treatment has been completed.

The aim of treatment is to control the problem, not to achieve a cure. Management may need to be lifelong.

The owner must be made aware that there will always be a risk of the dog biting.

Some dogs, particularly small dogs with a low level of fear or aggression, can be successfully rehomed. Safety and liability concerns must be discussed.

Inform the owner that they are responsible for following all safety guidelines and taking on the risks of living with an aggressive dog in their home. In serious cases, when safety cannot be ensured and rehoming would not be safe or feasible, an evaluation by a veterinary behaviorist should be recommended. In some situations, euthanasia may be the only way to prevent future injury.

All members of the household must comply with treatment recommendations.

Management Techniques

Introduce a method of secure confinement, such as a crate, baby gate, or a quiet room. (See the Teaching Your Pet How to be Confined handout in Appendix D on the companion website at www.fiveminutevet.com/behavior.)

Head collars may provide increased control during leash restraint.

Basket muzzles reduce the risk of injury, but should only be used under direct supervision. A muzzled dog must not be provoked.

Avoid situations that are known to trigger the unwanted behavior, except during controlled treatment sessions when the stimulus intensity can be minimized and the target of aggression kept safe.

Behavioral Modification Techniques

Use reward-based, non-confrontational methods to teach the dog cues that will allow household members to maintain calm control and improve communication.

Frequent use of simple cues in non-threatening contexts promotes the dog's ability to respond positively to communication from its owner, and encourages the animal to comply with directions. For example, compliance with Sit provides access to a reward (not just food rewards, but privileges such as going outdoors, petting, etc.).

Sample cues include Watch the owner when asked, Turn away from a trigger, Walk beside the owner, and Sit stay quietly.

Relaxation exercises such as sit stay exercises or settling on a leash beside a person will reduce arousal levels and help the dog to tolerate leash restraint in the presence of strangers. (See the Tranquility Training Exercises handout in Appendix D on the companion website at www.fiveminutevet.com/behavior.)

Teach family members to communicate their intent before and during interactions with the dog, so as to create safer and predictable interactions with the pet.

Teach the dog cues to signal the beginning of an interaction. Calmly call the dog and announce your intent (e.g., Play time, Brush time, Walk time).

For dogs that have exhibited aggression during manipulation, use a relaxation cue (e.g., Good stay, Good relax) during the interaction, and limit the duration of the interaction to prevent a fear or aggressive response. (See the Tranquility Training Exercises handout in Appendix D on the companion website at www.fiveminutevet.com/behavior.)

End the interaction with a cue such as All done or Go to bed.

Ask the dog to respond to a known cue, such as Sit, before it is given access to rewards or privileges.

Desensitize the dog to triggers that cannot be avoided or that the owners would prefer not to avoid.

Teach cues that will allow family members to remove the dog from provocative contexts verbally rather than physically (e.g., Go to bed).

Use counterconditioning and desensitization (CCDS) to address specific fear- and aggression-provoking stimuli.

Establish a stimulus gradient from the stimuli that are least likely to cause the fearful