Canine Aggression toward Humans
World Small Animal Veterinary Association World Congress Proceedings, 2004
Moisés Heiblum
Veterinary Hospital Universidad Nacional Autfinoma de México, University of Mexico
Mexico City, Mexico

Aggression is one of the most frequent behavioral problems in dogs; it is a very important public health issue. It is important to keep in mind that any dog can be "potentially" dangerous regardless of breed, environment and learning play a very important role in the development of aggression in dogs, as well as the sociology of the people wanting aggressive animals also plays a major role in the development of the problem.

General information protocol

 Aggression is a symptom not a diagnosis

 Can not be cured

 Could have many causes

 Prognosis and treatment are different depending on the type of aggression displayed

Owner directed aggression

 Persistent aggression, biting, snapping, growling toward family members

 Mostly in competitive contexts

 Showing dominant or offensive postures

 Generally manifested in a predictable way

 Owner directed aggression can occur together with other problems that make its diagnosis and treatment more difficult

 Impulsivity and anxiety

 Impulsivity means a reduction or a complete lack of warning signals prior to an attack

 Impulsivity makes the dog more dangerous and complicates diagnosis, especially because it is difficult for the owners to link the occurrence of aggression episodes to specific situations.


 Anxiety postures and typical postures of fear aggression are showed during aggression episodes

 Hierarchic conflicts between dogs are quickly resolved and the resulting hierarchy tends to be very stable

 However, in the domestic environment owners sometimes behave towards the dog as dominant individuals whereas in other situations they adopt a submissive posture

 Aggressive behavior is explained as a defensive behavior in front of and unpleasant situation

 Case Report: "Dios" Owner directed aggression


 Intact male

 Pit bull terrier

 7 years old

Chief complaint

 Aggression towards the male owner


 Glicinia (female owner)

 Mardo (male owner)

 Lola (kitten)

 2 male adult dogs in another yard

 Maid 2x a week

 Occasionally Glicinia's sister and two kids (Glicinia's nieces)

Onset of behaviors

 Aggressive behavior was first noticed when Dios was about 2 years old

 To Mardo when tried to get Dios off the bed when Glicinia was already in

 When Mardo approached Glicinia during her menstrual period

 Both incidents were without biting

First biting incident 4 years ago: Glicinia and Dios were in bed, Mardo tried to move Dios to get closer to her and Dios bit him in the hand. Glicinia was able to get Dios off and calm him down.

Most recent biting incident 3 weeks prior to consultation. Glicinia was working at her desk, Dios was sleeping by her side, Mardo approached her and Dios bit him in the ankle, owner reported no warning signals before the bite.

Since the last incident Mardo is afraid of Dios and has stopped all interaction with him, Glicinia reinforces Dios all attention and affection demands, in the house Dios is very sociable and demands attention from anybody including visitors, he shows hyper-attachment behavior towards Glicinia whom reports also signs of separation anxiety when she is not home or does not pay attention to him (scratching doors, chewing, urinating in the house and barking).

Medical History


 Vasectomized at 6 years old


 Hand signals training: Go, sit, stay, down, come

 Using food rewards and petting

Diagnostic Plan

General exam

 Basic neurological exam

 Thyroid Panel

 Routine hematology and biochemistry profile


No remarkable findings

Behavioral Diagnosis

 Competitive aggression towards the male owner

 Protective aggression of the female owner

 Anxiety related aggression

Other related diagnosis during clinical history

 Hyper-attachment to female owner with signs of separation anxiety

 Generalized anxiety probably due to deafness and inconsistent handling

Goals for the treatment plan

 Provide safety and confidence to the owners in every day life

 Establish a proper social relationship between dog and owners

 Create a reliable and consistent lifestyle for Dios

 Have more obedience control with hand signals commands

 Work on the hyper attachment behavior

Treatment Plan


 Avoid situations in which Dios is able to display aggression, or situations where Dios has shown aggression before

 No punishment, No confrontation

 Provide a consistent and predictable lifestyle for Dios

 Use of a Gentle Leader® and indoor remote control leash

 Increase exercise and create routines

 Avoid letting Dios to sleep or rest at valuable places such as bed, sofa or door entrances

 Practice obedience commands with hand signals using food as a reinforcer, particularly the male owner

 Affection/Food control program (NILIF) Using obedience hand signals commands and calm behaviors in order to get anything Dios wants

 Lower Social interaction with female owner

 Avoid any kind of competitive play

 Ignore all attention demands initiated by Dios

 Reward independent, calm and submissive behaviors

 DS & CC to departures using graduated planned departures with a safety cue

 Fluoxetine 30 mg every 24h PO


1.  Askew HR. Treatment of behavior problems in dogs and cats: A guide for the small animal veterinarian: Iowa State; 1998

2.  Beaver B. Dog bite prevention, Proceedings of the 138 Th AVMA convention; July 2001 Boston, MA

3.  Fogle B. l The dog's mind: Understanding your dog's behavior: Howell Bookhouse; 1990

4.  Manteca X. Difficulties in the diagnosis of dominance aggression in dogs, Proceedings of the 27th. WSAVA congress

5.  Overall K. Clinical behavioral medicine for small animals: Mosby; 1997

6.  Simpson B. Update on behavioral drugs, Proceedings of the 138 Th AVMA convention-2001 Boston, MA

Speaker Information
(click the speaker's name to view other papers and abstracts submitted by this speaker)

Mois├ęs Heiblum, Professor of Behavioral Medicine
University of Mexico
Mexico City, Mexico

MAIN : Behavior : Canine Aggression
Powered By VIN