CVC Virginia Beach 2017: Fear-Based Aggression in Dogs

At the 2017 Central Veterinary Conference in Virginia Beach, Virginia, veterinary behaviorist John Ciribassi, DVM, DACVB, discussed fear-based aggression in dogs. Dr. Ciribassi described body postures associated with fear-based aggression, when this type of aggression is most likely to occur, and appropriate management options.

Dr. Ciribassi stated that canine aggression is not necessarily problematic. Aggressive behaviors in dogs, he said, are normal tools for self-defense, acquiring food, defending resources, and establishing a pack structure.

If an owner comes in with an aggressive dog, though, it’s important to remember that “aggressive behaviors are not pictures, they’re movies,” Dr. Ciribassi advised. In other words, the aggression, rather than being static, has progressed over time.

Recognizing Fear in Dogs

To diagnose fear-based aggression, it is important to evaluate the overall history, determine when the aggression occurs, and observe the dog’s body postures during threatening situations. Dr. Ciribassi cautioned against assuming that a fearful dog has a history of being abused.

In a threatening situation, a fearful dog will initially display defensive behaviors:

• Ears back
• Tail tucked
• Averted gaze
• Head down
• Weight shifted backward
• Lips retracted to expose all teeth
• Urinating, defecating, expressing anal sacs

If these postures and behaviors don’t ameliorate the situation, the dog will escalate its behavior and become aggressive—often explosively—to manage the threat. If the aggressive behavior manages the threat effectively, the dog will learn to use it more efficiently and as a first resort in other threatening situations.

Dr. Ciribassi also described dominance-based aggression, given that many cases of fear-based aggression are misdiagnosed as dominance-based, leading to aversive-type treatment methods that actually worsen a dog’s fear.

Dominant behavior, characterized by confident body postures and ritualistic displays, usually begins at social maturity and is used to establish a hierarchy. Interestingly, dogs may progress from defensive to dominant body postures if they learn how to use aggression to manage a situation successfully; the defensive postures can return, though, in overwhelmingly threatening situations.

Fear-based Aggression Situations

Fear-based aggression commonly occurs during leash walks. The leash can transmit the owner’s anxiety and make it difficult for dogs to display typical aggressive behavior. Fearful dogs on the leash may display aggression as an unfamiliar person or dog is walking away.

Fear can also result from an owner trying to establish dominance over the dog, using strong physical or verbal punishment, or having inconsistent interactions with the dog. In turn, the dog may become fearful of the owner and resort to fear-based aggression.

Managing Fear-based Aggression

Managing fear-based aggression requires a team approach, involving the owner, veterinarian, and a professional animal behaviorist. The primary management options are removing triggers, redirecting aggressive behavior, and medical management.

Managing triggers involves separating the dog from the trigger. For example, if unfamiliar house guests trigger fear-based aggression, the dog should be kept in a separate room when unfamiliar people visit.

Redirecting the behavior involves counterconditioning to train the dog to perform behaviors that are counter to the problem behavior. This can be done through operant or classical conditioning. In both counterconditioning scenarios, the dog should be asked to perform behaviors it already knows, and these behaviors should be reinforced. Overall, a fearful dog should learn to seek its owner’s direction during a threatening situation.

Medical management is indicated for fearful dogs that are overly reactive and do not follow direction or take rewards. This typically involves serotonin pathway reactivation to reduce amygdala-induced reactivity. Dr. Ciribassi recommended selective serotonin reuptake inhibitors (SSRI): fluoxetine (Prozac), paroxetine (Paxil), and sertraline (Zoloft). He also recommended clonidine and trazodone, both of which can be used situationally and in combination with an SSRI.

Dr. Ciribassi cautioned against managing fear-based aggression with amitriptyline because dogs can quickly build a tolerance to it. In addition, benzodiazepines would not be a good medical management option because they can disinhibit fear, possibly encouraging a dog to display aggression.

Recommended Reading

For veterinary practices, Dr. Ciribassi recommended Blackwell’s Five-Minute Veterinary Consult Clinical Companion: Canine and Feline Behavior as a reference on veterinary behavior. He also recommended Decoding Your Dog: Explaining Common Dog Behaviors and How to Prevent or Change Unwanted Ones, written by diplomates of the American College of Veterinary Behaviorists, as a useful reference for dog owners.

Dr. JoAnna Pendergrass received her Doctor of Veterinary Medicine degree from the Virginia-Maryland College of Veterinary Medicine. Following veterinary school, she completed a postdoctoral fellowship at Emory University’s Yerkes National Primate Research Center. Dr. Pendergrass is the founder and owner of JPen Communications, a medical communications company.