SIMPLIFIED: The Aggression Study

The studies performed by the Center for Canine Behavior Studies are filled with an extensive amount of statistics and science-based language. A guest contributor, Robin Grimm, has joined CCBS to help translate our important study results into an easier-to-read version below.

So often, those of us who adopt dogs are unaware of the history of our new companion. As such, some dogs may display challenging behaviors because of negative prior experiences, and as dog owners, sometimes we feel at a loss to correct such issues. One particularly disturbing trait is that of aggression – and often, if not managed properly, leads to dogs being returned to shelters, and ultimately euthanasia. In a 2021 study by the Center for Canine Behavior’s Nicholas Dodman along with Ian Dinwoodie and Vivian Zottola, the question of how owners address canine aggression, and the outcomes of these choices was investigated. The study (which consisted of responses to a survey representing 963 dogs) was aimed at learning which types of professionals, if any, people sought; what types of training methods, equipment, or behavior modification was employed; and what types of medications were utilized. The following categories of aggression were reported by owners and reviewed:

• CA - Conflict Aggression (24%) – Inwardly directed toward familiar people

• HA – Interdog Housemate Aggression (35%) – directed toward dogs within the household

• FA (49%)– Fear Aggression toward people – outwardly directed aggression toward people outside of the household

• FAD (72%) – Fear Aggression toward dogs – outwardly directed toward dogs outside of the household

• PA (14%) – Predatory Aggression

The study also considered the types of professions from whom owners sought advice. Following is a list of credentialing bodies considered:

• CCPDT – Certification Council of Professional Dog Trainers

• ACVB – American College of Veterinary Behaviorists

• ABS – Animal Behavior Society

• IAABC – International Association of Animal Behavior Consultants

The largest percentage of dogs (48%) were rescues, while 23% were from breeders with a small number (1%) were from pet stores. The median age of acquisition was about six months.

Of the 963 dogs represented, only 56% had owners who reached out for professional help. Important to note is that 22% of the dogs saw a veterinarian – and 15% of those were found to have a medical issue relevant to the behavior problem – most often pain. The most common approach that owners took was to seek out the help of a trainer – with several seeing multiple trainers. Owners overall perceived this to be helpful. A substantial portion of that group saw credentialed trainers certified by the CCPDT. An overwhelming number (74%) of the participants indicated that credentialed trainers were helpful for the treatment of aggression.

Another option that many respondents chose was a behavior consultant. Again, the results were positive with 71% indicating a positive result. One hundred ninety-six dogs (20%) saw a credentialed consultant with 58% crediting this as helpful for the treatment. The most common credentialed consultant was a Certified Behavior Consultant Canine-Knowledge Assessed (CBCC-KA) which is awarded by the CCPDT. People also chose certified consultants under the ACVB known as Diplomate of the American College of Veterinary Behaviorists (DACVB) with an 81% positive report as well as Associate Certified Applied Animal behaviorist (ACAAB) certified by the CAAB with a 58% positive report.

Interestingly, dogs with CA who were brought to behaviorists who were credentialed had 18.95 the odds of a positive response in comparison to .10 odds for those without regard for credentials. Ironically, however, dogs with FAD showed 2.37 odds of improvement regardless of the consultant’s professional credentialling and only 0.26 odds of improvement after seeing a DACVB-certified veterinary behaviorist.

The study continues by considering methodologies for improvement including training methods, training equipment, behavior modification programs, behavior modification and training techniques, medications, and alternative medications. Training was an approach employed by an overwhelming majority (99%) of owners who attempted to use basic obedience alone or in combination with other techniques to treat aggression. Eighty two percent (82%) of dogs that were trained were exposed to reward only methods while the other 18% received some form of punishment along with reward.

Ninety seven percent of the dogs were managed with training equipment as part of the treatment. The most significant impact with equipment came from the use of a martingale collar, which resulted in 26.10 odds of a positive response, followed distantly by slip/choke/prong collars at 2.38 odds of improvement. The use of muzzles and anti-bark collars reduced the odds of a achieving a positive response. Important to remember is that only 56% of respondents sought out professional help while 99% engaged in training and 97% utilized equipment – so much of this training was done without professional supervision.

Thirty one percent of the dogs were exposed to behavior modification programs with 68 of those dogs exposed to counterconditioning (CC) and 40 to systematic desensitization (SD). One hundred sixty dogs had a combination of both CC and SD. The combination of CC and SD was most successful and resulted in 2.37 odds of a positive response. Ninety eight percent of the dogs were exposed to specific behavior modification techniques with particular emphasis on the type of aggression. For example, there were significant odds of progress with techniques designed to improve dog-owner communication in dogs with CA, whereas habituation showed more promised for dogs with FA. Short frequent sessions showed the most promise for dogs with PA and participating in dog sports helped dogs with FAD.

The study also considered the use of medications with 202 dogs receiving medication as a treatment option for aggression. The vast majority were on fluoxetine (Prozac) with Trazadone being the next most common prescription. A slightly smaller number of dogs were treated with alternative medicines, with only nutraceuticals (diet-based treatments) showing a positive response. Generally, and somewhat surprisingly, no medication increased the odds of an aggressive dog responding positively to treatment. Past studies have shown that drugs like fluoxetine have been shown to successfully reduce aggression, so it is possible that owners were not complying with dosage or did not try the medicine for a long enough time

After consideration of the various professional help and training techniques, a few clear patterns emerged. Of significant note is that dogs with CA showed a dramatically greater improvement when taken to a credentialed behavior consultant contrasted with an actual negative result with those who opted for a consultant with unknown qualifications. Further, unexpectedly, martingale use seemed to help as well – which was unusual given that collars and harnesses typically are not part of retraining with this type of aggression. Finally, improved dog-owner communication helped with CA dogs as well.

Dogs with HA did not show much success with training methods or equipment. Any positive result that did come happened through short and frequent sessions. Part of the challenge in analyzing this behavior and any impact that medicine might have had is understanding which of the feuding dogs was being treated.

Dogs with FA did not benefit from reward or punishment-based techniques. A challenge with counterconditioning and situational desensitization (CC and SD) is that often they are hard for an expert to explain to owners and require monitoring and adjustment, which is not feasible for most dogs on a daily basis. Dog owner communication, habituation, and frequent training sessions did slightly increase the odds of improvement. Constant benign exposure appears to help these fearful dogs.

Dogs with FAD had similar responses to methods and programs to those with FA. The positive responses came through habituation, relaxation protocols, and in this case, participation in dog sports. Dogs with FAD did benefit somewhat from seeing a behavior consultant. For these dogs, though, it appeared that there was less success with a DACVB-credentialed behaviorist. This possibly is the result of the higher cost for these professionals – thus less frequent visits or a shorter treatment program.

Finally, for dogs with PA, training by credentialed dog trainers with short, frequent sessions appeared to produce the best results.

Overall, owners felt in 82% of the cases that their dogs’ aggressive situation had improved, with many of them improving after their owners sought professional advice. Overall, DACVB-credentialed behaviorists had the highest proportion of success. As has been the case in other similar behavior studies, about 15% of the dogs were diagnosed with a contributing medical condition - supporting the fact that dogs should have a veterinary health evaluation prior to any behavioral/training program to rule out any physical causes. Ultimately, the most important message from this study is that owners with dogs dealing with aggression are best suited by reaching out to a credentialed behavior expert who can work with them on counterconditioning and situational desensitization. Aggression in any of the identified forms, left untreated, is dangerous for both human and hound – and so often leads to dogs being surrendered with extremely poor chances of rehoming. Further, while the study did not show positive outcomes correlating with medication, use of pharmaceuticals should not be ruled out – and should be part of a broader discussion with a credentialed behaviorist or veterinarian – as there are still too many unknowns in these responses to determine why medications did not work whereas in past studies they have.

Because so many of our dogs come to us through adoption and rescue, we may never know the source of their negative behavior. As owners, we are trying to “undo” damage that was done long before the dog joined our families. With aggression, the consequences of a mistake in managing the behavior may be grave for humans and the dog. Sadly, only 56% of respondents sought professional help – and while many more employed training techniques on their own, it seems that, given the positive outcome of seeking professional help, many more dogs could live out their lives happy and far better adjusted if their owners sought the right type of professional help and employed recommended behavior modification programs and techniques.