Author: Evie Van Hove
In the field of dog behaviour therapy, the most challenging cases are rarely those where ‘a dog is aggressive’. The most complex cases often involve situations where multiple factors are at play simultaneously: tension between dogs in the same household, a lack of predictability in the daily routine, heightened irritability, unclear communication between humans and dogs, and previous interventions that have only served to escalate the problem further.
This case involving Gust and Bas from Zemst is a striking example of this. Both dogs are Great Danes, and there is also an older French Bulldog in the family. At the time of the initial assessment, Gust was a young, unneutered male of about eighteen months, whilst Bas was an older male of nearly seven years. The request for help primarily centred on aggression between the dogs themselves, with incidents that seemed unpredictable and involved biting that caused bleeding. Other behavioural issues were also at play, such as restlessness, tension around food, separation anxiety, pushy behaviour, reactions at the door, and difficulties in daily interaction and handling.
Why this case is important for vets, behaviourists and owners
This case clearly demonstrates why a modern, academically grounded approach to canine behaviour is essential. Several differential diagnoses were considered in the case file, including anxiety- and frustration-related aggression, inter-dog aggression, resource guarding, redirected aggression and social conflict behaviour. Furthermore, there was a lack of socialisation, limited predictability in the context, increased agitation in Gust and clear signs of stress in Bas, who lowered his body and began to keep his distance. It was also noted that, following incidents, Gust appeared to be startled by his own behaviour, which clinically often indicates an escalation pattern that cannot simply be dismissed as ‘dominance’.
For professionals, this is a key point: aggression between dogs in the home is rarely a linear problem with a single cause. It usually involves a dynamic interplay of arousal, communication difficulties, environmental pressure, learning experiences, medical factors and human interactions. In this case, there were also medical considerations, including previous health issues, a history of pain relief/medication, and the explicit recommendation to have medical causes ruled out by the vet. Fluoxetine was also discussed as a possible supportive option.
The context at referral: unpredictability, tension and escalation
What made this case particularly difficult for the owners was, above all, the unpredictability. The intake report explicitly stated that the behaviour was not easily predictable, that bite inhibition was inadequate, and that the dogs were already being kept separate to prevent further incidents. There had also been growling over food, following which separate feeding had been introduced. In addition, it was noted that the daily routine was still insufficiently clear and predictable, that consistency needed to be worked on, and that walks were being taken using a slip lead.
It is precisely this combination that is relevant from a behavioural science perspective. An environment with high levels of tension, little predictability and management measures that are not yet sufficiently developed increases the risk of conflict, particularly in a household with multiple dogs and potential competition over space, food, attention or freedom of movement. The report also rightly points out that dogs do not form a ‘pack’ in the popular sense of the word, but are better understood as coexisting individuals who may compete for resources. This is a fundamental principle within contemporary canine behaviour therapy.
‘What made this case particularly difficult for the owners was, above all, the unpredictability.’
The problem with aversive training
A crucial element in this story is that the owners had previously sought help, but were then dealt with by a therapist who used aversive techniques. According to the owners, that intervention ended so badly that one of the dogs nearly died as a result. This fact highlights a reality that is still too rarely acknowledged within the sector: punishment, intimidation and physical coercion are not neutral techniques. Not only do they pose risks to the dog’s welfare, but they can also suppress warning signals, increase stress, cause the aggression ladder to escalate rapidly and seriously jeopardise safety.
This also aligns with an important principle mentioned in the case file itself: punishment can cause dogs to unlearn their warning signals and move up the aggression ladder more quickly, whilst simultaneously damaging the relationship with the owner. For professionals, this is not a minor detail, but a key point. When dogs do not become safer as a result of an intervention, that intervention is ethically and functionally problematic.
Evie Van Hove’s approach: management, observation and positive behaviour therapy
Following Evie Van Hove’s intervention, an approach was adopted that was consistent with current academic principles in canine behaviour therapy: stabilise first, then analyse, then build up carefully.
In practical terms, this meant, amongst other things, that the dogs were not simply placed together again in high-risk situations. Work was carried out in separate contexts where necessary, walking them separately when tension became too high, controlled exposure, structured training and creating greater predictability in daily life. Attention was also paid to the choice of equipment: Gust was fitted with a well-fitting harness early on, and later Bas was also given a harness; we also worked with, amongst other things, a drag line to enable safer and more controlled guidance.
In addition, there was a strong focus on skills that are indispensable in many aggression cases: being able to seek attention, orienting towards the handler, walking alongside in a controlled manner, and being able to remain stationary without additional tension. In the case file, the exercises ‘look’, ‘follow’ and ‘stay’ were developed step by step, with a clear focus on error-free learning, reward-based training and avoiding unrealistic expectations. It was explicitly advised not to ask too much, not to repeat commands endlessly, and always to train at a manageable level. Sniffing and mental stimulation were also incorporated, including through search tasks using cones and food enrichment.
For fellow behaviour therapists, the methodology is particularly relevant here: not just ‘training the dogs’, but supporting the entire system. Work was done on recognising body language, on coordination between the various carers, on calmer door management, on safer walking environments, on better reading of stress signals and on respecting personal space. In other words: not correcting when things escalate, but preventing escalation through better setting control.
The progress: not spectacularly fast, but sustainable and genuine
As is often the case with serious aggression cases, progress was neither magical nor linear. There were occasional moments of relapse or renewed tension, including during walks. That is why it was decided to temporarily stop walking together until the situation became more manageable again. From a professional point of view, such choices are often far more important than spectacular training sessions: safety and prevention form the basis of behavioural change.
Nevertheless, clear progress became apparent as things went on. The walks together became calmer as time went on. In the garden, they were once again able to practise together in a controlled manner, with Gust on a long lead and with sufficient management to allow Bas some peace. Whilst Bas initially still showed clear signs of stress, such as looking away, panting and withdrawing, it was explicitly noted that these signs were already less pronounced than before. At the same time, the owners noticed that Gust was becoming calmer as a result of the combined approach. Other practical skills, such as calmly putting on a harness, being put on a lead and building trust around the van, were practised step by step.
Perhaps the most important element in this story is that the problem was ultimately resolved, provided there was plenty of practice, plenty of patience and consistently sustained guidance. About a year after the last home session, the owners confirmed that the situation had remained stable. That long-term result is precisely what high-quality dog behaviour therapy should be about: not a quick, superficial fix, but a lasting behavioural change that holds up outside the therapeutic setting.
What this case teaches us about dog-to-dog aggression in the home
This case offers a number of important lessons for vets, fellow therapists and owners.
Firstly: aggression between dogs in the same household always requires a comprehensive analysis. Age, social maturity, pain, frustration, resource competition, living environment, predictability and learning experiences must all be taken into account. In this case, Gust was also at an age where problem behaviour is more common in intact males, whilst Bas appeared to be the more withdrawn of the two.
Secondly: aversive methods are not only outdated, but potentially dangerous. Particularly in cases involving inter-dog aggression, they can heighten tension, impair communication and increase the risk of serious incidents.
Thirdly: positive dog training is not a ‘soft’ alternative, but the most logical and safe way to build behavioural change. Working positively does not mean doing nothing; it means systematically working on management, predictability, emotional regulation, learning processes and safety.
And fourthly: time is not a detail, but a therapeutic factor. Anyone wishing to manage a case involving aggression between dogs must honestly prepare owners for repetition, practice, nuance and patience. There are no quick fixes in cases like these. There is only solid work, carried out consistently.
In conclusion
The case of Gust and Bas from Zemst demonstrates what dog behaviour therapy can be at its best: meticulous, analytical, welfare-focused and scientifically grounded. It does not start from a place of blame or conflict, but from observation, safety and learning principles. It does not suppress the symptoms, but addresses the causes and context. And above all: guiding owners in the realisation that real progress is possible, as long as one is prepared to invest in time, practice and a positive approach.
That is precisely what Pettherapy.be stands for: behavioural therapy for dogs that looks beyond visible behaviour, and that helps humans and animals to live together safely and sustainably once again.
Evie Van Hove holds a Postgraduate Diploma in Clinical Animal Behaviour and is a qualified puppy coach, dog trainer and behaviour coach. She has been the manager of Pettherapy.be since 2021.
