The terms possessive aggression, food-related aggression and resource guarding are often used to describe behaviour patterns used by a dog to control access to a perceived valuable item.
Common triggers for resource guarding include:
- Food (in their bowl)
- Dropped/scavenged food
- Stolen items
- Access to the bed/sofa/their own bed
- Access to a family member
Why does possessive behaviour develop?
Possessive behaviour will often begin as normal, innocent play, exploratory or attention-seeking behaviour. If managed correctly, this behaviour will extinguish as the young dog matures and learns through repetition more appropriate sources of play or means to obtain owner attention. However, if managed incorrectly, learning can quickly cause this scenario to become problematic.
The value of the item can inadvertently be increased by over-the-top human reactions, causing the dog to become anxious about relinquishing it or determined not to. After all, a dog living on the streets would rely on this kind of observational learning and would not survive if he caught his dinner and then gave it up to any dog that approached him.
Possessive behaviour is genetic, although the instinct may be stronger in some dogs than others. Learning is also an important factor. This may start in a dog’s early weeks based on his mother’s behaviour or if he were deprived (either due to sibling competition or neglect), or learning may play a role later on.
A typical scenario might be that an adolescent dog steals a tea towel, which is then followed by their owner quickly approaching, possibly some words of frustration and an attempt to snatch the tea towel back. The dog may feel this is fun and repeat the behaviour. However, emotions can quickly switch into fear and anxiety within one confrontational interaction or over time.
The triggers for this behaviour can also generalise, so what started with a stolen tea towel now applies to all toys, laundry, paper, tissue, etc. Medical differentials must be excluded including pain (including gut pain) and conflict pertaining to eating due to airway obstruction, regurgitation, dietary/gut issues, dental and skin issues, etc.
How do you know when a patient has an issue with possessive behaviour?
- Evasive behaviour, such as grabbing a toy/item and then running away and evading contact when approached. This applies to many puppy and adolescent dogs, and is particularly prevalent in the increasingly popular working Cocker Spaniel and Cockerpoo
- Rapid ingestion of inappropriate food or items
- Fearful and/or submissive body postures when in possession of an item
- Hypervigilance in relation to items or family movements around items
- Fearful body language such as displaying the whites of the eyes, dilated pupils, lip licking, yawning and cowered posture
- Standing over items/body blocking
- Growling or barking if approached
- Lunging/snapping/biting if approached (this can escalate to be the case at increased distances)
Results suggest that owners are good at identifying aggressive behaviour, but not warning behaviour (Jacobs et al., 2017), placing owners at increased risk of injury.
What advice should be given to a client whose dog is displaying any of the above behaviours?
- Carry out a full health check
- Recommend an ABTC registered practitioner (Dinwoodie et al., 2021)
This could be an animal training instructor (ATI) if the patient in question is a dog who is at a stage of being evasive about relinquishing items. Identifying and responding correctly to non-aggressive behavioural patterns will decrease the likelihood of future aggressive responses (Landsberg et al., 2012).
A clinical animal behaviourist (CAB) should be recommended if the behaviour has reached problematic or aggressive levels. It is up to the behavioural practitioner to ascertain the triggers for the aggression and who the aggression is directed towards (family members or household dogs), and through discussion provide an adequate risk assessment, followed by a plan which manages triggers and mitigates risks, and in time modifies the dog’s behavioural and emotional responses around that trigger (Jacobs et al., 2018a; Pfaller-Sadovsky et al., 2017).
If the type of aggression is misdiagnosed, or the trigger or level of risk is not correctly understood, this could negatively impact successful management (potentially leading to human injury, relinquishment of the dog or euthanasia) and hinder behaviour modification.
In many cases, guarding behaviour moves beyond defence of the resource and through learning becomes entangled in a web of anxiety and conflict. At this point, triggers for guarding behaviour have often generalised so it is difficult to manage and predict, and guarding can often be triggered not by the item but by other sources of stress. This is a very high-risk situation and expert help must be sought out. An American study showed that aggression over food or non-food items was the most common reason for dogs to be considered unadoptable (Mohan-Gibbons et al., 2012).
- Do not challenge/confront the dog
There is a clear correlation with the use of positive punishment and increased aggressive responses (Casey et al., 2014).
- “Ignore, exchange or recall”
As a general rule, this response takes the focus off the food/item and puts the focus on the dog performing an appropriate behaviour for a reward. The food/item can then be removed when safe to do so.
Of course, problems will occur when the items/foods in question may be dangerous and there is a risk of ingestion or, as is often the case when the problem reaches a level where a behaviourist is called in, exchanging or recalling an animal is not an option, even for the highest value rewards. This is where that web of anxiety and fear needs to be unpicked, and this web will be built from numerous repetitions of traumatic experiences and confrontations. This is where management of triggers is key (Jacobs et al., 2018b). Management may involve removing at-risk items (eg bones/toys), changing feeding locations, restricting access to resources and areas, etc.