By Jacqueline Wilhelmy, CBCC-KA, MS, VMD, DACVB
There is, perhaps, nothing more satisfying than using operant conditioning to shape a dog’s behavior. To owners, it can look like magic. To dog trainers, it is bittersweet but rewarding to send a client out into the world with the skills to keep their dog safe and well-behaved. For unintentionally reinforced behaviors—jumping, barking, mouthing, pulling on lead—avoidance of positive reinforcement and use of negative punishment can work wonders. Positively reinforcing a stay, recall, send to place, or leave it (while setting the dog up to avoid self-reinforcement of incompatible behaviors) can provide invaluable life skills for owner and dog.
We’ve all walked into a situation in which we worry that knowledge of the four quadrants won’t be enough to explain the motivations behind a dog’s behavior, or resolve the owner’s concerns. Perhaps the dog shows a fight, flight, or freeze response, but one so exaggerated or easily triggered that the warning signs are almost non-existent, or the owners cannot “get through” to the dog once he goes over threshold. Perhaps the dog is a whirling dervish, completely unable to engage or focus. Or, despite adequate exercise and enrichment, he barely shows interest in performing known cues for even the most enticing of motivators.
Dogs are not robots, and approaching canine behavior from a strictly Skinnerian perspective tends to overlook important developments in our understanding of neurophysiology and cognition. First, we must consider that operant conditioning is only one type of associative learning. We tend to forget about classical conditioning, even though conditioned emotional responses are one of the strongest associations the brain can make. Classical conditioning is also an incredibly powerful tool when it comes to “fixing” behavior problems rooted in anxiety, frustration, or fear; if we can change the physiologic response to the stimulus, then we should eliminate the animal’s undesirable behavior.
Secondly, we have to consider the limbic system and non-associative learning. Every owner assumes that their dog will habituate. Many think that if they just expose the dog to enough people, dogs, and places, he or she will take it all in stride. However, we know that if the dog’s experience falls onto the negative side of the scale, even by a small margin, that she is potentially at risk for becoming sensitized to that stimulus. Over time, every experience provokes a reaction—with varying degrees of severity—from the limbic system, and the dog starts to perceive stimuli in that category as increasingly threatening.
So what is this limbic system, and why is it important? Also, what happens if the limbic system is predisposed (by genetics or epigenetics) to work incorrectly? The limbic system is a collection of structures in the brain that are in part responsible for mediating behavior, long-term memory, and emotional response. We all have one and, in fact, the limbic system is one of the oldest parts of the mammalian brain. In both children and dogs, the less well developed area of the brain is the prefrontal cortex. This part of the brain acts as a brake or filter on impulsive, emotional responses to stimuli. Interestingly, in dogs who exhibit impulsive aggression—that is, dogs who don’t escalate appropriately up the “ladder of aggression”—serotonin receptor affinity in this part of the brain is altered relative to normal dogs.
When the limbic system becomes activated, it feeds down through several different axes, at least two of which activate release of stress hormones from the adrenal glands. One of these, the HPA axis, involves the release of the long-lasting stress hormone cortisol, which is integral to the concept of “trigger stacking.” The other, the sympathetic adrenomedullary system, involves release of fast-acting, short-lasting stress hormones (adrenaline and noradrenaline). These chemical messengers are responsible for behavioral response to a perceived threat: that is, the fight, flight, and freeze responses.
These axes are also responsible for other behavioral manifestations of “stress,” whether that stress be distress or eustress (moderate or normal psychological stress that can be beneficial for the experiencer). These manifestations are varied, but may include pupil dilation, ear pinning and pricking, lip licking, yawning, piloerection, tail wagging, and raising a forepaw. They may also include disengagement from the owner, disinterest in food, and inability to respond to known cues, as well as persistent jumping, licking, mouthing, and mounting that do not respond to negative punishment.
Stress and “fear” (the fight-flight-freeze response) are normal components of canine and for that matter, human behavior. Of course, behavioral medicine can help owners understand what is and what is not normal canine behavior. One of its greatest values, however, lies in the diagnosis and treatment of dogs and cats whose behavior results from excessive or exaggerated signs of stress or “fear.”
Aggression is a normal part of canine communication. However, in most dogs it is limited to understandable contexts: unfamiliar people or dogs entering the house or yard, attempts by a person or dog to remove a valued resource, pain, etc. However, some dogs respond with a fight, flight, or freeze response in more benign or less understandable contexts, or in a rapidly escalating or exaggerated fashion. We’ve already mentioned that dogs who exhibit disinhibited aggression have altered cortical serotonin receptor affinity. In addition, dogs euthanized due to aggression towards familiar people had altered levels of serotonin metabolites in their CSF. Dogs diagnosed with canine compulsive disorder exhibited changes in the macroscopic structure of their brain, changes analogous to those seen in the brains of humans with OCD.
One of our primary goals in behavioral medicine is to help owners understand the science behind their dog’s behavior, and how that behavior is likely to progress over time. Addressing any existing medical conditions should reduce a dog’s baseline level of stress, as well as potentially eliminate triggers related to pain or physical discomfort. There are an increasing number of behaviors that have been shown to stem from underlying physical disease: excessive licking of surfaces and fly biting in dogs , tail chasing and unprovoked aggression in Bull Terriers , and “psychogenic” alopecia in cats.
As veterinary behaviorists, we also have tools in addition to management (intended to prevent further sensitization) and behavior modification. The number of anxiolytic medications available has expanded significantly in recent years. Serotonergic medications such as SSRIs and TCAs have been FDA-approved for the treatment of separation-related problems in dogs, and some have been shown to facilitate treatment of problems ranging from aggression and compulsive behaviors to predatory behavior. Benzodiazepines and buspirone continue to serve as older but still useful treatments, particularly for phobic behaviors. Supplemental medications such as trazodone and supplements such as L-theanine, alpha casozepine, Magnolia and Phellodendron extracts, tryptophan, and huperzine A provide additional options, including polypharmacy. Increasing evidence for the use of as-needed medication exists, for issues ranging from situational fear and veterinary handling to noise aversion.
Behavior modification (in the form of both operant and classical conditioning, as well as non-associative learning) is crucial to the treatment of many dogs exhibiting an abnormal or undesirable stress or fight-flight-freeze response. This veterinary behaviorist is grateful to have CBCC-KA behavior consultants who can work with clients on implementing a management and training plan in-home, over a period of weeks to months. Perhaps our goal, as veterinary behaviorists and trainers, should be to work together in order to provide the greatest possible benefit and range of tools to owners and their dogs. This is especially true for those canines who struggle—whether due to stress or fear—to remain in an “operant,” or thinking, frame of mind.
Dr. Wilhelmy completed her undergraduate work in biochemistry at the University of Pennsylvania, and went on finish a master’s degree in chemistry. She graduated from the University of Pennsylvania School of Veterinary Medicine, and remained to pursue an internship and then a residency in veterinary behavioral medicine. She has treated feline and canine patients presented for separation anxiety, compulsive behavior, inappropriate elimination, affective aggression, environmental phobia, predatory behavior, thunderstorm and noise fear, and generalized anxiety disorder. Dr. Wilhelmy has also spent time with the New Bolton Center’s Section of Reproduction & Behavior, as well as the MJR-VHUP’s Exotics Service, learning about the behavior of other domestic and wild species. She is a Diplomate of the American College of Veterinary Behaviorist.
In her spare time, Dr. Wilhelmy enjoys learning about real world applications of behavior modification (and there is always more to learn!). She has taught agility and basic manners at a local dog training club, Y2K9s. Although she has dabbled in herding and continues to enjoy recreational canicross, her true passion is dog agility. She is owned by two Border Collies, Mer and Obi, who amusingly have more letters after their names than she does.