Could Pain Be the Hidden Cause of Your Pet's Behavior Issues?
How pain influences behavior and how it shows up
During the International Veterinary Behavior Symposium in 2019, I participated in a workshop with other veterinary behaviorists to discuss a significant welfare issue affecting our patients—pain and discomfort.
We all shared similar experiences—pain in some of our patients was going undiagnosed and untreated, and it was contributing to the behavioral issues that brought them to our clinics. These cases were by no means uncommon—depending on the practice, the proportion of dogs and cats with a suspected painful condition ranged from ~25% to above 80% of the total cases seen. The most common sources for pain in these dogs and cats were diseases affecting the joints or spine, as well as the skin, ears, and gut.
What pain is
Pain is a complex experience involving both emotions and physical sensations. Here’s how it’s defined by the International Association for the Study of Pain (IASP):
an unpleasant sensory and emotional experience associated with, or resembling that associated with, actual or potential tissue damage.”
The IASP is careful to point out that the inability to communicate does not negate the possibility that a human or nonhuman animal experiences pain.
The experience of pain is unique to the individual—it is subjective and can be influenced by fear, anxiety, stress, past learning experiences and memory, as well as the animal’s social and physical environment.
Assessing pain in dogs and cats
Verbal humans can self-report their experiences of pain. If you’ve been to the doctor recently, you’ve probably been asked to rate your pain using a scale. To assess non-verbal patients, including dogs and cats, pain is assessed using behavior. When it comes to assessing acute pain, pain developing abruptly from trauma, surgery, or an infection, veterinarians have multiple validated tools to use. We use them in the exam room and cage-side, and these tools incorporate behavior, body posture, and facial expression to help us understand the animal’s experience of pain and determine how best to treat it.
It’s more challenging, however, for veterinarians to evaluate animals for chronic pain. Chronic pain is associated with several common diseases in dogs and cats including arthritis, intervertebral disc disease, and certain cancers. It is both pathologic and maladaptive—this type of pain can persists beyond the course of the disease, it’s not associated with healing, serves little to no biological purpose, and also negatively impacts emotions, cognition, and behavior. Chronic pain is tricky for veterinarians and pet parents to identify because the symptoms can be subtle and develop gradually. Since those living with their pets know them best, caregiver assessment tools are considered the foundation for chronic pain assessment in dogs and cats. Education is needed to use these tools effectively, however, as gradual behavior changes are easily missed or ascribed to other issues, such as aging and behavioral problems.
How pain shows up in behavior problems
Since pain is both an emotional state AND also influences emotions and behavior, its relationship with problem behaviors is quite complex. Chronic pain is the most common form of pain experienced by our patients, and it tends to show up in one of three ways:
Pain is the primary cause for the behavior problem
Unidentified pain is causing some aspect of a complex behavior problem
Pain is exacerbating one or more symptoms of the behavior problem
Pain as the primary cause for the behavior problem
Animals in pain are understandably more defensive, and that defensiveness can show up as aggression. A study conducted at the University of Lincoln in the UK compared dogs presenting with aggression who had painful conditions to those who did not. Several distinct themes emerged among the dogs experiencing pain, including:
being described by caretakers as having inconsistent reactions or a “Jekyll and Hyde” personality
responding aggressively when approached at rest
reluctance to move or exercise
Additional red flags for pain in dogs and cats we’ve found at our clinic are responding aggressively during petting or handling or when approached around valued resources such as food and resting areas. In some cases, the animal had never before snapped or bitten in these situations. In others, more subtle signs of discomfort, such as turning away, leaning away, lip licking, and even growling had been present, but the animal only recently escalated to biting.
While we see pain showing up as aggression in the vast majority of our cases, other issues that frequently have pain at the source are fear of loud noises developing in older dogs, house soiling in both dogs and cats, fly-snapping, excessive licking and pica, night-waking in dogs, and attention-seeking.
Unidentified pain is causing some aspect of a complex behavior problem
These are some of the trickiest and most frustrating cases for everyone involved. Usually there is a primary behavioral issue, but some aspect of the behavior problem is caused by pain or discomfort. One that comes to mind is a recent case seen at my practice, where the dog presented for separation-related behaviors. Most of this dog’s separation-related behaviors responded beautifully to treatment, but one behavior, blanket chewing, persisted. The pet parents were understandably frustrated at this apparent lack of progress, but once that dog was placed on a strict hydrolyzed protein diet to treat their suspected food allergy, the blanket chewing resolved.
We can also see unidentified pain and discomfort show up as sudden behavioral regression in a patient that had been stable for months, or in cases which improve less than expected despite diligent treatment.
Pain is exacerbating one or more symptoms of the behavior problem
This is probably the most frequent way we encounter pain in our practice. Pain influences emotion, and it is also influenced by emotion. That means if your pet is feeling fear and anxiety, their perception of pain will greater. And if they are experiencing pain, that can make their fear and anxiety worse a they may become more withdrawn, irritable, and reactive. This ties into the concept of allostatic overload. Our bodies are made to deal with short term stressors, but when stress (for example from chronic pain) lasts too long or is too intense, it affects all of the other body systems including the brain and mental health.
Behaviors associated with pain—when we see these we’re not sure pain is present but they indicate further investigation is needed
Sometimes animals do things that just seem weird or out of place, and if you’ve been watching your dog or cat do that particular behavior for a long time, you just might think it’s normal for them. The example of this we encounter most often is an abnormal sitting posture (we call it a sloppy sit or side-saddle sit, with one leg tucked under the body). While it’s possible that this may just be the way your dog or cat sits, it’s also very possible that your pet is sitting that way because they are compensating for discomfort that makes sitting in the typical manner unpleasant. This particular sitting posture has been associated with abnormal gaits in pugs, orthopedic disease such as cruciate ligament tears, and spinal cord disorders. Other examples of behaviors associated with pain include abnormal scratching of the head and neck, “phantom scratching” (ie scratching in the air without making contact with their body), air licking, fly snapping, frequent stretching, body shaking (especially interrupted body shaking), and excessive licking of objects or others. If these are showing up in your pet, it’s a good idea to look for those signs that it’s not all in their head.
What you can do
Since arthritis is the most common source for pain in dogs with behavior problems, I’m going to focus on how you can screen for that below. Gut and skin disease are close seconds in my practice, and you can find common signs for gut and skin disease to look for here.
If you’ve seen any of the issues reviewed above in your pet, gather some information and contact your vet for an evaluation.
Use a pain assessment tool that’s been validated and designed for pet parents. This one is for cats and this one for dogs. Both are short and simple to complete.
Take a video of your pet engaged in routine activities around the house, such as walking, jumping, using the stairs, and using the litter box. It’ll be easier for your vet to assess your pet’s posture and gait in their normal environment than when they are stressed and anxious at the clinic. Here’s how to do it in a way that’ll give your vet the most information possible.1
Once you’re able to review this information with your vet, they may want to do additional testing such as taking x-rays. If it’s unclear whether or not pain is contributing to your pet’s behavior, a therapeutic trial with a pain medication that’s safe for your pet may be the next best step to help clear things up.
I’ll devote a future issue to some of the myths that get in the way of recognizing and treating pain in pets. In the meantime, if you know a pet parent or a veterinarian that would appreciate reading this article, please share it.
All my best, Kelly
Insightful Animals is operated by me, Dr. Kelly C. Ballantyne, DVM, DACVB. I’m a vet behaviorist, nature fanatic, bird artist, wife, and mom to two hilarious Ragdoll cats, Pipit and Towhee. In my work-life, I consult directly with pet parents and veterinarians on a range of behavior problems in dogs and cats.
My goal is to offer hope to pet parents navigating behavioral challenges while demystifying the science of animal behavior and cutting through the fog of misinformation surrounding it. This newsletter is free to everyone but cannot exist without your help. To support this effort, subscribe or upgrade below:
While this video shows how to get gait footage for dogs, the same basic principles can be applied to cats.