Active animals can still have pain
What spunky spaniels, pro athletes, and middle-aged veterinary behaviorists have in common
This post is the second in a series covering common myths surrounding pain in dogs and cats.
Myth: My pet can’t be in pain because they still [go on walks, chase squirrels, jump on the furniture, etc.]
There’s a lot wrong with this myth, but here are some of it’s most obvious problems.
First, animals (including humans) are known for being active even when in severe acute pain. Picture a gazelle running away from a lion with a big tear on their rump, or a human athlete continuing to play a game on a broken bone. While one of acute pain’s adaptive functions is to alter behavior to minimize further damage and optimize healing, pain sometimes just can’t compete with other motivations.
If your dog or cat has ever needed surgery, you’ve already faced the daunting task of restricting or reducing their activity while they are recovering. Even with a good pain management plan, these animals are likely not pain-free, and it’s still not easy to keep their activity restricted. My cats, who I think fall fairly low on the spectrum of athleticism and activity,1 challenged most of my efforts to prevent their wrestling, chasing, pouncing and jumping when they were recovering from their neuter surgeries last year. Thankfully, neutering is a pretty minor surgery, and they had the assistance of effective medications to manage both their pain an activity levels, so they healed quickly and without complications.
Not all pet parents or pets are so lucky. When I was a fourth-year veterinary student on an orthopedic surgery rotation, I witnessed first-hand how little of an effect pain can have on highly motivated behaviors. Our patient was a young spaniel who came to the hospital after getting hit by a car. Her pelvis was shattered, and putting it back together required a couple of veterinary surgeons, a few nurses, several veterinary students, and myriad number of plates and pins.
Once she was recovered enough to go home, she was discharged to her owners and they were given strict instructions to keep potty breaks short, to keep her on-leash when outdoors at all times, and restrict her activity during the many weeks it would take her to fully heal. This was before the days of trazodone and other effective medications that help keep animals calm and decrease problems in the post operative period, so the owners were left to do the best they could.
Well, their efforts failed.
Within a week of discharge, this spunky spaniel slipped past her humans and bolted after a rabbit, which dislodged the plates, screws and pins that were holding her pelvis in place. Ooowweeee!!!!!! She landed right back in the hospital and the surgeons tried to repair what could be repaired.
So why do animals continue to remain active when injured or in pain?
A few concepts of learning and behavior science can help explain this. The first is the Matching Law, which states that when given the choice, animals will engage in whatever behavior offers the highest reinforcement or has the strongest reinforcement history—i.e. behavior matches reinforcement.
In learning science, a reinforcer is something that strengthens a behavior if it’s delivered after the behavior occurs. In other words, when animals do something that leads to a good result, they're likely to do it again. This happens in two main ways: either they get something they perceive as desirable (like food or the opportunity to chase), or they avoid something they perceive as unpleasant (like a threat or pain). This is how animals naturally learn which behaviors to repeat.
That means if a dog has a stronger reinforcement history for chasing squirrels (it is super fun!)2 than they do remaining still in the presence of squirrels, they’re going to choose chasing. Extreme pain may tip the scales towards remaining still/not chasing, but spunky spaniels and pro athletes show us how powerful reinforcers can be, even in the presence of pain.
To further complicate matters, behaviors can become more reinforcing if the opportunity to engage in them is restricted,3 which means your dog or cat might want to be active even MORE if you’ve restricted their opportunities for activity. Don’t mistake their zest for activity as evidence their pain has resolved—it could just be evidence they enjoy running around and haven’t had the chance to do so for a while.
The examples provided thus far are of animals experiencing acute pain. I suspect that chronic pain has an even weaker effect on highly reinforced behaviors—at least that’s true for me. I regularly experience mild chronic pain. I’m middle-aged, so I’ve recently been confronted with the reality that I can hurt myself just getting out of bed, and I have scoliosis which puts excessive strain on the muscles of my back and hips. I also have tendinosis in my left elbow and wrist, a repetitive use injury from carrying a big heavy camera for hours on end. Does that stop me from continuing to carry my camera or lying down on concrete to photograph birds?
No, it absolutely does not.
I only leave my camera at home when I’m having an acute flare up. While some might justifiably call me foolish for this, my behavior is a good example of temporal discounting. Temporal discounting describes how the strength or value of a reinforcer (e.g. feeling better) decreases as the delay increases. Feeling better from leaving my camera at home is a consequence too far off in the future. The birds are here just waiting to have their pictures taken right now.
I’m not alone, as temporal discounting is responsible for a lot of failed efforts to eat healthier, cut out alcohol, or exercise more. And while temporal discounting has been studied in dogs, and some dogs show a greater ability to withstand a delay of reinforcement than others, I’m not sure they’re thinking “I’m gonna pay for this later” as they gleefully chase after that squirrel.
Adding emotions into the mix introduces further complications
Fear and anxiety have their own impacts on behavior, and most often increase behaviors that protect an animal from a threat. That means if your painful pup perceives other people and dogs as threatening, they’ll continue to run vigorously along your fence line while barking and growling “GO AWAY!” at passersby, or continue lunging and barking at approaching strangers. They may even increase their efforts in these behaviors because fear amplifies pain and pain amplifies fear. It’s a vicious cycle.
Where pain might show up
When an animal is experiencing pain you’re probably more likely to see a decrease in behaviors that have a weaker reinforcement history and an increase in behaviors that allow the animal to avoid pain instead. Let’s say you see your dog or cat on the furniture and you want them to get off. Even if you’ve trained them to get off furniture when asked,4 if your pet has pain remaining on that nice cozy couch and avoiding uncomfortable movements is going to win over getting up. This is one area where we see dogs and cats escalate to aggression to get us to back off—we humans tend to force the issue, either grabbing them and pulling them off furniture or picking them up, which increases the dog or cat’s discomfort, frightens them, and causes them to respond defensively.
In both cats and dogs we can also see pain result in an increase in house soiling. If your cat has to navigate a set of stairs or perform kitty acrobatics to get to their litter box,5 their efforts to use your preferred litter box may decrease as they try to avoid discomfort. That conveniently placed soft bathroom rug, clean tile floor, or fresh pile of laundry is going to start looking like a much better option.
Should you withhold pain medication to make sure your pet isn’t too active after an injury or surgery?
Absolutely not. Pain is an unpleasant emotional and sensory experience that negatively effects quality of life and leads to many poor outcomes including impaired healing, immunosuppression and worsening mental health. All veterinarians have a moral and ethical duty to decrease suffering from pain as best we can. In fact, when new pain therapeutics are being studied, they are not compared to placebo (something we know won’t have an effect), they’re compared to the current gold standard. Giving a placebo in these studies would be unethical because we know those animals will suffer and have worse outcomes without treatment.
Rather than withholding pain medications to force reduction in activity (which we’ve already seen doesn’t work), we need to treat pain when we find it, and work together to find effective solutions to manage your dog or cat’s activity while they heal. And we need to avoid assumptions about what animals might do and not do when in pain, acknowledging it’s impact on behavior is quite complicated.
What did you used to believe about pain in animals that you’ve discovered is false or questionable? Let us know in the comments, or share anything else that’s coming up for you.
Insightful Animals is operated by me, 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 day-to-day, I consult directly with pet parents and veterinarians on a range of behavior problems in dogs and cats. You can support this publication and help keep it free for everyone by becoming a paid subscriber.
Sorry, Pipit and Towhee, but it’s true
Chasing, even without catching, is reinforcing for many dogs and cats
This is referred to in the scientific literature as response-deprivation or response-restriction theory
Many people don’t train this behavior in cats at all, and if they do train it in dogs, don’t reinforce it well enough
It can be challenging for cats to get into top-entry litter box or those with high sides or steps
I really enjoyed reading this. The concepts are explained in an easy-to-understand way with great examples. I especially like the post-op section.
Love the article. And Kelly, your bird pictures are amazing!