Can Animals Experience a Placebo Effect?
By Annie Emery
This is a post generated from the companion Podcast https://www.buzzsprout.com/2331476/episodes/19786884
Animals don’t read the label. They don’t know the advertising. So how could a placebo effect happen in a horse, dog, or cat?
It’s actually a really interesting question. Expectations, observations, natural fluctuations, learning, and human-animal interactions can all influence what we believe we’re seeing.
This matters when we evaluate supplements. We want our animals to feel better, but noticing a change is the beginning of the investigation, not necessarily the end.
A Placebo Response Isn’t Automatically a Placebo Effect
A placebo response is any change measured while an animal receives a placebo—the inactive thing being studied. That does not automatically mean the placebo caused the improvement.
Conditions fluctuate. Exercise, daily care, weather, footing, and routines may change. The person measuring the outcome may also interpret things differently.
Then there’s regression toward the mean. We typically start a supplement when a problem is noticeable: the horse is stiff, the dog is uncomfortable, or the cat has stopped jumping onto the bed. An unusually bad period may be followed by something closer to that animal’s normal, whether or not we intervene.
If the animal improves, we might say the product did the thing. But not so fast. We need to look at the bigger picture.
What Does the Research Show?
In a study of dogs with osteoarthritis, owners and veterinarians often thought dogs receiving a placebo had improved, even though objective force-platform measurements did not support that improvement. The perceived improvement became stronger over time.
Research in cats with joint pain also found differences between what owners reported and what activity monitors recorded. It went both ways: owners sometimes reported improvement the monitors did not show, and sometimes missed measurable increases in activity.
This does not mean observations are worthless. A force plate captures a particular part of movement during a brief test. Owners see their animals in their everyday environments. Those observations matter, too.
But when subjective and objective measurements are far apart, we need to take a look.
Your Response Can Affect Your Animal
There’s also a possibility called placebo by proxy.
Imagine you give your horse a calming supplement because you believe it will help. Perhaps you approach with less tension. Your breathing changes. Your hands become quieter. You give the horse more time to process.
The horse might respond to your response. Something real could be happening, even if the substance itself isn’t responsible.
Animals can also learn associations that influence physiological responses. Conscious belief isn’t required. That does not prove a particular supplement works, but it adds another layer to the conversation.
How Can We Evaluate a Supplement?
Translate “I want my horse to feel better” into something concrete.
Create a baseline before starting.
Record specific behaviors and use numbers when possible.
Take photos or videos under similar conditions.
Know when you would reasonably expect a change.
Don’t change 50 things at once.
Keep your veterinarian involved with medical concerns.
Bias isn’t dishonesty, and it doesn’t mean someone is stupid. Everyone is capable of bias.
My job is to help you choose feeds and supplements, understand what to expect, and look at the whole animal. Nutrition programs support veterinary care; they don’t replace it.
Stay curious, keep asking good questions, and be the smartest kids in the class.
Need help? Reach out for help with your dog, cat and horse today
