Dogs Don't Just Feel Stressed at the Vet. Now We Can See It.

A thermal camera pointed at a dog's eye just confirmed what every tech who has ever held a trembling patient already knew in their gut.

You know the dog. It froze at the scale, wouldn't take the treat you offered, and by the time you got the stethoscope out, its whole body was doing that fine, fast tremble that isn't cold, it's fear. Maybe you told yourself it was just a nervous one, or a bad breed for the vet, or a dog that needed a little more Fear Free coaching from its owner at home. Turns out there was something happening under that dog's skin that no amount of behavior training would have caught on its own.

A research team at the University of Veterinary Sciences Brno in the Czech Republic set out to answer a fairly simple question, whether the stress we watch dogs display in the clinic is actually showing up in their bodies, not just their behavior. Led by Veronika Pokorna alongside Eva Voslarova, Iveta Bedanova, Lucia Kotianova, and Vladimir Vecerek, the team enrolled 96 healthy dogs who were coming in for routine vaccinations and watched them through four stages of a completely ordinary appointment, the waiting room, right before the exam, during it, and after.

They counted twenty one different stress behaviors along the way, the lip licks, the tucked tails, the trembling. But the part that makes this study worth sitting with is what they added on top of the behavior watching. In a subset of 45 of those dogs, the team used an infrared thermal camera to track the surface temperature of the lacrimal caruncle, that small pink patch tucked into the inner corner of a dog's eye. It is packed with blood vessels that respond almost instantly to the sympathetic nervous system, the same system that fires when a body decides it is under threat.

The behavior and the thermal camera told the same story, and they told it independently of each other. Stress behaviors climbed steadily through the visit and peaked hardest during the physical exam itself. So did the temperature around the dogs' eyes. And critically, that eye temperature had nothing to do with the dogs simply running a fever, the researchers checked it against rectal temperature and found no correlation. What the camera was picking up was emotional, not a body running hot for some unrelated reason.

A few other details are worth tucking away for your own patient population. Small dogs, 11 pounds and under, showed noticeably more stress behavior than their larger counterparts. Dogs between two and six years old were more visibly anxious than other age groups, which does not necessarily match the assumption that puppies are the jumpiest patients in the building. And younger dogs, the ones still in their first year, actually ran higher on the thermal readings than older dogs did, a physiologic wrinkle the researchers flag as worth digging into further.

None of this means every practice needs a thermal camera by next quarter. What it means is something quieter and, honestly, more useful, that the instincts a lot of veterinary teams already have about which dogs are struggling are backed by measurable biology, not just a hunch. The dog that looks calm but will not make eye contact may not be fine. The one that goes rigid and still on the table is not being difficult, its body has already made a decision about what kind of moment this is.

The researchers point to acclimation time, minimal restraint, food rewards where appropriate, quieter rooms, and low-stress handling as the practical levers clinics already have, the same tools Fear Free certified practices have been building protocols around for years. This study does not invent new advice so much as it hands the profession something harder to argue with, proof that the small adjustments a good tech makes without thinking about it are doing real physiologic work, not just making a visit feel nicer on the surface.

Source: Pokorna V, Voslarova E, Bedanova I, Kotianova L, Vecerek V. Assessing Canine Stress in a Veterinary Clinic Setting: Behavioral and Thermographic Analysis. Journal of Veterinary Behavior, 2026. Published ahead of print via ScienceDirect.