Study suggests ocular thermography may aid canine temperature screening

Ocular thermography may be closer to a practical screening tool in dogs than many clinicians have assumed. In a new study tied to the American Journal of Veterinary Research, investigators reported that infrared eye temperature and rectal thermometry showed similar diagnostic performance for detecting abnormal body temperature in dogs in a shelter setting. But the headline comes with an important qualifier: neither test was especially sensitive, and the value of both depended heavily on the clinician’s baseline suspicion that the dog’s core temperature was abnormal. (assets-eu.researchsquare.com)

That framing matters because rectal temperature has long been treated as the clinical reference point, even though it’s not always easy to obtain quickly, safely, or with minimal stress. Earlier literature has generally supported rectal thermometry as the standard in canine practice, while noting interest in alternatives such as ocular, auricular, and axillary measurements. A 2019 review concluded that rectal thermometry remained the most reliable standard in clinical veterinary medicine, and a 2016 Frontiers study found ocular temperature related to rectal temperature but with lower accuracy than ear measurements in resting dogs. (pmc.ncbi.nlm.nih.gov)

The new work takes a different methodological approach. Rather than benchmarking eye temperature against rectal temperature as though rectal readings were error-free, the authors used a Bayesian latent-class model to estimate the sensitivity and specificity of both tests without a perfect gold standard. The study included 238 visit-level observations from 121 dogs, split into puppy and adult subpopulations, with repeated measures accounted for at the dog level. Posterior median estimates were 0.40 sensitivity and 0.94 specificity for eye temperature, compared with 0.32 sensitivity and 0.99 specificity for rectal temperature. The authors’ bottom line was that ocular thermography and rectal thermometry had similar diagnostic performance, especially in ruling in concern when a reading was abnormal, while normal readings were less informative. (assets-eu.researchsquare.com)

This paper also builds on a broader line of work from the same Mississippi State group. In a separate AJVR study, the researchers estimated a reference interval for eye temperature in 78 apparently healthy shelter dogs using a robust statistical method with bootstrap-derived 90% CIs. They reported a central 95% reference interval of 35.0 to 38.5 °C for eye temperature, compared with 37.5 to 39.7 °C for rectal temperature. That is a useful practical addition because it gives clinicians population-based screening limits for ocular thermography rather than forcing them to borrow rectal cutoffs for a different measurement site. The authors emphasized that temperatures outside those ranges justify individual medical evaluation, while also noting that the rectal interval mainly served to confirm that the study population was clinically normal rather than to redefine established veterinary standards.

This paper also builds on a broader line of work from the same Mississippi State group. In a March 2026 report, the researchers found that eye temperature in apparently healthy shelter dogs was associated with rectal temperature but was not interchangeable with it, and they suggested ocular thermography might help triage dogs for confirmatory rectal thermometry when rapid, low-handling screening is needed. In a Frontiers in Veterinary Science paper published May 26, 2026, the group further reported that eye temperature was significantly associated with rectal temperature, age group, and repeated measurement conditions, reinforcing that device handling and environmental context can influence readings. (scholarsjunction.msstate.edu)

There doesn’t appear to be much outside commentary yet on this specific AJVR study, but the surrounding literature points in a consistent direction: infrared thermography is promising as an adjunct, not a drop-in replacement. Prior canine studies have highlighted the appeal of rapid, noncontact temperature assessment, particularly for animals that are stressed, difficult to handle, or being screened in groups. At the same time, published reviews have cautioned that alternate sites require their own validated reference intervals and can be affected by physiology, environment, and technique. The new eye-temperature reference interval study strengthens that point by showing that normal ocular readings sit well below normal rectal readings in the same shelter population. (pmc.ncbi.nlm.nih.gov)

Why it matters: For veterinary teams, especially in shelters, emergency intake, or high-throughput settings, this study supports a more nuanced use of temperature data. If ocular thermography can identify some dogs with abnormal temperature without immediate restraint, it may improve low-stress triage and help staff decide which patients need prompt confirmatory testing. But the study also argues against overinterpreting a normal eye temperature, or even a normal rectal temperature, in isolation when clinical suspicion remains high. In practice, that means ocular thermography may be most useful as part of a decision framework that includes signalment, behavior, environment, presenting complaint, and hands-on exam findings. And if clinics do use it, the newer AJVR reference-interval data suggest they should apply eye-specific thresholds rather than rectal norms. (assets-eu.researchsquare.com)

The shelter setting is another key limitation. These dogs were kennel-housed, measurements were designed to simulate low-stress screening, and dogs with clinical ocular disease were excluded. That makes the findings relevant to shelter medicine and triage workflows, but not automatically generalizable to referral hospitals, febrile inpatients, brachycephalic dogs, perioperative patients, or animals with ocular pathology. The reference-interval work was also based on apparently healthy shelter dogs studied over a 2-month period, so broader validation across breeds, environments, and devices will still matter before any ocular cutoff is treated as widely applicable. Broader validation, including in clearly sick populations and across device types, will likely determine whether ocular thermography remains a niche screening aid or becomes a more routine part of canine temperature assessment. (assets-eu.researchsquare.com)

What to watch: The next step is external validation: peer-reviewed publication status in AJVR, replication in general practice and emergency populations, and clearer protocols for when an ocular reading should trigger confirmatory rectal thermometry or additional workup. It will also be worth watching whether the proposed 35.0 to 38.5 °C eye-temperature reference interval holds up in other canine populations or needs adjustment by setting, device, or patient characteristics. (assets-eu.researchsquare.com)