Eye thermography performs similarly to rectal temperature in dogs
Bottom line
Version 1 — Brief
A new American Journal of Veterinary Research study suggests ocular thermography may perform about as well as rectal thermometry for detecting abnormal body temperature in dogs, at least in a shelter population without a gold-standard core temperature measure. In the study, researchers from Mississippi State University analyzed 238 visit-level observations from 121 shelter dogs using a hierarchical Bayesian latent-class model. Posterior median estimates showed similar performance for eye temperature and rectal temperature, with both tests showing high specificity but modest sensitivity: eye temperature sensitivity was 0.40 and specificity 0.94, while rectal temperature sensitivity was 0.32 and specificity 0.99. The authors concluded that abnormal readings from either method can be informative, but normal readings add little beyond the clinician’s pre-test judgment. (assets-eu.researchsquare.com)
Why it matters: For veterinary teams, the finding doesn’t mean ocular thermography is ready to replace rectal thermometry. It does suggest a non-contact eye scan could have value as a low-handling screening tool, especially in shelters, triage, or dogs that are difficult to restrain. But the same research group also reported that the thermal camera used in related field work showed time-dependent measurement drift, and that eye temperature was influenced by age and repeated measurements, reinforcing that device validation and clinical context matter. (frontiersin.org)
What to watch: Watch for follow-up studies in broader clinical populations, especially dogs with more clearly abnormal temperatures and studies using validated, drift-tested devices. (frontiersin.org)
Key facts
- Study type
- Single-shelter observational study
- Journal
- American Journal of Veterinary Research
- Population
- 121 shelter dogs
- Observations
- 238 visit-level observations
- Method
- Hierarchical Bayesian latent-class model
- Eye temperature performance
- Sensitivity 0.40, specificity 0.94
- Rectal temperature performance
- Sensitivity 0.32, specificity 0.99
- Main takeaway
- Abnormal readings from either method can be informative, but normal readings add little beyond clinical judgment
Version 2 — Full analysis
A new study in the American Journal of Veterinary Research adds nuance to a familiar clinical assumption: rectal temperature may be the standard vital sign in dogs, but it didn’t clearly outperform ocular thermography in this shelter-based analysis. Using 238 visit-level observations from 121 dogs, investigators reported similar diagnostic performance for eye temperature and rectal temperature when estimating whether a dog’s core temperature was abnormal. Both methods were highly specific, but neither was especially sensitive, meaning abnormal readings may help flag concern, while normal readings shouldn’t be overinterpreted. (assets-eu.researchsquare.com)
That matters because interest in non-contact temperature tools has been building for years, largely around stress reduction, faster screening, and safer handling. Prior canine studies have shown that infrared measurements can track with rectal temperature, but agreement has been inconsistent across methods and settings. A 2018 dvm360 summary of a JAAHA study, for example, found auricular and axillary temperatures were poor predictors of rectal temperature in healthy dogs, underscoring how hard it has been to find a practical substitute for rectal readings in everyday care. (dvm360.com)
In the new AJVR paper, the authors used a Bayesian latent-class approach because no perfect gold standard for core temperature was available in the shelter setting. Dogs were divided into puppy and adult subpopulations, and tests were dichotomized using prespecified reference intervals. The model produced posterior median estimates of 0.40 sensitivity and 0.94 specificity for eye temperature, compared with 0.32 sensitivity and 0.99 specificity for rectal temperature. The authors’ core takeaway was practical: if a dog truly has an abnormal core temperature, either test can still miss it, but if the dog’s core temperature is normal, either test is more likely to be correct. (assets-eu.researchsquare.com)
The paper also emphasized that test interpretation depends on pre-test probability, not the number alone. The authors wrote that abnormal readings are informative across a wide range of clinical judgment, while normal readings are not especially informative beyond what the clinician already suspected. Combination rules offered tradeoffs: using an “OR” rule, where either test counts as positive, maximized negative predictive value, while an “AND” rule, where both tests must be positive, improved confidence that an abnormal result was real. (assets-eu.researchsquare.com)
Additional context from the same research group helps explain both the promise and the caution. In a related Frontiers in Veterinary Science study published May 26, 2026, the investigators found that eye temperature was positively associated with rectal temperature in shelter dogs, increasing by an estimated 0.6 °C for every 1 °C increase in rectal temperature. But they also found age-related differences and a progressive decline in serial eye readings that appeared tied to device drift rather than physiology. Their conclusion: ocular thermography may be useful as a noninvasive adjunct, but hardware performance has to be checked before clinicians rely on repeated measurements. (frontiersin.org)
Industry and clinical commentary around non-rectal thermometry has generally landed in a similar place: useful adjunct, not automatic replacement. Older veterinary commentary has repeatedly noted that infrared methods can reduce handling and discomfort, but surface temperature is vulnerable to anatomy, perfusion, coat, humidity, ambient conditions, and operator technique. Even the new Frontiers paper framed ocular thermography as a “restraint-free triage tool,” not a stand-alone diagnostic answer. (frontiersin.org)
Why it matters: For veterinary professionals, this study is less about dethroning rectal thermometry and more about sharpening expectations. In high-throughput or high-stress settings, including shelters, intake, and some urgent triage scenarios, ocular thermography could help teams identify dogs that warrant confirmatory assessment while reducing handling burden for staff and patients. But the modest sensitivity estimates mean a normal eye scan, or even a normal rectal reading in this modeling framework, shouldn’t reassure clinicians too much when the history, exam, or risk context suggests otherwise. The bigger message is that temperature data still need to be interpreted through clinical judgment, and that device quality control may be just as important as the measurement site. (assets-eu.researchsquare.com)
What to watch: The next important step is external validation in general practice, emergency, and referral populations, ideally with dogs spanning a wider range of true hypo- and hyperthermia, plus clearer reporting on device calibration, drift testing, and workflow protocols before ocular thermography can move from promising adjunct to routine vital-sign option. (frontiersin.org)