Theses and Dissertations

ORCID

https://orcid.org/0009-0005-1023-0840

Advisor

Smith, David

Committee Member

Shi, Jingyi

Committee Member

Jumper, W. Isaac

Committee Member

Wang, Guiming

Date of Degree

5-15-2026

Original embargo terms

Visible MSU Only 1 year

Document Type

Dissertation - Campus Access Only

Major

Veterinary & Biomedical Science (Population Medicine)

Degree Name

Doctor of Philosophy (Ph.D.)

College

College of Veterinary Medicine

Department

Department of Pathobiology and Population Medicine

Abstract

Infrared thermography (IRT) offers a noninvasive method for estimating body temperature in animals without the stress associated with physical restraint. In canine shelter populations, a rapid, contactless temperature assessment could support early detection of febrile conditions while minimizing handling risk to animals and personnel. The objectives of this dissertation were to: 1) assess the short-term temporal stability and performance of an IRT device under controlled conditions with stability evaluated against manufacturer-stated specifications, 2) evaluate the association between ocular surface temperature and rectal temperature in shelter dogs, 3) establish reference intervals for ocular temperature, and 4) determine the diagnostic performance of ocular temperature measurement using Bayesian latent class analysis (BLCA) in the absence of a perfect gold standard. A preliminary study evaluated whether the IRT device’s temperature readings shifted over short time intervals under controlled conditions to develop standardized measurement protocols. Subsequent field studies in shelter dogs assessed repeatability, covariate effects, and the relationship between ocular and rectal temperatures. Reference intervals for ocular temperature were established and used to classify dogs as having normal or abnormal body temperature (including hyperthermia and hypothermia). Finally, BLCA was applied to estimate sensitivity, specificity, and predictive values of ocular and rectal temperature measurements in classifying dogs according to thermal status. Overall, ocular and rectal temperatures were influenced by both biological and environmental factors in the shelter setting. Under the hierarchical BLCA, ocular thermometry showed moderate sensitivity and high specificity, while rectal thermometry showed similarly high specificity with moderate sensitivity. In practical terms, these tests provide stronger support for ruling in abnormal temperature when positive than for ruling it out when negative, and combined decision rules offer a useful framework for rapid triage. Additional multi-shelter studies with broader environmental variation would help refine thresholds and improve generalizability. This dissertation integrates device validation, epidemiologic study design, and advanced statistical modeling to provide practical, evidence-based recommendations for implementing IRT screening in shelter environments.

Sponsorship (Optional)

Funded by USDA ARS #58-6064-3-017

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