Submitted to: Research Workers in Animal Diseases Conference Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: 8/18/2003
Publication Date: 10/12/2003
Citation: EICHER, S.D., PATTERSON, J.A., WILCOX, C.S., JOHNSON, T.A., SCHUTZ, M.M., JOHNSON, T.R. THERMAL IMAGING INDICATIONS OF ELEVATED BODY TEMPERATURES DURING A SALMONELLA DUBLIN CHALLENGE. RESEARCH WORKERS IN ANIMAL DISEASES CONFERENCE PROCEEDINGS. 2003. P. 52.
Technical Abstract: Salmonella dublin is a frequent cause of morbidity and mortality in neonatal dairy calves following transport. Following stressors such as transport, elevated temperatures are an indication of acute stress or disease. To unobtrusively get an animal's temperature would be beneficial for many research projects and for producers wanting to quickly assess the condition of stressed calves. The objectives of this study were 1) to determine a dose of Salmonella dublin that was infective, but not lethal and 2) to determine the validity of using thermal photography to assess body temperatures during that infection. Three-week-old Holstein bull calves (with access to hay and grain) were assigned to one of three doses of Salmonella dublin. At 0800 on experimental day 1, nine calves were given an oral dose of 106, 107, or 108 cfu of Salmonella Dublin, followed with 10 ml of bicarbonate buffer. Rectal temperatures were recorded hourly for the next 72 h. Thermal images were taken hourly between 0800 and 1600 on d 1, 2, and 3. Thermal images were recorded using a FLIR® Thermal Camera, 1.5 m from the calf to include the full face of each calf. Temperatures from the ear, nose, and eye were compared with the rectal temperatures. Eye temperature had the least variability and was used in subsequent analysis. Fecal scores, ocular and nasal discharges, and attitude scores were recorded twice daily. By day 3, the high dose calves had higher rectal temperatures than their own baseline and the two other treatments (P < 0.05). The fecal scores of those calves also increased (indicating more scouring) for the highest dose compared to the other two doses by day 3 (P < 0.05). A regression analysis of the rectal and thermal-image temperatures showed an R2=0.42 (P < .001) and correlation analysis resulted in a correlation coefficient of .65 (P < 0 .05). These results show that the highest dose (108 cfu) was an adequate dose to infect 3-wk-old calves that are eating grain and hay in addition to a milk replacer diet and that thermal imaging has potential for following increased body temperature.