Use of infrared thermography to detect inflammation caused by contaminated growth promotant ear implants in cattle.
OBJECTIVE
To compare the infrared thermographic appearance of bovine ears that had received contaminated growth promotant implants with ears that had received clean implants and ears without implants.


METHODS
Prospective study.


METHODS
32 yearling crossbred beef steers with a mean weight of 322 kg (708 lbs).


METHODS
Contaminated (n = 16) and clean (16) implants were placed in the ears of feedlot cattle. Nonimplanted (n = 32) ears served as a within-animal control for thermographic comparisons. Images of rostral and caudal surfaces were obtained during a 21-day period, using an infrared thermal imaging radiometer. Repeated measures ANOVA was used to determine the relationship between mean temperature in a zone on the rostral surface of the ear and at 3 locations (proximal, middle, distal) on the caudal surface of the ear (response variables) with treatment (ears with contaminated implants or clean implants vs control ears with no implants), time (repeated day of measurement), and interactions among these variables.


RESULTS
Significant temperature differences existed between ears with contaminated implants and control ears. Temperatures for ears with clean implants were significantly higher than control ears on day 2. At low ambient temperatures when the ears became wet, a greater temperature contrast was detected between ears with contaminated implants and control ears.


CONCLUSIONS
Thermal imaging of the ears of feedlot cattle is a noninvasive diagnostic tool that can be used to identify cattle with abscesses caused by contaminated growth-promotant implants.
Spire
M F
MF
Food Animal Health and Management Center, College of Veterinary Medicine, Kansas State University, Manhattan 66506, USA.
Drouillard
J S
JS
Galland
J C
JC
Sargeant
J M
JM
D000287:Administration, Topical; D045930:Anabolic Agents / Q000008:administration & dosage; D000818:Animals; D000891:Anti-Infective Agents, Local / Q000008:administration & dosage / Q000627:therapeutic use; D002417:Cattle; D002418:Cattle Diseases / Q000175:diagnosis* / Q000209:etiology / Q000517:prevention & control; D002710:Chlorhexidine / Q000008:administration & dosage / Q000627:therapeutic use; D004343:Drug Implants / Q000009:adverse effects*; D004958:Estradiol / Q000008:administration & dosage / Q000031:analogs & derivatives; D006133:Growth Substances / Q000008:administration & dosage; D008297:Male; D010032:Otitis Externa / Q000175:diagnosis / Q000209:etiology / Q000517:prevention & control / Q000662:veterinary*; D011446:Prospective Studies; D013817:Thermography / Q000662:veterinary*; D014204:Trenbolone Acetate / Q000008:administration & dosage / Q000031:analogs & derivatives
D045930:Anabolic Agents; D000891:Anti-Infective Agents, Local; D004343:Drug Implants; D006133:Growth Substances; C074283:estradiol 3-benzoate; D004958:Estradiol; D002710:Chlorhexidine; D014204:Trenbolone Acetate