Low-cost thermometer identifies cows with poor hoof health
medwireNews: A low-cost hand-held infrared thermometer can successfully identify cows with potentially treatable hoof lesions, report researchers in the Veterinary Record.
Cows with conditions ranging from white line disease to toe necrosis had significantly higher hind foot temperatures than cows without any hoof condition, show the study results.
The finding indicates that such a tool "could be used as part of a herd-level control strategy to prioritise the treatment of individuals within a herd for infectious conditions," write the authors.
Since treating cows requires restraining them and lifting their feet, a screening method to identify those most likely to benefit from further investigation or treatment would be valuable, suggest David Main (University of Bristol, Langford, UK) and colleagues.
The team examined both hind feet of 143 cows in October 2011 from six separate dairy herds in Somerset, UK, and identified 167 lesions on 139 feet. The most common cause of lesions was white line disease, accounting for 45 of them, followed by sole ulcers at 31 lesions, digital dermatitis, at 23 lesions, sole separation, at 16 lesions, and sand crack, at 14 lesions. Punctures, bruising, and toe necrosis were among other conditions identified.
Temperatures of feet without lesions ranged from 17.2°C to 28.7°C, while those of feet with lesions ranged between 21.2°C and 37.3°C. Indeed, the mean temperature of feet with lesions was significantly higher than that for feet without, at 26.8°C versus 23.6°C.
There was significant variation between farms in foot temperatures with and without lesions, however, leading the researchers to suggest that the thermometer method of detecting lesions should be limited to one herd rather than multiple herds.
After accounting for potential confounders, the team observed that temperatures varied significantly according to lesion type and were significantly different between the cows' left and right feet.
Using a threshold temperature of 25.25°C for the maximum temperature across both hind feet for each cow, the sensitivity and specificity of foot temperature to identify the presence of any type of lesion was 78%, report Main and co-investigators.
The team acknowledges that factors such as ambient temperature and cows' activity levels may have affected their baseline hoof temperatures, therefore further work to "identify optimum comparative measures" is needed.
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By Sarah Guy, medwireNews Reporter