Effects of stacked wedge pads and chains applied to the forefeet of Tennessee Walking Horses for a five-day period on behavioral and biochemical indicators of pain, stress, and inflammation.

OBJECTIVE To determine the effects of stacked wedge pads and chains applied to the forefeet of Tennessee Walking Horses on behavioral and biochemical indicators of pain, stress, and inflamation. ANIMALS 20 Tennessee Walking Horses. PROCEDURES Horses were randomly assigned to 2 treatment groups: keg shoes (control; n = 10) or stacked wedge pads and exercise with chains (10). Ten days before treatment application, an accelerometer was attached at the left metatarsus of each horse to record daily activity. Horses were exercised for 20 minutes daily, beginning on day -7. On day 0, exercise ceased, the forefeet were trimmed, and the assigned treatment was applied. From days 1 through 5, horses were exercised as before. Blood samples for measurement of plasma cortisol, substance P, and fibrinogen concentrations were collected on days -5, 1, and 5 before and after exercise and every 30 minutes thereafter for 6 hours. RESULTS No significant differences in plasma concentrations of cortisol, substance P, and fibrinogen were detected between groups. Although lying behaviors changed after shoes were applied, these behaviors did not differ significantly between groups. Shoeing appeared to have altered behavior to a greater extent than did the type of treatment applied. CONCLUSIONS AND CLINICAL RELEVANCE Application of stacked wedge pads and chains to the forefeet of horses for a 5-day period as performed in this study evoked no acute or subacute stress or nociceptive response as measured. Although these findings should not be extrapolated to the long-term use of such devices in Tennessee Walking Horses performing the running walk, the data should be considered when making evidence-based decisions relating to animal welfare and the use of stacked wedge pads and chains.