Evaluating the effects of USDA organic approved topical treatments on sole ulcers

Objective

Sole ulcers are caused by a failure of the suspensory apparatus of the third phalanx within the claw horn capsule, and unbalanced weight bearing that leads to contusion and exposure of the underlying corium. Although subclinical lesions may cause little to no discomfort, clinical lesions often result in severe pain and lameness. Clinical sole ulcers require careful corrective trimming and a block applied to the healthy claw. Recovery may be prolonged and result in reduced longevity of animals affected. Management of these cases on U.S. Department of Agriculture (USDA) certified organic dairy operations requires the use of non-antibiotic therapies, most of which have not been evaluated in controlled studies. The purpose of this prospective randomized clinical trial was to determine if the application of non-antibiotic alternatives would improve healing as evidenced by a more rapid re-epithelization of lesions and a decrease in locomotion score for animals with a clinical sole ulcer.

Materials and methods

One hundred and seventy-three lactating dairy cows with sole ulcer lesions were enrolled between April of 2018 and December of 2020. Treatment outcomes were recorded on D0, 7, 14, 28, 56, and 112 and evaluation criteria included the locomotion score prior to trimming, presence of granulation tissue, and the presence of new epithelium. Enrolled animals were randomized and grouped into one of the five following topical treatments: a) copper sulfate, b) seven percent iodine tincture, c) hydrogen peroxide, d) honey, or e) no treatment. All sole ulcer lesions were lightly wrapped with a bandage following corrective trimming, application of a block to the healthy claw, and the topical treatment (if any) was applied. Treatments were applied on D 0, 7, and 14. Mixed linear models were used for: a) absolute locomotion score at each observation day, and b) change in locomotion score from the previous observation. Full-factorial models of treatment * day effect were explored. Cox proportional hazards regression for time-to-recovery (defined as days to locomotion score = 1 and no granulation tissue, or else right-censoring on or before D112) also was deployed. [...]