There are many topical products available but very few have strong scientific evidence to justify their use. Antibiotics, such as tetracycline have been popular because these products kill the bacteria responsible for digital dermatitis (DD) lesions. The research is most thorough on tetracycline treatment of DD lesions, suggesting that 2 g of tetracycline 1000 (or 8 g of tetracycline 250) is sufficient to successfully treat M2 lesions (defined as an acute, ulcerative, reddish, often painful lesion ≥ 2 cm in diameter). Tetracycline is effective and safe to use when used at the correct dose, on the correct type of lesion, and limiting the number of cows treated at the same time. However, its use is extra-label, and it represents a risk for milk residues. Therefore, a protocol must be developed with your veterinarian that includes milk withdrawal intervals. Other than tetracycline, scientific evidence is lacking on alternative products in terms of the correct dose and resulting milk residues, making recommendations on the vast number of alternative topical products difficult.
There is an approved product available through your veterinarian indicated for treatment of DD in Canada that has no milk or meat withdrawal when used according to the label recommendations. If you are interested in trying one of the many non-antibiotic options available, choose something that is not too caustic or corrosive as this will damage the skin and make healing more difficult. Keep in mind, many of these non-antibiotic options have limited (if any) scientific evidence on effectiveness, dosage, or residues, which may impact their overall success. A complete DD control program should focus on prevention of DD with proper foot bath design and protocols that will limit the number of lesions that need to be treated.
– Casey Jacobs, PhD, Animal Care Specialist, More Than Just Feed