Screening and Therapeutic Efficacy of Topical Agents for Teat Hyperkeratosis in Dairy Cows

In dairy cows, teat keratinization occurs where keratinized tissue rings form around teat tips (opening). Manifesting as skin damage in mechanically milked dairy cows, keratinization presents as dry, rough, pale, or milky-white keratinous protrusions around teat orifices and progresses via the combined effects of mechanical stress, management practices, host genetics, environmental influences, and nutritional metabolism. The teat hole is the first physiological barrier protecting the mammary glands from external pathogen invasion. Most mastitis cases are caused by pathogens invading the mammary tissues from the teat end, thereby significantly impacting mammary gland health. Thus, there are no safe, effective, economical, and standardized treatment protocols for terminal teat hyperkeratosis in dairy cows. To address this, we treated keratinization lesions using pharmacological interventions and evaluated their efficacy in 91 cows at a large commercial dairy farm in Heilongjiang Province. Urea ointment, salicylic acid ointment, and 5% azelaic acid acne cream exerted therapeutic or alleviating effects toward teat keratosis, whereas retinoic acid ointment demonstrated poor therapeutic efficacy. In a three-daily application regimen, the optimal treating dose was 0.3 g. These findings provide a scientific basis for the clinical management of hyperkeratosis in large-scale dairy farms and the development of related veterinary therapeutics.