1. Avoid wearing the collar/lead on the rainiest of days. Leather thrives in dry environments.
2. Treat the leather 1-2 times a year using a leather conditioner, and make sure that the leather has dried up properly before using the collar for your dog.
3. If the collar gets a stain or two, remove with a damp cloth and allow the leather to dry.
Still there? Use a leather stain remover and follow up with leather conditioner for best results.