Most small leaks originate where the horn meets the base of the mug. Horn is natural and wants to expand/contract while the base is more rigid and tends to not want to move at all. When there are variations in temperature and/or pressure, this can cause the horn to expand/contract and “move away” from the base which in turn can ultimately leads to leaks. Fortunately, there is a simple fix. Nail hardener or generic superglue works best – both bond well and are safe to use once cured. Find the area where the leak is coming from by adding water. Once the leak is identified, apply some nail hardener/glue to affected area on the outside On the inside, do the same. You may need to use a Precision Applicator if you have huge paws and cannot reach inside the mug/horn. Let the glue cure for a couple of hours or use a UV light to speed up the process. Sand down the excess with fine grit sandpaper until smooth. Good as new! Click here for the video on YouTube.