Replied by Mama To Many (Tennessee) on 02/09/2016
You can always dilute the vinegar more. 1/4 vinegar with 3/4 water. But a cat will always try and get off what he thinks is offensive, so even that he may try to get off. And it is quite safe internally.
Apple Cider Vinegar has been used in many, many applications for pets and found to be quite safe.
~Mama to Many~