ISO is NOT a good name for a dog. ISO stands for International Standards Organization, an organization that issues thousands of industrial standards, the vast majority of which have nothing whatsoever to do with photography. The standards that the most non-photographer people have heard of are ISO 9000:2015 and ISO 9001:2015 that focus on quality control systems in general industry. Only four (4) of those thousands of standards pertain to photography and film or sensor speed; ISO 5800:2003, ISO 6-1993, ISO 2240:2003 and ISO 12232:2006.
If I heard you call a dog Iso and I was not a photographer, the first thing that would probably come to mind is ISO 9000, not film speed and its relation to photography.
what gender? pixel seems like a good name for a female; iso or flash strke me as great names for a male dog. With a retriever, maybe something that works with chasing the light.