A spirit guide may identify his presence in many ways. Perhaps in simpler times in rural situations, the use of an animal image was best. Anyway, it was common for people to recognise a member of the animal kingdom as a spirit that would guide them in the ways of nature. How does that fit now with nearly everyone living in the city? The spirit guide will find a way.
A spirit guide is an angel with the role of a guide to help you remember the objectives that you accepted before you were incarnated as a human on this Earth. These angels seem not to be assigned to you for your life. A spirit guide may be attracted to you because you may be at a point in life that interests them. Perhaps, you are at a decision point that will profoundly affect the rest of your life. A spirit guide will not force himself upon you, but will give you small hints or nudges to point out alternatives. Ask one for guidance, and you will surely receive it. Asking an angel for help brings them great joy. They have waited all your life for you to begin to ask. Angels are not allowed to interfere with your life because we live on a planet of free choice. But the angel can create situations that start you thinking. Then he will step back and let you do what you wish.
You can assign a name to a spirit guide or ask "Tell me your name." Right now, ask your spirit guide to tell you his name, or give him a name that you like. Angels do not have a gender, but we may call them "he" or "she", whichever we are most comfortable. Say (out loud) "I am open to the guidance of my angels. I request your help." Then say "Thank you." Do not say "Please." This request will change your life forever. In my experience, as I am about to take an action, I will get a thought in my head that I know is not mine. I have the free will to follow that thought, or not. I exercise that free will many times. Say thank you each time that you realise the guidance. I sometimes say thank you, but no thank you. Then sometimes later, I would wish I had listened more carefully.