From my experience (purely subjective!) animal guides come to you, rather than the other way round. Plus, it seems that you may have many different animal guides opposed to just one or two, that may come to you at various times to help with whatever particular area of life is relevant - while at the same time, they also seem to serve as representations of the different parts of your  self. So, I guess there's a type of internal/external synergy going on.

Having said that, perhaps by voicing your intention to connect with them - via work with plant teachers and meditation etc you open yourself up to connecting with them, sooner or later.