I have done Certificate of Animal Care (1 step up from the course your talking about Caryl), which is like an introduction to Vet Nursing. I found this course really good. It covered all animals, first aid, zoonotic diseses etc. There was a unit standard on fish, not extra in depth ( i ended up knowing more about fish than the teacher did) but still very informative. The Companion Animal Services course is really a course for people who want to go into pet shops etc. For the selling side of the animal world. Hope that helps!