Currently, both reptile and reptilian are used as species tags. Canine is used as a species tag instead of canis, equine is used as a species tag when it should be equus, etc. Change the species tag canine (of or relating to the genus Canis) to a regular tag implied by the species tag Canis? e.g.

Species tag: Canis
Implies
Tag: Canine

Species tag: Equus
Implies
Tag: Equine

Species tag: Reptile/Reptilia
Implies
Reptilian

etc.

We use canine, equine, etc. because they are easier to read for the average furry, plus are more searchable terms.

I know this in general but they are descriptive terms rather than an actual species term, and if this was implemented, "canine" could be used as a tag for anything with canine features, while canis could be used for creatures that are obviously feral full canines. The species tag would naturally imply the canine tag, so the same search results would come up and you would only have to search canis to get the results you want now, or search canine rather than every dog related tag that might exist.

123easy said:
We use canine, equine, etc. because they are easier to read for the average furry, plus are more searchable terms.

This. We aren't Marriam-Webster.com - if you want canis to make searching for feral canines better, just search feral canine. Done and done. Unnecessary change.