On canines the claws are part of the tail mesh an on the felines it's the mane mesh.
To get them to work for BOTH, you must download BOTH the canine and feline claw meshes from Tigg's original thread~
Once both .zips are downloaded, extract/unzip them into C: >>> Feralheart >> media > models and click replace.
Then, the claws shall work. :3 Same with any new mesh really. Also, they aren't just added to presets. They will always be on your char as long as it has a tail (for canines) and a mane (for felines), otherwise, they won't show up.
When you make a preset with the claws, they tend to not color in for me all the time, I'm pretty sure you have to fill the tail tip for them.