I'm going to be playing a lupus with a focus on Bite attacks in an upcoming game. I'm aware of a few totems and gifts that enhance natural attacks, but I'm looking for fetishes to help out.
Quite complicated, since most fetishes that help combat are weapons, shileds and armour (things you use in humanesque form) not really helpful for lupusesque forms. But there are a few.
I think the best suited should be scar fetishes (a fetish you create on your scar).
For example, you have body of scars (I find it through the net, but it seems to be in the book 'hammer and klaive'):
Body of Scars
Background Points: 5
Gnosis Rating: 7
Spirit: A plant or rabbit spirit
Appearance: This fetish is bound into a Scar that the Garou has received that reduced her below Incapacitation (thus resulting from a Rage Heal).
Effect: When activated the scar begins to slowly grow, spreading out over the user’s body. If a blow strikes the bearer, the scar will immediately surface there. The hard scar tissue protects the body, granting +2 traits for the purposes of soaking. In addition the fetish provides 3 additional health level that may be healed. This fetish may not be stacked with gifts or fetishes that provide similar effects (such as Troll Skin). Source
As always, fetish are not set in stone and you could create your own (if Mages can do it, Werewolves should be way more able to do so). So you can talk to your storyteller and build something that both of you are happy with. I am aware that it is not a very helpful answer, since this specific example doesn't help with bite manouvers. You can also check leaf armor or combat harness to see other fetishes that help combat that can be used in lupus form.
Actually, if you convince your storyteller that your combat harness is for hispo form (for some reason) I think it could easily be the best fetish to help you (since it could add dex/str).
I think you coming to this from wrong perspective: you are a wolf, you don't need artificial, "human" fight enhancing tools - Gaia gave you your jaws and thats enough. You have natural contact with spirits, but you treat them as mentors and guides rather than tools - again, thats human thinking. Lets look at Red Talons, the lupus only tribe:
Red Talon fetishes are often of simple make, perhaps a piece of antler or a rock that just "felt right." Rarely they use fragments of human fabrication, if only because it's more frightening that way. Because Red Talons feel that Gaia gave them all the weaponry they need, and often prefer the Hispo form for fighting, the use of fetish weapons is fairly uncommon, and many Red Talons deride the practice. (Needless to say, Red Talons do not have the requisite skills or technology to forge silver into klaives.) Predator spirits are so rare in these times that Red Talons prefer to bind prey spirits into talens and fetishes if at all possible. (source)
If you are coming from more human-oriented tribe then there could be some more possibilities - I wouldn't be surprised if Shadow Lord or Uktena had a Pain Spirit imbued somehow i.e. as a tattoo on their face to add extra point of damage, and there are of course infamous Cyber Wolves - but as a general rule I'd say you are fairly limited.