This is the first time I’ve heard of cavus. According to one site:
Non-Surgical Treatment
Non-surgical treatment of cavus foot may include one or more of the following options:
- Orthotic devices. Custom orthotic devices that fit into the shoe can be beneficial because they provide stability and cushioning to the foot.
– Shoe modifications. High-topped shoes support the ankle, and shoes with heels a little wider on the bottom add stability.
– Bracing. The surgeon may recommend a brace to help keep the foot and ankle stable. Bracing is also useful in managing foot drop.
Source
If these aren’t options, I’ll cast a second vote for checking out Merrell. I have a high arch, and this brand is just about the only one I wear now. Many of their styles come with a very high arch support and are very cushioned. Their hiking boots offer a selection that go above the ankles, providing additional support. The Merrelll site linked has a store location site feature in the top right-hand corner. It would be worth the effort to find one and check them out.