Anyone here building for a "niche" nobody else takes seriously?

I'm launching a pet health app tomorrow, but the part I keep thinking about is the positioning. Every pet app assumes you have a dog or a cat — reptile, bird, and fish keepers get a blank "other" profile and a shrug. So we built the depth those animals actually need (UVB bulb replacement schedules, water parameters, shed cycles) and led with that, even though it's the smaller audience.

The bet: go deep on the underserved group first, earn the community, expand into the mainstream from a differentiated position. The risk: getting boxed in as "the lizard app."

Has anyone here made that trade? Did leading with the niche help or trap you?