Looking for recommendations on a CRM where the concern isn’t sales funnels, but referral management.

TL;DR – a vet clinic looking to manage referring doctors and set up communication with them, so there isn't really a sales cycle with closing stages, but wanting to enter LTV (revenue from their referred patients) and then set up communication flows (eg: thank them for a referral, handle contacts, view last time they sent a referral, etc).

I imagine most can handle workflows like this, but all sales related software are heavy on the opportunity/funnel use case which isn't quite a fit here.

As long as there is an API to sync data in/out, then we are good on the integration side.