Try to find a vet that does Chiro and acupuncture.  You'd be surprised at the results.  Also, you can try a company called THE (Total Health Enhancements).  I've used them for various injuries to our dogs (labs) and my horses.  They have a product called NutraWound that helps with tissue damage and what not.  https://totalhealthenhance.com/equine/products/?route=product/product&path=59&product_id=61  Call the owner Bob Fogli at the number on the website and he can tell you if any of his products will help or not.  He's honest and straight forward and will tell you if something will be useful or not.  They are geared toward humans and horses but he's done special mixes for my labs in the past when we've needed them.