This is a very tough injury. Do all you can. Get him injected and do the shock wave series. I am almost at the end of rehab for Proximal Suspensory Desmitis and I did not know how hard it would be to heal. (Sounds like the same as your horse without the tear.) Since my horse did not have a tear, he did not have to have stall rest. Monitor and keep record of the ultra sound reports. Between 3 and 6 months my horse still had thickening of the ligament and there was still some inflammation. His ligament measured 1.7 square cm where the other hind was a very normal 1.5 square cm. At this point, I really freaked out. I figured that if he was still in pain and still had inflammation, the best way to get rid of it would be ice. I bought ice boots from Dover for $75. Every morning he stood in the ice boots for 20 minutes and then I wrapped him in a cold poultice for the day. In the early evening, I cold hosed the poultice off and stood him in the ice boots again for another 20 minutes. I did this for a few weeks and every ride (20 minutes walk with some trot sets) got better and better. I went to the clinic 3 weeks after the ice/poultice routine. After the initial flexions, the vet actually said, “Why are we here?” I was so happy! When the ultrasound vet did her thing she said his ligament looked great. I asked for the measurements. 1.5 square cm and NO inflammation! I felt like it was a miracle. I did end up finding out that he now has some inflammation in the diagonal front leg from compensating for the hind all this time. So, I have a minor setback. It looks like three more months of ice, poultice and wrapping - of walk and trot, and then another ultrasound at 90 days. If everything is good, I’ll start to add canter. If things go as planned, it will be one full year start to finish. The hind suspensory injuries are so much harder than the front. Get him injected with whatever your vet suggests and do shock wave and all the rehab you can. At this point, I’ve decided to buy a Game Ready machine for rehab and prevention. I never want to go through this again.