Background: took my gelding in for regular hock injections in February. Vet found VERY slight lameness in LF. Nerve blocked for navicular and it had no effect. Nerve blocked twice more up the leg and came to find behind the knee took away the lameness. Took Xrays and it appeared he strained his suspensory. No rip or tear. Did an injection, stall rest for 6 weeks, went back for the lameness test and he passed. Cleared to start slowly back to work. About 2 months after that the LF lameness is on and off. Again its extremely SLIGHT! Most people wouldn't tell. He has good days and some bad. He is sound on bute and loves to work! Very solid top 2D horse. I've asked numerous vets and his chiropractor... they think it just might be some tissue damage from the strained suspensory. My mind keeps jumping to navicular... has anyone had a horse not nerve block for navicular but actually turned up to have it?! Or anyone have ideas?! He wears his PHT wonder wraps, I have Red Light Therapy and he is on his Equivibe everyday.

I would take him to another good lamenss vet and get a second opinion since you are worried about navicular, it may ease your mine a bit.

If he DIDNT block for navicular and DID block higher up then that's the route I would go. South pony is right get a different set of eyes on him and see what they find out. 

Do you think it could be navicular even if the nerve block for it was negative?

This is why you need a second opinion so you wont sit and worry about it

I have one that strained a suspensory, and he's just now sound after just over a year completely off. And I still retired him because he more than likely won't hold up to running again, his was hind though. The general rule for soft tissue, even strains, is 6 months minimum. Usually a good month of stall rest, then hand walking, then turnout in small area. Slowly build up, but generally never back to normal work before 6 full months minimum. It's highly possible its still your issue. I would also hope they ultrasounded it and not just xrays, xrays aren't going to show you soft tissue injuries

Even a strain you are going to get some tears to the fibers.  Suspensories heal slowly and most of the time heal poorly with weak scar tissue in place of the healthy tissue that was damaged. It is common for a horse to appear sound even if he is not healed.

Ultrasounds are the only way to tell what is going on while it is healing.  Was an ultrasound done at any time, to diagnose?  The xrays will rule out bony issues but the ultrasound will give you a definitive on soft tissue.

how did they find a suspensory issue with a Radiograph?