I had the vet out 6 weeks ago and the only thing we could find was an extremely sore back. My mare passed a lameness exam with flying colors. Which is what I suspected. I trail rode her and light work for many many months, put her on ulcer meds but found out her hind gut still had ulcers. In the meantime we started working towards jumping. All of this came to a grinding halt with the sore back. Ulcers are now treated and vet injected the sore muscles. For the last 6 weeks we slowly have been working to increase strength. Hills, poles, long and low with short trot canter sessions and transitions. She still has some evidence of toe dragging on on foot, and will still struggle some days. The days she's good, she looks amazing and feels amazing. How long do I wait before having the vet out again to make sure there is nothing else wrong? Is 6 weeks still too short of a time to really see a huge improvement on the back muscle strength? The vet warned having the back feel better could show something else, I still don't see anything else at all.
A sore back is always caused by feet until proven otherwise.
I changed farriers about 6 months ago. They went from low heel and long toe to short toe and higher heel. Which is what her angles should be. According to xray. But maybe the change caused some stress to her back muscles and way of going.
Not sure of your location, but do you have low or no Selenium in the local soil? We had back issues on a mare, who was just "off" for no discernible reason. She also was in heavy conditioning work. After lots of other things, we did a Selenium test and found she was at an extremely low level. She got the Selenium shots, she was so bad, then oral Selenium and Vit E, to get her back up to normal. The back issue was her abnormal cycling, she had huge egg clusters on her ovaries, which had to be flushed off.
With Selenium and Vit E addition to her body, things got straightened out pretty quick, so she was again performing well, no sore back, not off with tired muscles. Horse was not being ridden at all, only driven, so sore back was a mystery in the general problem. No saddle issues to cause the problem which confused us, since any LIGHT spinal pressure in the loin area could put her on her knees. So a sore back is NOT always a hoof or saddle issue.
As we "studied up" on Selenium, it was rather amazing how many things it affects in the body, muscles, reproductive tract, recovery rates, especially if horse is being worked regular and sweating often. They sweat off Selenium, and if the local dirt is Selenium poor, then they don't replace it. We now top dress the Selenium and Vit E on EACH horse's grain, to KNOW they are getting enough daily. We WERE feeding that mare grain with Selenium added, but no Vit E and not in enough quantity to provide what she needed in work.
Selenium tests are not too expensive, and if you have good numbers, you can rule it out as the problem. We get new horses Selenium tested, because you can't tell by looking, if they have enough to be worked hard. A Virginia horse came to us, supposed to have been in hard work, but sure tired quick for us. Selenium test showed his levels to be extremely low, so Vet stopped by THAT DAY to give him the shots. Afraid he would keel over if not treated immediately!! He was bright eyed, shiny enough to blind you, active, but still super low in his Selenium levels.
I don't think Laurierace is too far off, but my personal theory is that it's hocks first, then feet (front specifically) more often than not. HOWEVER, when it's not, I like the selenium suggestion and then I would also recommended checking to see if this horse is a PSSM candidate and perhaps needs more fat in her diet. And to directly answer the OP's question, six weeks should yield you some answers but not if you're still riding her.....have you been off her back all this time doing ground work that would strengthen/relax her back and give it a break??