This horse was diagnosed by a veterinary just before I took this video on the left. The vet took X-rays and diagnosed the horse as being foundered without ever using hoof testers. The vet recommended that the horse just needs "a good trimming". The X-ray below does seem to show slight rotation indicating founder, however, a horse that is suffering from founder will never intentionally bare the weight on the toe. And besides that you can clearly see that the heel is not all the way to the ground because the horse could bare no weight on the heel at the time the X-ray was taken. A foundered horse will walk with there feet out in front typically to reduce the pressure on the toe do to inflamation underneath the coffin bone. This was a red flag to me because the horse is tip toeing indicating the horse is trying to get the weight off the heel or back of the hoof (the horse is showing us where the problem is in this case). I tested the hoof and not to my suprise there was no reaction in the hoof using the hoof testers. The only place the horse was sore was in the bulbs of the heel (not a typical place to be sore with a horse that is foundering). As I squeezed the bulbs and put pressure on the back of the foot above the hair line, I noticed how hot the foot and leg where and how censitive the horse was to just my hands touching her. I realized this must be an abscess, and the abscess had caused swelling up the leg to the ankle. The owner started soaking the horse in epsom salt and I put a ichthammol poultice on covering the back of the foot. 8 weeks after soaking and changing the poultice out once a week the abscess finally busted out right above the hair line on the outside bulb. The hole in the back of her foot drained pus for days but gave the horse immediate relief. The horse is walking and feeling great now thanks to proper diagnosis and proper treatment. 
Abscesses can be tough to find and can be long lasting
more coming soon!