Originally Posted by gothicangel69
environment, feed, and trim schedule. His feet are always done every 4 weeks- and never more than 5. He does have slightly underslug heels, ....He only has one small crack in the back which happened a few months ago and almost grown out- before this started. It was from a trail ride on pavement though,
Sounds OK. If he has underslung heels, very likely got 'run out' toes too, which has put more stress on the laminae around the toe region & allowed the infection into the stretched white line. While cracks are frequently due to insufficient or imbalanced trimming or such, your trimmer may have trimmed his walls appropriately for his normal environment, which was just too long or such for riding on pavement.
Apparently a ton of people in the area have it, and I'm thinking its from the poor hay this year. We usually never see white line disease around here unless the horses are kept in unacceptable conditions.
Yeah, nutrition could be a factor & horses with well balanced nutrition are said to be *less susceptible* to infections, but the cause is bacterial/fungal and it's an 'opportunistic' infection, meaning it only invades unhealthy/compromised feet.
DimSum, looked at your link & I used to think of it as 'common knowledge' that horse's hoof growth slows down as they age. Now I'm not so sure. Healthy, well functioning hooves grow much quicker than compromised feet and well used - lots of exercise - grow much faster than 'paddock puffs'. I've also had some experience rehabbing 'slow growing' feet, who's owners report faster growth than they've seen prior to getting me(not apparently related to season, diet, etc). I think good circulation is a huge factor, & re what they said about heart rate, I think it's probably more about aerobic exercise/circulation.
Oh & hoof horn - wall, bars, sole - grows out from the laminae as well as the outer wall growing down from the coronary.