Saturday, October 18, 2008

Calling for Frost

Grass photosynthesizes during the day while the sun is out and the nutrients it produces are used to drive nighttime growth. It's generally safest to graze founder-prone horses in the morning because the plants have depleted their sugars through the night. One exception to this rule is frosty mornings -- cold nighttime temperatures can slow or halt the use of sugars such that the grass is dangerously sweet by the time morning rolls around. It is cold and clear in Deroche this evening, so Raven and Tonka will be confined to the paddock tomorrow. Maybe they will help David and I finish their shelter.


Black Jack's Carol said...

Interesting about sugar. I had no idea it could change day-to-day in plants (science brain non-existent). It makes so much sense to me that it would be a trigger for founder flare-up (can one describe it that way?), as I figured out about two years ago that it causes arthritis flare-ups in my bad knee (too much jogging years ago). I seem to be fine with fruit and vegetable sugars, so the parallel is not perfect, but avoid most other sweeteners.

dp said...

BJC: There a lots of things that can cause a horse to founder, but too much sugar is the most common culprit. Some horses cannot produce enough insulin to cope with large influxes, and the sugar gets digested by gut bacteria instead. These bacteria can then wildly reproduce, and they produce an endotoxin that indirectly attacks the laminar tissue holding the hoof capsule to the coffin bone. Swelling of this laminar tissue is called "laminitis" and failure of this tissue (allowing separation between hoof and bone) is called "founder". In the most extreme cases the coffin bone will rotate right through the sole hoof (sinker) of the hoof will slough off entirely. The process is more complicated of course, but that's the gist.

Tonka foundered some time before I got him. His front coffin bones were both rotated with some remodeling of the bone to accommodate for its new position. In January I will have him x-rayed again to see how successful we have been in returning his coffin bones to their natural position. See here.

In my care he has had one moderate laminitic attack due to some kind neighbors feeding him too many carrots (carrots are very sweet, as it turns out). Now we have the tub of alfalfa cubes hanging from the fence.

allhorsestuff said...

Oh MY!
I guess..too much of anything= is not a good thing!
I just found my Oct. Horse Journal
It has the whole investigeting research spotlight= upon "Treats"
this time.