Horses and laminitus?

Question

why is it horses living in the welsh mountains dont get laminitus.

Answer 1

OK, Welsh Mountain ponies do get laminitis, but your question is why is it when they live in the Welsh Mountains, don't they get laminitis.

http://www.heavenlypony.com/laminitis.ht...

The centuries of harsh conditions the Welsh Mountain Pony has endured has ensured the sound constitution, iron hard limbs and great intelligence which, combined with the legendary Welsh temperament, makes the ideal child’s pony of today. They can be seen ridden and driven all over the World – equally at home in the cold of Canada and Sweden or the heat of Africa and Australia.

On the upland farms of Wales, Welsh ponies and cobs would often have to do everything from ploughing a field to carrying a farmer to market or driving a family to services on Sunday. When coal mining became important to the economy of England, many Welsh ponies were harnessed for use in mines, above and below ground. In the 18th century and 19th century, more Arabian blood was added by stallions who were turned out in the Welsh hills. Other breeds have also been added, including the Hackney, Thoroughbred, Norfolk Roadster, and the Yorkshire Coach Horse.

One of the more common causes of laminitis. Current theory states that if a horse is given grain in excess or eats grass that is under stress and has accumulated excess non-structural carbohydrates (NSC, i.e. sugars, starch or fructan), it may be unable to digest all of the carbohydrate in the foregut. The excess then moves on to the hindgut and ferments in the cecum. The presence of this fermenting carbohydrate in the cecum causes proliferation of lactic acid bacteria and an increase in acidity. This process kills beneficial bacteria, which ferment fiber. The endotoxins and exotoxins may then be absorbed into the bloodstream, due to increased gut permeability, caused by irritation of the gut lining by increased acidity. The endotoxaemia results in impaired circulation, particularly in the feet. This results in laminitis.

Nitrogen compound overload

Herbivores are equipped to deal with a normal level of potentially-toxic non-protein nitrogen (NPN) compounds in their forage. If, for any reason, there is rapid upward fluctuation in levels of these compounds, for instance in lush spring growth on artificially fertilized lowland pasture, the natural metabolic processes can become overloaded, resulting in liver disturbance and toxic imbalance. For this reason, many avoid using artificial nitrogen fertilizer on horse pasture. If clover is allowed to dominate the pasture, this may also allow excess nitrogen to accumulate in forage, under stressful conditions such as frost or drought. Many weeds eaten by horses are nitrate accumulators. Direct ingestion of nitrate fertilizer material can also trigger laminitis, via a similar mechanism.

Assuming the ponies living in the wild did not have the problems associated with the carbohyudrates in their guts because they did not eat grain. They could still get nitrogen buildup from rich grass in the spring.  I suspect they did get laminitis especially if the hills were clover based.  Ponies living in the wild do not get treated for illness and just get weak and die.  I have not found any articles or documents that state these ponies do not get laminitis in the wild.  They certainly are prone to both forms of laminitis as all short heavy body ponies seem to be.