Subclinical Acidosis

Subclinical acidosis is thought to result from overconsumption of either high-starch concentrates (not applicable to Anky) or an intolerance to pasture grasses rich in fructans (highly likely applicable to Anky). All the info's in the link, but basically it boils down to a lowering of  ph in the hindgut which then becomes overwhelmed with acid and causes serious damage to the intestinal mucosa.
The intestinal lining becomes inflamed and irritated, causing the horse discomfort. The irritation may be severe enough to induce behavior characteristic of colic. Long-term exposure of the intestinal lining to a low-pH environment may negatively affect the absorptive capacities of these structures affecting the ability to absorb nutrients.
Because of the precarious nature of the hindgut of a horse afflicted with subclinical acidosis, it is less able to handle metabolic crises that healthy horses may be able to fend off. Hence, horses with subclinical acidosis are more susceptible to colic and laminitis.
Symptoms include;

• Decreased feed intake or complete inappetence in severe cases
• Mild to moderate colic signs of unexplained origin
• Poor feed conversion efficiency and subsequent weight loss
• Bloating
• Loose droppings and behavioural issues

 All these things apply to Anky, but no vet has ever mentioned this to me. Why?
I don't know why, but when I found the article it immediately seemed to me that this might be the missing piece in the jigsaw.  If this is Anky's problem then we can treat it. On verra -we'll see.