It’s most likely to be related to the overall diet being too high in NSC, whether it’s due to the sugar, or the starch, or the combination
[My understanding is that the founder risk is NOT related to sugar levels, but to something else in the alfalfa. Sugar levels are culprits in Cushings, and other metabolic diseases (which may, in turn lead to founder), but not a direct cause of founder.
Of course sugar and starch are directly related to laminitis. That doesn’t mean all high NSC diets result in laminitis, and it doesn’t mean all laminitis is directly (or indirectly) related to a high NSC diet (think mechanical laminitis). But the whole issue with IR horses is their total NSC needs to be low (and sometimes lowwwwww), and that’s a function of sugar and starch.
That doesn’t mean that some IR horses don’t have a problem with alfalfa despite it’s generally low NSC
Sure they can. Horses born and raised in the SW do it all the time.
yes, they can - see above. There are areas of the country - the SW mostly - where it’s alfalfa, or nothing. Many, many horses are raised on and die on (old age) straight alfalfa diets.
Is that ideal? No. Is the alfalfa of the SW different from that on the East coast? Absolutely.