A mare with one of the AIS syndromes would likely be taller than other mares and while would likely show increased testosterone over other mares, would actually be getting less muscle building steroid activity than XX mares get from their lower testosterone. But there are other conditions that could have other outcomes.

AIS is a biochemical thing and is probably the same for most mammals, except maybe the protheria (egg-layers), mesotheria (marsupials) and odd groups like the mole-rats. Cervine animals (deer and their ilk :)) have some hormonal oddities, too. Bovines (cattle, buffalo, antelope) are only a bit odd and are known to have AIS individuals with similar symptoms to humans.

A different chromosomal oddity accounts for fertile calico males in cats: mosaicism/chimerism. M/C, by the way, turns out to be improbably common in primates. We're primates.

I've been reading on this lately. :)

Hugs,
Erin

= Give everyone the benefit of the doubt because certainty is a fragile thing that can be shattered by one overlooked fact.