The rib test tells a Mustang's story first
The rib test is the first check on a Mustang suspected of overfeeding, because this breed hides weight under a dense coat and a compact, muscular frame. Stand on a quiet day and run flat hands along the ribcage: on a Mustang at a healthy weight you can feel the ribs with light pressure under a smooth cover. When the ribs need a firm dig to locate, or disappear entirely, the ration has been running ahead of the horse for weeks.
Add the neck to the same weekly check. A soft, thickening crest that wobbles as the horse moves, plus fat filling in behind the shoulders and over the hips, confirms what the ribs suggested before the change is obvious in photographs.
Why Mustangs overfeed faster than domestic breeds
Mustangs overfeed faster because scarcity built their metabolism: a wild diet of coarse grasses and long walking taught the body to store every surplus against a hard season that, in domestic life, never arrives. Rich pasture, sweet feeds, and treat-heavy affection all land on that storage system at once. A Mustang can therefore be overfed on a ration that looks modest beside the buckets given to harder-keeping horses in the same barn.
Appetite is no safeguard here either. A Mustang will meet you at the gate hungry after a full day on good grass, because the drive to eat whenever food appears is the same survival wiring that makes him fat on plenty.
Cutting back without gutting the forage
Cut energy, not fibre, when a Mustang is carrying too much weight. Limit hours on lush pasture or use a grazing muzzle if your veterinarian is comfortable with one for this horse, swap rich hay for a plainer, later-cut batch, and remove concentrate entirely unless a vet has asked for it — most overfed Mustangs are eating grain they never needed. Keep total forage generous so the gut stays busy and the horse stays settled, spreading hay in several piles or a slow feeder to stretch eating time.
Weigh any feed still served, log grazing hours honestly, and re-check ribs weekly while the ration settles. Weight should drift down slowly across weeks; a Mustang crashed onto a starvation paddock is a stressed horse, not a managed one.
When an overfed Mustang needs the veterinarian
Bring a veterinarian in when an overfed Mustang develops a hard, upright crest that does not soften as the ration is trimmed, any soreness on hard ground, a shortened stride, or a habit of shifting weight between front feet. Easy-keeping horses carrying excess fat and showing foot discomfort are exactly the cases where waiting costs ground, and a hands-on examination beats ration experiments. Also call if the horse gains despite a genuinely lean ration, since that mismatch deserves investigation rather than harsher restriction.
Photograph the horse monthly from the side and rear so progress is judged against evidence. A dated sequence of those photographs also settles disagreements between helpers about whether the crest is truly softening or simply being wished smaller. Logging every ration change and rib check in KinsLe through Care Teams keeps the leaner plan consistent across everyone who feeds this Mustang.