Is it better for a horse blanket to be too big or too small?

I've never sat on a horse, but "is it better for a horse blanket to be too big or too small?" is a question riders really do ask, so here it is. The sources we read don't crown a winner: they describe a different problem for each, and several say neither is the safe choice.

Our horse blanket guide puts the two failure modes this way: a blanket that's too big slips and rubs, and one that's too small restricts movement and causes pressure points. Rutgers' Equine Science Center says blankets that are too big or too small can cause sores on the withers, rubs on the shoulders and general irritation. The sources differ on emphasis, which the next sections lay out. For a horse's health questions, such as sores or hair loss, your vet is the one to ask.

In Equus, show-barn manager Bates is quoted saying people tend to buy too large a blanket, and it slips back, putting more pressure on points of the shoulder. The article, which first ran in 2001, also says loose blankets shift, rub and can entangle the legs.

In Horse Illustrated, Liz Wilkinson of WeatherBeeta says that a blanket too big is actually more likely to cause rubs than one that is too small, and can be dangerous, citing the horse getting tangled in the surcingles or stepping on the back of the blanket when he gets up after lying down or rolling. Veterinarian Peters, quoted in Equus, says that if the surcingle hangs four to six inches down, a horse can easily stick a foot in there when he lies down, and that the front opening shouldn't lie in the slope of the withers.

University of Maine Cooperative Extension makes the same point from the strap side: leave about three fingers of room between the belly and the belly strap, let rear leg straps droop a little without hanging low enough to catch a hoof, and face clip openings toward the horse so they don't catch on hay bags or other hazards.

Rutgers lists sores on the withers and rubs on the shoulders for a blanket that doesn't fit. Our horse blanket guide says a too-small blanket restricts movement and causes pressure points, and that once the blanket is on you should be able to slide your hand flat between the front of the blanket and the withers, because pressure there causes rubbing quickly.

University of Maine says the same check from the shoulder: slide a hand under the blanket against the point of the shoulder and the withers to look for rub spots; if your hand barely fits, loosen the chest straps or try a larger size.

Length counts too. Our horse blanket guide says the blanket should reach the top of the tail, covering the hindquarters without going past the point of the buttock; too short leaves the hindquarters exposed, and too long shifts the whole blanket back as the horse moves. If you're seeing rubs on a blanket that otherwise seems the right size, our blanket rubs page covers cut, gussets and guards.

Our horse blanket guide says that between two sizes you should go up, because a blanket an inch too large is more comfortable than one an inch too small. Our horse blanket sizing page says WeatherBeeta's own advice is to choose the bigger size, and that riders sizing Shires go up for a broad chest, though a smaller, trim horse can swim in the larger size.

Other sources push the opposite way. The Equus fitter above says people tend to buy too large. Our Horseware guide notes that several of our customers size down when between sizes in Horseware blankets, and that fit still varies by model, so check the size chart on each product page. University of Maine says each blanket brand may have a different way of fitting, so measurements alone won't guarantee a match.

That's University of Maine's wording, and our horse blanket sizing page describes the same route; Rutgers ends at the center of the thigh next to the tail. Stand the horse square on level ground, with a handler at his head, and read the number against the chart for the maker you're buying.

Makers differ. Our horse blanket sizing page notes that Horseware asks you to take 4 inches off your tape reading before using its chart; our Horseware blanket sizing page has the details. Horse Illustrated says the sizing varies by brand and style and tells riders to follow the manufacturer's measuring instructions, and that length should be checked first, since the other features won't fit properly if the length is wrong. We don't print size numbers here: each maker's chart is the one to use.

Rutgers says to round to the nearest even number if needed, since some companies only sell even sizes. And remeasure: our horse blanket guide says a blanket that fit two years ago may not fit the same horse today.

Horse Illustrated gives a checklist in the words of the makers it quotes:

• Front: after fastening, the blanket should sit in front of the withers, not behind them or directly on top of them.
• Neck: big enough for the horse to lower his head to graze, but not so big that the shoulders can pop out.
• Drop: long enough to wrap under the belly for extra coverage.
• Bottom edge: the same distance from the ground at the withers and the rump.
• Movement: walk the horse around to check for pressure points or tight spots.
• Hand test: University of Maine says to slide a hand under the blanket at the point of the shoulder and the withers to look for rub spots.
• Strap check: about three fingers between belly and belly strap; leg straps that droop a little without hanging low (University of Maine).

It says blankets can hide changes such as weight loss or gain, skin fungus or bacterial infections, and blanket rubs. University of Maine similarly says to remove a long-term blanket occasionally to check for rubs and body condition. A weight change in either direction can change fit. If you see hair loss, sores or skin problems, that's a call for your vet.

If the fit seems fine but he's too warm or too cold under it, that's a weight question; see our blanket weight page. If you're unsure which cut suits his shoulders and withers, our blanket cut page and our sizing page can help.