Join Date: Aug 2009
Location: New South Wales, Australia
All the blankets are too big. While the first two seem too tight on the chest it's because the neck hole is too big and it's sliding back. Too big means too much movement, which means rubbing.
In addition, most of those blankets don't seem to fit well besides the sizing. They don't look like they're made for outdoor use and they don't sit or secure very well. They look like the kind of blankets used for stables, or after riding, when the horse isn't moving around.
I look for a few different things in a rug. If I'm buying a canvas I want a stiff top seam that shapes the rug, and a small neck hole so that the rug sits over and in front of the shoulders. Must have cross over leg straps, many canvas ones just use a single surcingle though.
If I'm buying synthetic I don't care about the top seam, but the neck hole still must be small and cut forward which is where most synthetics fail. Must have cross over surcingles and leg straps, as well as should gussets. If your horse is between two sizes in a synthetic it's often best to go for the smaller size, but it should have shoulder gussets.
Often, if you're buying cheap synthetics, combos fit better because of their different neck line.
I'm of the opinion that usually no rug is better than a poorly fitting one. However, these days rugs are pretty cheap. I'll buy my synthetic rugs off ebay and they fit better, hold up better and just are better than the ones in saddlery 3x their price.
If you're going to continue using those rugs you'll want to tighten the front if possible, and pull the rug more forward.