Most folks who buy soft packs opt for one of the many options made for dogs. They're not great, but they get the job done for small goats carrying light loads. The reason most goat equipment makers don't sell soft packs is that they tend to not work well. Without a rigid tree, a pack likes to slide side-to-side and needs constant readjustment, particularly since a goat is not a symmetrical creature. Their rumens bulge out on the left side and change size over the course of the hike. Perfect balancing of the panniers (with maybe a few ounces more weight on the left side) helps, but it never completely eliminates sliding.
One thing to look for in a soft pack is a design that allows room over the spine. Some soft packs are made with a foam pad on either side in the same place as a rigid tree would sit on a sawbuck. This places the load on the ribcage where it should be, and it allows air to circulate over the spine. Packs that are designed with a strap or piece of cloth that rests directly on the spine (like horse saddlebags) should be avoided unless you can modify it with your own pad. Packs that rest directly on the spine can be used for the occasional outing, but they should never be cinched down tightly or loaded heavily.
Good luck!
One thing to look for in a soft pack is a design that allows room over the spine. Some soft packs are made with a foam pad on either side in the same place as a rigid tree would sit on a sawbuck. This places the load on the ribcage where it should be, and it allows air to circulate over the spine. Packs that are designed with a strap or piece of cloth that rests directly on the spine (like horse saddlebags) should be avoided unless you can modify it with your own pad. Packs that rest directly on the spine can be used for the occasional outing, but they should never be cinched down tightly or loaded heavily.
Good luck!
