The best replacement for cages is stakes.

The best alternatives to cages are rated as following:
★★★★★  stakes
★★★★  straps
★★★  hutches
★★★  crates
★★  clipless
★★  trellis
★  hq
★  kennels
★  steel dog cages
★  boaphile
★  dome bird cages
  pens
  dome top cages
  peek
  tanks

Your alternative for cages is not listed? Suggest!
Speaking about cages, one probably shouldn't forget about pitching machines.

Other search terms related to cages and their ratings are:
★★★★★ pitching machines
You have in mind a companion for cages and it is not yet here? Propose!



Google Trends

Scale is based on the average worldwide traffic of cages in all years. Click on graph for more.
cages
stakes
straps