What I did when I tried getting my leopard to eat it was to cut off the sharper edges and that was it. You can give them a bigger chunk of chop it up in tiny pieces.
We purchase 1 -1.5 foot long aloe leaves at our Asian market. I usually start from the sharp pointy end and cut a piece about 4 inches or so. Then I slice the very pointy ridges off from each side in one slice and cut the remainder into chunks. Our Sully loves his aloe, will seek this out before dandelion, pumpkin or mazuri. The nice thing with the aloe is the “wound” on the remaining piece will dry over and heal until we cut again. This one big aloe stem will last a few weeks like this. Bonus! No spines like cactus pads.