Cats die by cactus while in minecart

Cats going around a track by minecart die from being pricked no matter how far away the cactus is.

What I expected to happen was...
Cats to go around scaring creepers

*What actually happened was...:
the cats died when I walked nextto a cactus

Steps to Reproduce:
1. Put cats that have been named in a few minecarts going around a powered or automatic rail
2. Plant cactus on sand 16 blocks (more or less) away
3. Stand next to cactus and listen, cats take damage, you read in your chat menu that the named cats were pricked. Happens to un-named cats