Wolves and Ocelots aren't naturally spawning. The ones I spawn using eggs aren't persistent (not sure if this is default behaviour, though).
I've tested this on both 1.8 and the latest 1.8.3 Spigot builds:
- git-Spigot-550ebac-7019900 (1.8-R0.1-SNAPSHOT)
- git-Spigot-1d14d5f-ba32592 (1.8.3-R0.1-SNAPSHOT)
The former is the one I currently use. The issue is still reproduced using the latter.
No plugins were loaded.