when players use pet menu i've got this error:
http://pastebin.com/8rrr5WUd
and
http://pastebin.com/fFkPn8gw

if they trie to make baby pets, sometimes it says that they don't have permission but they have it

Echopet version v2.0.5
Spigot #1031

The first issue I have just fixed (thanks to your report 😀) here, the second issue was fixed here, and the permission issue was fixed here.

how do i get these issues fixed in my echopet.jar if i want to implement them right now? Do i have to wait for the next release or can i do it right now in a way?

There are new Dev builds available