Reasons why your pet may not be able to Battle: It may have 0 health It may be Hungry It may Already be in a battle.

Check your pet out, And make sure it Isnt any of the above

Just So You Know, I Imagine It Is Very Painful For You To Type Like This. It Is Actually Making My Fingers Hurt. So, I'll Let You In On A Secret. You Are Not Supposed To Make Every Word Capitalized. I Just Noticed You Missed 'Never' In Your Post Above, Actually. Was That A Mistake?

Anyway -- Your pets have to be fed/played with to battle, and have more than 0HP.