Oh no! None of your pets are eligible for battle. You might want to make sure that they're well fed and happy!

Echne is

Bloated Very Happy 107/110 HP.

-_-

check to see if the pet isn't in a battle already..I believe going to the statistics page(not sure where), if it's not that I don't know what could be causing it(sorry if this pings you again, edited to add that last bit)

Thanks. I feel foolish now. Apparently I didn't end the battle I lost last night. <3

no worries, I had that happen around the time I first started battling and couldn't for the life of me figure it out.