Too much luck. Working on upgrading all my commons to 9. Then will work on pushing everything to 15. Just upgrade what you can. It shouldn't be possible to hit a roadblock once you've opened all the pet food crates. But if the drop tables are TOO random. That might be possible.
To get items for the super rare pets you need to upgrade your common pets to at least level 20 or your rare pets to level 15, to upgrade rare pets to level 10 you need to upgrade your super rare pets to level 5 and your common pets to level 15
I have enough items to get my SR Dog past level 9 but I've already got my Rare Cat past level 14 and the stats are greater. I'm aware lv 14 SR is better than R, But the wait times is like 6~8 days