If you have issues with petfood then look at your spending habits using them, it makes sense that you can't have the storm, golden,fire, coldfire phoenix, brown polar and panda bear 24/7 active.
On average is you see all recipes a week you can aquire about 6-7petfood a week, so your spending habit should be based around this. this is the limit you have to work with and this means making choices where to spend it on and where to save it.
Some people complain pets are unbalanced, and limiting pet food combined with more pets could be in the future a way to balance them.
As you can spend each petfood only once, and therefore have to make choices.
Making choices is what this game is all about, what to build,m where to build, when to use my combat boosters, which units to make, and where to place my magical production spells and when.
There are several strategies to limit pet food consumption, and to maximise its effect.
Also try to build up a decent supply. if you limit your comsumption and have a supply, then in good times this supply will grow a bit and in moments the academy will not give you te recipes you need you can use that reserve to overcome the bad period untill a good one ariives again.