Suggestion:
Either increase fodder amount for pets dropped from eggs, or alternatively buy fodder with amber from the shop.
At this moment in time, its understandable that leveling pets star level should be hard. The only way to get high star, is to be lucky and pull one from eggs with a low chance. It becomes hard when you need 19k for a level 10 pet and you constantly getting 6 fodder from 10 eggs that you bought for 800 Amber.