Hello! I'm rehabilitating 4 lovely southern flying squirrel babies and they are around 7-8 weeks old. I switched them over to Fox Valley 20/50 around 5 weeks, and started supplementing Henry's Healthy Blocks at 6. They're about halfway through their current bag of 20/50 and I went to order more today but Henry's Healthy Pets is out of it in all sizes, all departments, and all other sellers! What other formula/brand is the next best? Thank you! :)