It was the T-4's that he wasn't producing that caused the problem. It usually can be fixed with surgery. If it isn't fixed, it can cause the dog a lot of discomfort, and eventually will bring on blindness. Sometimes the first surgery doesn't take. Weepy, running eyes are a major indication of entropion.
Allergies can cause weepy, runny eyes.
If you can't tell entropion from an allergic reaction, don't buy the dog. Even if the chow has allergies, I wouldn't buy it. You are just taking home a lot of future vet bills. Hip Dsyplasia a deterioration of the hip socket that can eventually crippled the dog. A faint clicking sound from the rear of the dog when it is walking.