My Dog Is A Mix Of Collie, Rottweiler, And Doberman.

My dog is a mix of Collie, Rottweiler, and Doberman. He is about 2 years old and has excessive eye drainage. I believe it is a yellowish color, and we have to clean his eye about once a day. He is also not eating, it may be due to the fact that he was recently at a kennel and was refusing to eat until they mixed in food samples. Do you think he has anything and needs to go to the vet, or should I just keep an eye on him?