Dogs can have allergies to a lot of things...food, airborn, things, etc. Some goop in the eyes is natural. The goop, esp. if it is greenish or mucus-y though, can be an indication of an allergy. The vet can do testing to determine exactly what specific allergies by be there, but it can be expensive.
Sadie has an allergy that we are pretty sure is not food related. She gets goop in her eyes and licks her paws A LOT!!! We have treated this in two ways. First we give her a vitamin supplement to mositure her coat and pads. Second, we give her Benedryl twice a day. It has really helped her a lot. (if you want to try these, please, check with your vet first!)


The other reason for excess gunl couldbe an infection. Check the whites of Presley's eye to make sure they are not red. Hold her head and gently pull her skin back to see the upper part of her whites (the bottom area is redish pink because of the 3rd eyelid) If this appears discolored, she may have an infection and it can easily be treated with antibiotic

Can you tell we have had some eye issues with our dogs?!?