Keratoconjunctivitis Sicca (KCS) is, very simply, dry eye. Here on Doggy Dry Eyes the focus is canine KCS, but you already figured that out. There are plenty of sites describing the condition and what can be done to alleviate the symptoms. Pet Wave is one such site. Web MD is another. I particularly like the information available at Darwin Veterinary Centre. Doggy Dry Eyes focuses on one dog's ocular journey from dry to dewy.
Mary Murphy is a Decker Giant Rat Terrier born in February of 2003. Right from the get-go Mary had health issues. She had a luxating patella which caused her to hitch her little hind leg up and limp like Walter Brennan in The Real McCoys. While she was anesthetized for her spaying, the doctor also cut a small growth off her thigh and pulled a crazy snaggle-tooth. She started having stomach issues around the same time, vomiting bile once or twice (or three or four) times a day when her stomach was empty. If I didn't feed her early enough in the day, she'd puke. If I didn't give her food every 3 or 4 hours, she'd puke. Mary was a mess.
My vet put her on Pepcid and Reglan, and I changed her diet. I'd always been careful about what I tossed into Mary's bowl. I'd been feeding her a Nutro kibble, and since that was about the only thing going into her stomach other than a few Iams puppy biscuits, I thought changing her food might help. After a little research, I switched her to one of the Wellness kibbles and started treating throughout the day with Wellness biscuits. As long as Mary wasn't hungry, the vomiting decreased from twice a day to 2 or 3 times a week. Keeping Mary not hungry increased her weight to 33 pounds, which didn't help her sad little knees.
I know Mary's a Decker Giant, but 33 pounds was too much for her frame. The minute I cut back on her food, however, the vomiting would ratchet back up. So I kept Mary not hungry and reconciled myself to the fact that I simply had a slightly puky, rather portly, lame little pooch.
It soon became apparent that purging and patellas weren't Mary's only problems. Her eyes weren't right. Over the course of the next year, Mary's health issues would turn from a manageable nuisance into a nightmare.