My small 16 1/2 yr old chihuahua mix who recently passed from cancer and also had chronic pancreatitis and gallbladder disease had to eat a prescription kibble this past year and would swallow the regular size kibbles without chewing. He wouldn’t eat it moistened and since he had cancer and was losing weight, I was afraid he’d stop eating, I let him do this. In retrospect, I should have tried breaking it into smaller pieces but I was afraid of changing anything because he was eating without choking, not vomiting, and did not have diarrhea. I was wondering if I had hurt him in anyway by doing this (maybe he would have eaten more if I had). He had teeth but I don’t know if he had any problems as he was too sick for another teeth cleaning. I am still grieving his loss. He did live a year with untreatable cancer.
Cancer is a common condition in older dogs and I don’t think you made things worse by feeding him the kibble. I know from experience that at times like this, you do what you can to make their life as comfortable as possible, particularly if the dog has an untreatable problem. We look back and wonder if we could have done things better but it doesn’t do to dwell on things that cannot be changed. Your little dog lived to a good age so you must have done something right.