I just went through this with Bobber. Yes, they may already be full again and if they are not expresed they can be impacted or abscess- in which a new hole will appear near the anus and drain and I don't have to tell you what that can lead to. Out of the blue Bobber needed her's expressed and the conventional vet did. Less than 2 weeks later I was stunned to see one had abscessed! Conventional vet cleared with antibiotics etc. and 2 or 3 weeks later they need expressed again!!! and one had scar tissue on it also. So at this point I think its out of control-needing expressed so frequently/abscessing etc.- and no advice or hope offered from conventional vets. My holistic vet-Dr. Boswell- who is a special true healer like Dr. Cuoto- told me that it was believed that The Missing Link often helped. I also contacted my kibble manufacturer-Solid Gold- for feeding recommendations if any as they really have helped me in the past. Solid Gold said they would put her on their new food Barking at the Moon and told me why. So I started feeding her 90-95% Barking at the Moon with the Missing Link added as an additive and its been almost a year now and there have been no anal gland eruptions and they have been expressed only once in all that time!! I think if it works don't fix it so I'm leaving her alone now-no regularly scheduled expressions. I don't know if either product alone is responsible or maybe neither but Im not changing a thing. She's healthy, no anal gland problems anymore, and she'll be eating Barking at the Moon with the Missing Link forever. I'm not about to change. She does get treats and a fair amount of "human" food and some raw meat too so its not so bad- as she does get enough variety to enjoy her meals. Good luck. Hope this helps.