stuck on habitat cleanliness is a disease risk

[torvi]

i just started this game and the tutorial i think just ended but im stuck on the ring tailed lemurs. What am I suppose to do to increase cleanliness in the ring tailed lemur exhibit?

[Zero]

I had this same issue with the lemurs in the first tutorial map and also with the macaques in the third tutorial map.

[malcher]

While I can't help with the ring tailed lemur exhibit, I had the same problem as Zero in the 3rd tutorial with macaques. Turns out the keepers couldn't get into the shelter building to clean up poo inside, because it only had a ramp. I demolished a part of the shelter's wall and the message went away. I don't know if it would have worked with a door instead of a hole in the wall, but at least it worked :) Maybe you have a similar situation?
As for lemurs, check if there is poo in the water (I think they have a water area?).

[Seikan]

My zoo flourished for 24 years and then suddenly three of my habitats (which were my first three) were dirty and disease risks.

[Workaholic Zombie]

I found this same issue and it was because the animals would poop on climbing things and the cleaners couldn't reach the poo underneath them. Had to make a few adjustments to supports and the like to solve the problem.

[Seikan]

I completely emptied the habitats and gave them new bedding and shelter (thinking that might have been it at first). Didn't fix it.

[Water_Dragon68]

I had this issue with peafowl in my franchise zoo. I was able to correct it by moving the shelters and bedding to a different part of the exhibit to allow for cleaning underneath, where there was a buildup of poo that the keepers apparently couldn't see/access. I was using the Planet Zoo default shelter you start with, so I don't think the peafowls could climb it (or at least not that I ever saw). I had also lowered the bottom of the shelters to fit closer to the ground so the logs were partly submerged in the ground layer, but still there was poo. It's hard to keep on top of, but I just rotate where the shelters are in the exhibit now when I see the messages popping up. I have more peafowl than I know what to do with anyway, so them getting sick is kinda meh.

[Seikan]

Had a pygmy hippo swim underground and escape... Wondering if my issue is that there is poop underground there.