Sticky poop is caused by too rich food, particularly food rich in sugars. Carrots have lots of sugar, and contrary to what people generally believe, carrots are not bunny-appropriate food, they are to be regarded as treats and only fed in small amounts.
Sticky poop needs to be dealt with, because it means the gut microbiota, esp the microbiota in the cecum (big part of rabbit intestines), is out of whack. Sugars make the wrong microbes grow excessively. This makes the cecals sticky and plenty and the bun can’t eat them like he should (there are very important nutrients in cecal poop) and the result is the bunny gets poopy butt.
You treat this by cutting out all sweet treats, cut back on pellets, feed extra hay and choose vegs carefully. Fresh grass is good if he’s used to getting that. Make sure he eats, he mustn’t stop eating or you need to take action. It’s also good if he gets exercise.
It can take a while for this to right itself, the good microbes in the gut need time and fiber to re-establish themselves. So you need some patience and if the poopy butt goes on, you might have to give your bun a butt bath. This is particularly important if he gets outside-time. Flies like poop and can actually and disgustingly enough lay eggs in the poop on the bunny and cause an awful condition known as fly-strike.
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