What’s his diet like?

If it is incontinence, this could be caused by a number of things (e.g. E. Culi, a URI etc) and the only way to find out is bringing him to a rabbit savvy vet.

I agree with Kurotta. Sudden incontinence is an issue for the vet, unfortunately.

Do you mind sharing which brand of pellets is that? Pellets that are too rich or have a bunch of other unnecessary ingredients sometimes cause sticky poop.

That said, he should still go to a vet for the incontinence issue especially since he’s already 8 years old.

Hmm is there any particular reason why he is getting this specific kind of pellets? it seems like the pellets contain a lot of unnecessary ingredients – perhaps that’s what’s causing the sticky dark poops since he’s getting older and may not be able to digest it properly. Has there been any other diet changes recently as well? E.g. introduction of a new vegetable etc.

Do update us once you’ve gotten him to the vet!

Grocery shop pellets usually aren’t the best nutrition wise I recommend you do some research and find out if there’s any appropriate pellets in your area. There are certain requirements when it comes to pellets, concerning fibre and protein. Here’s a link you might find useful http://www.therabbithouse.com/diet/rabbit-food-comparison.asp

Switch him to a healthier pellet gradually to avoid upsetting his sensitive tummy. Since he’s used to getting all the unnecessary stuff, he may be reluctant to eat the new pellets at first, but keep on trying. Oxbow pellets for adult rabbits is a good recommended brand by most people.

Do still take him to a rabbit savvy vet though – older buns are more susceptible to illnesses and you’d want to rule out any other possibility.