What Causes Excessive Mucus In Stools?

My dog has excessive mucus in his stools. What could be causing this?

Dogs with colitis will have mucus in their stools. Collitis is irritation of the intestine and can be caused by a range of things from a change in diet or consumption of a large amount of indigestible fibre like grass, to parasites like whipworm or protozoan parasites. There are also some more serious ailments that case this so if it is a permanent rather than intermitant problem then I would recommend a visit to your vet.