My beautiful, well-mannered cat expresses her anal glands when she is happy, and I thought I was the only one with a cat who did this until last week. Well, that ends today! The anal glands are contained in the anal sacs, and they create a oily, unpleasant-smelling substance that collects within the sacs. The contents of these sacs are then used for marking purposes. When your cat defecates, the anal sacs are squeezed, and their contents are deposited onto the waste. This requires veterinary attention.
anal gland "spraying" while purring. help! | TheCatSite
Anal Gland Secretion in Cats
The anal glands are two small sac-like structures located at 4 and 8 o'clock just inside your dog's and cat's anus. The cells lining the sac wall secrete a stinky, thick, oily fluid. The fluid accumulates in the sac until it's expressed. Dogs and cats have mostly lost the ability to squirt their anal gland fluid at will phew! As the poo goes from the rectum and out the anus, it physically pushes on the anal glands, expressing the fluid.
Overview Anal sac disease is a common and very smelly problem. If you have ever experienced an atrocious odor coming from the backside of your beloved cat, you have probably had the pleasure of smelling anal gland discharge. This fluid, used to mark territory, is normally expelled during defecation.