Cats have muscle glands on either side of their rectum. These glands give each cat’s bowel movement a unique odor which enables cats to identify interlopers in their territory. These same glands have developed in skunks to offensive potential. Normally, these glands secrete a small amount of oily, extremely pungent musk when the cat defecates or gets very excited.
For reasons we don’t understand, sometimes these glands become blocked and secondarily swollen and infected. When this occurs, your cat may attempt to empty their glands by dragging his or her butt along the floor (called scooting). Other signs might be the inability to terminate a bowel movement correctly, resulting in feces stuck to the rectum, feces dropped outside the litter box, or urination or defecation in an area other than the box. Sometimes, the cat will be grouchy, sensitive in the rear end, or licking his butt frequently.
The swelling in the glands causes pain upon defecation, which may drive the cat from the box. This may also result in constipation and/or straining to defecate. Not infrequently, urinary problems may develop because of the relationship of anal gland area nerves to the enervation of the urethra. If the glands outflow duct is fully blocked, eventually the pressure builds and the glands may rupture through the skin near the anus. This is called an anal gland abscess, which will require surgery and antibiotics. If you observe any of the aforementioned symptoms, we should see your cat.