Expert: Jessica - 1/26/2010

Question
Hello,

My cat's butt is not a very dirty one but sometimes there are stains or residual poop hanging around. Today I could not resist the urge to wipe his butt and when I did, it squirted out a brown, smelly stain. What is that stain and should I be worried?

Thanks,
Allie

Answer
Hi Allie.  What you're seeing is anal fluid.  Cat have glands that manufacture this pungent fluid, which is stored in two anal sacs just inside either side of the cat's anus.  It's thought that cats were once able to spray this fluid voluntarily as a means of defense, much like a skunk, but this ability has faded over time.

In most cases, the anal sacs are emptied when the cats has a bowel movement.  However, some cats produce too much of the fluid, or the stools are too soft to express the fluid.  These cats may release the fluid when startled, or they may scoot their bottoms along the floor to express the fluid themselves, leaving stains around the house.  

The fact that you're seeing the fluid and a dirty bottom might indicate that he's experiencing some soft stools.  Keep an eye on his bowel movements.  If they're soft, he should see a vet in case he has parasites, a bacterial infection or food intolerances that are causing this.  Remember that litter may dehydrate his stool and cause it to appear firmer than it was when it was fresh, so if you can catch him in the act, this will be the most accurate time to evaluate his stool.  I know it's gross, but it's a good way to judge his health!

If he doesn't have soft stool, it's possible he's overproducing the fluid, which is not in itself a health problem.  However, these cats are more likely to experience engorged or impacted anal sacs which the fluid either overflows from constantly or cannot escape from at all.  This condition can be quite uncomfortable, and at times, the anal sacs can become infected.  It's best to have the vet take a look at him if you notice he is rubbing his bottom on objects, if he's licking his rear end a lot, or if there is fluid regularly leaking for his behind.  The vet may need to express the anal sacs manually.  This is done by placing a finger into the rectum.  If the problem persists, surgical removal of the anal glands may be recommended.

Hope that helps!

Jessica