Skin lesions are one of the most common reasons for cats to visit the veterinarian. It’s no wonder because a cat’s skin and fur are right there on the surface, easy to see. 

A conscientious cat lover will regularly look their cat over and make note of irregularities. I’ve had questions about black spots on a cat’s anus more than once over the years. People want to know if they’re normal or something to worry about. 

Let’s talk about a few possible causes of this physical change…

KEY POINTS

  • Some black spots on a cat’s skin can be normal variations in skin pigmentation.
  • Skin cysts and tumors can appears as black spots around a cat’s rear end.
  • Your veterinarian can examine your cat and make a recommendation for diagnostic testing of unusual skin lesions if necessary.

Are Black Spots on Cat’s Anus Normal? 

There are a few things that cause black spots on a cat’s rear end that are absolutely normal and should not cause alarm. 

First, certain cats can develop a hyperpigmented spot(s) called lentigo anywhere on their skin due to a normal genetic variation. 

Similar to freckles in humans, orange, cream and silver-colored cats often develop flat, irregular black spots on their skin as young adults. (2) You might notice them on the kitty’s lips, nose, eyes and ears where there isn’t much hair. These dark spots can show up anywhere, though, including the hairless area of their bottom end. 

I’ve occasionally seen cats that have dark spots that look more like “beads” or slightly raised areas around 4:00 and 8:00 of the sphincter. These are the normal openings of the anal sacs and the dark spots are normal anal gland secretion. Sometimes excess secretion can indicate anal sac disease.

lentigo on a cat's nose (black spots on cat's anus)
Spots like this are normal and can show up on a cat’s rear end, too.

Finally, it is very common for cats to have a little bit of dried feces on their bums. It’s not too surprising considering they aren’t able to wipe and some may not be able to clean the area well during self-grooming. You’ll have to look closely while the cat is in a brightly lit area, but you can usually tell when black spots are actually flecks of stool.

Causes of Abnormal Black Spots on a Cat’s Rear End

There are several diseases that come to mind when considering dark lesions on a cat’s hiney. Some are more dangerous than others but your vet may want to do a biopsy before they can give you a prognosis. 

Some causes of abnormal dark spots on a cat’s skin…

  • Comedones are also known as “blackheads.” They are made up of normal skin secretions trapped in a hair follicle. Strange as it seems, you can occasionally find these on a cat butt. 
  • Cystadenoma is a little cyst filled with secretions from epithelial glands. They’re usually raised and nodular and bluish-gray in color. They are non-cancerous tumors. (1)
  • Dermal melanocytoma is another non-cancerous tumor made up of darkly pigmented melanin-producing cells. A biopsy is required to distinguish a melanocytoma from the next type of tumor…
  • Malignant melanoma is a rare but aggressive form of skin cancer. These also look like dark nodules in the skin. 

If you see any of these on your cat’s rear end, please don’t try to squeeze it! Trauma can cause inflammation and may even contribute to the spread of abnormal cells to other areas of the body. 

silver tabby cat's butt
It’s hard NOT to notice abnormalities on a cat’s butt!

4 Steps to Take If Your Cat Has Black Spots on Their Bum

Don’t panic and investigate the situation a little more. Here are some things you can do at home to understand what’s going on even before you take your cat to the vet…

  1. Make note of any other symptoms. Think about general cat health issues like appetite, drinking, litter box habits, weight loss and energy level. Also, look and feel the cat’s entire body for other skin abnormalities.
  2. Examine the affected area closely with strong light and magnifying lens. You can try gently wiping the dark spots with a soft, wet washcloth. You may need a little mild soap and or water-based lubricant like KY Jelly to loosen up dried stool. 
  3. You can also have your cat soak in a shallow basin of warm, soapy water. Sponge the water over the rear end if your cat won’t sit in the basin. Don’t rub the delicate tissue on your cat’s rear end. That can cause irritation and may make things worse.
  4. Schedule a visit to the veterinary clinic right away. Your vet will do a thorough exam and recommend the best next step. Your cat may simply need some expert grooming or could require anesthesia for a surgical biopsy. 

Summary

Normal causes of black spots on a cat’s anus include benign lentigo spots, comedones and anal sac openings. Abnormal causes of lesions in this area include benign and cancerous tumors and clogged skin follicles.

Your veterinarian is a great resource and should be consulted when you find any new spots, lumps or bumps anywhere on your cat. Don’t hesitate in seeking help as quick action can lead to a better outcome for your furry friend!

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Related Posts

  1. Loft, K. E., Soohoo, J., Simon, B., & Lange, C. E. (2022). Feline cystadenomatosis affecting the ears and skin of 57 cats (2011–2019). Journal of Feline Medicine and Surgery, 24(4), 351-358.
  2. Stokking, L. B., & Campbell, K. L. (2004). 48. DISORDERS OF PIGMENTATION. Small Animal Dermatology Secrets E-Book, 352.