Anal glands in dogs are two tiny scent sacs on either side of the anus that store a strong‑smelling, oily fluid used for scent marking and “doggy ID.”

What anal glands actually are

  • Dogs have a pair of small sacs (often described as pea‑sized) just inside the anus at roughly the 4 and 8 o’clock (or 5 and 7 o’clock) positions.
  • The lining of these sacs contains special glands that produce a foul‑smelling, oily secretion, often compared to rotten fish or metallic odor.
  • Each sac connects to the edge of the anus via a tiny duct so the fluid can be released.

Think of them as built‑in “scent bags” dogs carry just under the skin at their rear end.

What they do (and why dogs sniff butts)

  • In the wild, anal gland secretions act like a personal scent signature, used for territory marking and individual identification.
  • The fluid contains pheromones that can tell other animals information like sex, health, and approximate age.
  • This is a big reason dogs obsess over smelling each other’s bottoms and sniffing fresh poop on walks—it’s like checking a social profile.

Normally, when a dog passes a firm stool, the pressure on the sacs helps squeeze a small amount of this fluid out naturally.

When anal glands become a problem

Sometimes the glands don’t empty properly and can become overfull, blocked, or infected.

Common causes include:

  • Soft stools or chronic diarrhoea (not enough pressure to empty them)
  • Obesity
  • Narrow or abnormal gland openings
  • Allergic skin disease or broader gut issues

Typical signs of trouble:

  1. Scooting (dragging the bottom on the floor).
  2. Licking or biting around the anus.
  3. Sudden strong fishy smell.
  4. Discomfort sitting, standing, or defecating.
  5. In worse cases, swelling, pain, or even an abscess and discharge near the anus.

If you see these signs, it’s a vet‑visit situation; they can manually empty the glands and treat infection or inflammation if needed.

Basic care and prevention

While not all dogs have issues, you can support healthy anal glands by focusing on stool quality and general health.

Helpful strategies include:

  • Keeping your dog at a healthy weight.
  • Feeding a balanced diet that produces firm, “pick‑up‑able” poops (not too soft, not rock‑hard).
  • Addressing chronic diarrhoea, constipation, or suspected food sensitivities with your vet.
  • Getting your vet (or a properly trained professional) to check and express the glands if your dog repeatedly has issues—especially before they become infected.

Surgical removal of anal glands is generally reserved for severe, chronic disease (such as cancer or intractable problems) because it can affect the anal sphincter and long‑term bowel control, so vets usually see it as a last resort.

Bottom note: Information gathered from public forums or data available on the internet and portrayed here.