Why does my dog do that?
Why do dogs sniff each other's bottoms when they meet?
Last updated 23 September 2026 · How we write and check this
Short answer
Rear sniffing during a greeting lets dogs access scent from the anal glands, which carries detailed, individual information similar to a scent based identification card, covering identity, sex, reproductive status, and general health. It is a completely normal, essential part of how dogs introduce themselves to one another.
Why the rear specifically
Small glands located just inside the anus produce a highly individual scent unique to each dog, functioning almost like a signature, and because this scent is far more concentrated and specific than what can be picked up elsewhere on the body, rear sniffing gives dogs the fastest, most detailed introduction available to them.
A mutual, structured ritual
Two unfamiliar dogs meeting politely will often circle and take turns sniffing each other's rear rather than both pushing in at once, a small piece of etiquette that helps keep the greeting calm, and a dog that seems reluctant to allow this from another dog is showing a completely valid preference worth respecting.
Nothing to interrupt here
This greeting behavior is essential to normal canine social communication, and interrupting it too quickly can actually make a first meeting feel more rushed and tense than letting it run its natural, brief course.
Key takeaways
- Anal gland scent gives dogs detailed information similar to an identification card.
- This is the fastest, most concentrated introduction available to a dog's nose.
- Dogs meeting politely often take turns rather than both pushing in at once.
- Interrupting the greeting too early can make a first meeting feel more tense.