The interactive dog atlas · Exterior and regions · Trunk

Lumbar region (loin) regio lumbalis

The loin is the portion of the back between the last rib and the pelvis. Beneath it are the lumbar vertebrae, which have no ribs, so the area is supported only by muscle.

Educational material, not a diagnostic tool. Written by the Mantrailing România team from veterinary sources we read. Updated 14.11.2026.

Dog in left lateral view — exterior, muscles, skeleton and organs Vector study after the Ellenberger, Baum and Dittrich plates: a standing dog, head to the left, deep chest and digitigrade limbs. The four layers use the same contour: exterior with body regions, superficial muscles, skeleton and organs.
  1. Lumbar region (loin)
  2. Back
  3. Croup
  4. Abdomen
Lumbar region (loin) on the atlas drawing, "Exterior and regions" layer, with the neighbouring structures. Left lateral view, after the Ellenberger, Baum and Dittrich plates.

Where it is

Between the last rib and the pelvis, on the upper part of the trunk.

System
Body regions
Region
Trunk

What it is and what it does

The loin is the portion of the back between the last rib and the pelvis. Beneath it lie the seven lumbar vertebrae, which have no ribs, so the region is supported only by muscle. Much of the spine's flexibility at the gallop comes from here, when the back arches and stretches.

Worth remembering

Much of the spine's flexibility at the gallop comes from here, when the back arches and stretches.

Names

  • Also called: loin, lumbar area.
  • Latin term: regio lumbalis.
  • In Romanian: Regiunea lombară (șalele) (Romanian page).

In the atlas lessons

Body regions: what is where (4 min):

The topline continues with the back, the loin (the lumbar region, with no ribs) and the croup, above the pelvis.

Walk, trot, pace, gallop (4 min):

The gallop: four beats with phases of suspension. Rotary: right hind, left hind, suspension, left fore, right fore, suspension; the dog's fastest gait. Transverse: the hind pair, then the front pair, a single suspension. The canter has three beats.

Guides it appears in