Caudal vertebrae [Coccygeal] - Dog - General anatomy - Left lateral view - vet-Anatomy
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Caudal vertebrae [Coccygeal]

Vertebrae caudales [coccygeae]

Definition

Antoine Micheau

The caudal or coccygeal vertebrae are the vertebrae that follow the sacrum and form the bony base of the tail (the equivalent of the coccyx in humans).

They gradually decrease in size while becoming less complex in shape.

The number of caudal vertebrae differs between species:

Species/Group

Caudal Vertebrae Count

Human

3–5 (fused coccyx)

Dog

20–23

Cat

18–23

Horse

15–21

Cow

18–20

Pig

20–23

Elephant

26–33

Lizard

20–50+

Snake

20–40 (caudal)

Salamander

30–60

Bird (e.g., pigeon)

5–9 + pygostyle

Variation:

In carnivores and ruminants, they also possess two paramedian tubercles on the ventral surface of their body, called hemal processes. These processes can sometimes fuse, forming a hemal arch in which the median coccygeal artery rests.

References

  • Barone R. Anatomie comparée des mammifères domestiques, Tome 1, Ostéologie, 5th edition, Vigot, Paris, 2017.

  • Constantinescu GM, Schaller O. Illustrated veterinary anatomical nomenclature, 3rd Edition, Enke Verlag, Stuttgart, 2012.

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