Thoracic radiographs —
canine vertebral heart scale (continued)

Step 3. Add the 2 vertebral measurements to yield the dog’s vertebral heart size.

  • Vertebral heart scale = long + short axis
  • Normal vertebral heart scale9 = 8.5–10.6

For some breeds, the normal range may be different. For example, the range is 10.3–12.6 for Boxers, 9.7–11.7 for Labrador Retrievers, 9.9–11.7 for Cavalier King Charles Spaniels, and 11.0–11.3 for Whippets.10–12

It is particularly important that, whenever a heart murmur is detected, a vertebral heart scale measurement be done on a lateral thoracic radiograph.

Click here to see radiographs of a normal and an enlarged heart as determined by vertebral heart scale.