How much to feed
How can I tell if my dog is underweight?
Last updated 23 September 2026 · How we write and check this
Short answer
If you can easily see individual ribs, the spine, or hip bones without needing to touch your dog, and there is little to no muscle covering over the ribs and hips, your dog is likely underweight. A healthy weight dog should have ribs you can feel but not clearly see, with a smooth, rounded muscle covering rather than a bony, angular appearance.
Visual and hands on signs
Visible ribs, spine, or hip bones from a normal viewing distance, without needing to look closely or touch the dog, are a clear sign of being underweight for most breeds, aside from naturally lean breeds like sighthounds where some rib visibility is normal.
Running your hands along the sides, you should feel a thin but present layer of muscle and a small amount of fat over the ribs, rather than bone with almost nothing covering it.
Other things to check alongside weight
Look at overall energy and coat condition too, since a genuinely underweight dog often has a dull coat and lower energy alongside the visible weight loss, whereas a naturally lean breed with visible ribs but good energy and coat condition is more likely just a lean build.
Compare against how your dog looked at a time you know was healthy, using photos if helpful, since body shape memory can be unreliable over months.
What to do next
See your vet promptly if your dog has lost weight without an obvious cause, such as a deliberate reduction in food, since sudden or unexplained weight loss can have several underlying causes worth ruling out.
If your dog is naturally lean or recently rescued and underweight from a known cause, your vet can help set a safe, gradual weight gain plan rather than a large immediate increase in food.
Key takeaways
- Easily visible ribs, spine, or hip bones without touching are signs of being underweight in most breeds.
- A healthy weight dog has ribs you can feel but not clearly see, under a thin muscle and fat covering.
- Dull coat and low energy alongside visible weight loss point more strongly toward a genuine problem.
- Unexplained weight loss is worth a prompt vet visit rather than assuming it will resolve on its own.