Whether you were the type of kid who was fascinated by anatomy in Biology class and whether the very idea of dissection makes you squeamish, there’s no denying that rabbits have interesting bodies. From their long ears to their twitching noses, how adorable they look when waddling along to their incredible speed while hopping full tilt, rabbits are interesting from top to bottom.
If you’re a bit more biology and anatomy-minded, however, you might wonder how rabbits are able to accomplish all of this. With that in mind, let’s take a closer look at some of the more interesting factoids about rabbits’ chests, ribs, bodies, and what’s at the heart of their physical capabilities.
On Rabbit’s Ribs
To answer our titular question, rabbits have 24 ribs, arranged in 12 pairs. The first seven of these are typically known as “true sets,” because the rib pairs are attached together with costal cartilage. The other ribs are not attached, and are thus known as “false sets.” (If that sounds a lot like how humans’ ribs are laid out, that’s because it is, and anatomical similarities like that are one reason why rabbits are sometimes still used in biology class dissections.) The last two sets of ribs, the 11th and 12th pair, are also not attached to the sternum, leading to their nickname of “floating ribs.” There is no cartilage connecting these bones, with them instead being attached to the spinal vertebra area. This lack of connection between them also makes this the most fragile part of a rabbit’s ribcage.
Additional Rabbit Skeleton Facts
Rabbits have 222 bones overall, with their ribcage accounting for 11% of that overall bone total. In total, there are 23 types of rabbit bones, including:
- The cranium (which is itself at the center of evolutionary morphology studies)
- The scapula
- The spine (with a rabbit’s vertebral column being made up of 45 vertebrae broken down into five categories: caudal, cervical, lumbar, sacral, and thoracic.)
- The fibula, tibia, and femur in their legs
Slightly more than half of a rabbit’s skeleton is made up of marrow. Two-thirds of this marrow is located in its flat bones, with the remaining one-third in long bones.
Rabbits’ skeletons are lighter and less tense than those of slightly larger domestic mammals such as cats, making up only 7% to 8% of a rabbit’s total body mass. What’s more, rabbit skeletons are a lot more fragile than feline skeletons, which makes it that much more important to handle your rabbits with care. You should never place rabbits on a surface from which they may be at danger of falling from a great height. In addition, you should never squeeze them through a tight space, as this can cause dislocated limbs, broken backs, and any number of other injuries.
Like us, rabbits need to keep their bones strong, ribs included. A broken bone can be incredibly painful and, in the wild, potentially fatal as it would interfere with their ability to hop away quickly without pain, making them easy prey for predators. It is thus extraordinarily important for rabbits to consume enough calcium to keep their bones in good shape.
Fruits that contain a fair amount of calcium per serving size (in this case 3.5 oz) include:
- Kiwi (34 mg)
- Oranges (43 mg)
- Dried apricots (55 mg)
- Rhubarb stalks (143 mg)
In addition, vegetables that are rich in calcium include broccoli, okra, and lettuce, while parsley and alfalfa are good choices for herbs.
On the flip side, one sign that your rabbit may not have enough vitamin D – another key component in keeping your rabbits’ bones strong – is tooth trouble. If you see your rabbit’s teeth coming out or becoming uneven, it may be a sign of bone growth problems. A lack of calcium and exercise can also lead to osteoporosis and weakening bones that way. What’s more, not only can a Vitamin D deficiency lead to bone growth problems, but it can also leave them with a weaker immune system as well, making them that much more susceptible to disease.
Keeping Your Rabbit in Shape
Just as important to making sure your rabbit’s diet with respect to good bone health is how much exercise it gets. If a rabbit does not exercise and build up strength, it can start to experience severe bone weakness. Rabbits’ own hind legs can sometimes be so powerful as to hurt their back or damage their bones if they are not in shape. In fact, young rabbits who don’t get enough exercise can be susceptible to experiencing bone weakness and broken bones not only in their youth, but as they start to get older. After all, with old age often comes bone-weakening conditions such as osteoporosis and arthritis. That’s true of humans, and it’s certainly true of rabbits, making it all the more important that you make sure your rabbit can build up bone strength while it can.
Let your rabbit out when possible and allow it to hop around a bit. Give it treat incentives for exercising or eating foods that are rich in calcium. Do your best to try and balance your rabbit’s different dietary needs.
If your rabbit does suffer a broken bone, especially a broken rib, you will want to take it to the vet immediately. You’ll want to be extremely careful when picking it up. Not only is your rabbit likely to be in a great deal of pain, but it is already extremely fragile, so you don’t want to risk accidentally pressing the broken bone against its internal organs or otherwise causing it more pain.
If you can feel your rabbit’s ribs too easily, you’ll want to feed it a bit more and ensure that it is not underfed. On the flip side, if you can’t feel its ribs at all, but only ribs of fat, chances are your rabbit is obese.
Thankfully, as long as you keep your rabbit’s bones sturdy and keep it active and healthy, your rabbit should remain in good shape, ribs and all, for years to come.