Every chinchilla owner knows that a chinchilla’s bones are delicate. You may have also heard that the issue specifically relates to the chinchilla’s rib cage. So, do chinchillas have skeletons, and if so, why do their bones break so easily?
Chinchillas have leg bones, spines, skulls, leg and foot bones and ribs like other mammals. Their bones are made from the same solid material as those in other animals, although they are mostly thin and flexible. Chinchillas do have a rib cage, not floating ribs, although much of the rib cage is cartilage so it is weak.
Because chinchillas’ bones can bend, fracture or break easily, correct handling guidelines must be followed. This will prevent unfortunate accidents. Everything you need to know about the chinchilla skeleton and how to deal with fractures, you can find below…
Do Chinchillas Have Bones?
Chinchillas are so delicate around the middle that they shouldn’t be held there. However, while delicate, chinchillas do still have bones. The bones are what gives a chinchilla its bodily structure, meaning it can walk, run and protect itself. Like other animals, chinchillas have:
- A skull, which is solid and thick to protect the brain and eyes
- Leg bones and paw bones to stand with
- Ribs, the purpose of which is to protect the vital organs (heart, lungs, liver, etc.)
- Tail bones which stretch out from the chinchilla’s behind, which are for balance when moving
These bones are essentially the same as those in other species of rodent. Take the paw, for example. A paper in the journal PeerJ compared the paws of chinchillas to those of other rodents. They have shortened thumbs, and have lost a toe through gradual evolution. But this is broadly similar to what has happened in other rodent species.
What this means is that chinchillas are little different to other rodents, except in certain specific ways.
Chinchilla Skeleton Diagram
As can be seen in the picture below, chinchillas have a normal-looking skeleton. From the outside, a chinchilla is instantly recognizable, but by looking only at its skeleton you could mistake a chinchilla for a large rat or squirrel.
The large skull and teeth, long tail and posture all mark this skeleton as one of a rodent, but it is indeed specifically a chinchilla. It appears far smaller because a chinchilla’s fur accounts for a large amount of its overall volume/size.
Do Chinchillas Have Spines?
Chinchillas are vertebrates. Vertebrates are animals which have spinal cords. The term comes from ‘vertebrae’, which is the name for the individual bones in the spine. You can see the spine running along the back of the skeleton in the diagram above.
The vertebrae protect the delicate spinal cord within. The spinal cord is what the animal uses to relay sensory inputs to the brain, and signals from the brain to the outer limbs to make them move. Without vertebrae to protect it, the spinal cord is easily damaged. Damage to the spinal cord can cause disability to limbs below the point of damage. You can feel a chinchilla’s spine through its fur when you handle it.
The tail is a continuation of the spine. It has the same structure of one vertebrae after the other as the spine does. Each vertebrae is smaller than the last as you approach the tail tip. The fact that the bones of the tail are the same as those in the core spine is reflected in their scientific name (caudal vertebrae).
Do Chinchillas Have Delicate Bones?
A chinchilla’s bones are no more delicate than those of other rodents. They are of the same thickness and density as those of other rodents, and are no more easy to break. What’s more likely to happen is for the bone to bend before breaking, in the same way that a wish bone will before it snaps.
The real reason why chinchillas are considered delicate is that all rodents are delicate. They are small, and are easily hurt by another animal as big and strong as a person.
Do Chinchillas Have a Rib Cage?
Chinchillas have ribs, like any other mammal. They also have rib cages, which is specifically defined as a formation which includes the spine, the ribs, and the sternum.
There is a myth that chinchillas do not have a rib cage or a sternum, and that they instead have ‘floating ribs’. Floating ribs are ribs that are not connected to a sternum or another rib at the front. This means they are more flexible, but cannot protect the organs as well.
This is not accurate. As you can see from the diagram above, chinchillas do have a sternum. You can see it on the opposite side of the rib cage to the spine. While the sternum is small and weak, it is nonetheless present, and the ribs are connected to it.
Besides that, the ribs themselves are highly flexible. This is because in most animals, the rib runs almost all the way from the spine to the sternum and is only connected by a small amount of cartilage. Cartilage is like bony muscle: stronger than regular muscle and weaker than bone, but more flexible than bone, too.
In a chinchilla’s rib cage, the cartilaginous section is as long as or longer than the rib. This means that the chinchilla’s rib cage is less strong but more flexible than usual. This is an important distinction, and is why you shouldn’t pick a chinchilla up by its middle. Its ribs don’t protect its organs as well as the ribs of other animals for this reason.
What Is a Floating Rib Cage, and Do Chinchillas Have One?
Chinchillas do have a sternum. Their ribs are attached to it by small muscles and cartilage, which is similar to other animals’ rib cages (including our own). You can see this in the diagram above. The bone of the rib is on the top half of the chinchilla’s body, and meets cartilage at its sides. You can see the meeting point where there is a small lump.
Chinchillas do have two floating ribs, one on each side. These are the lower-most ribs, towards the tail-end of the spine, and can be seen in the diagram above. Many other animals have a floating rib in the same place, including people.
However, despite this myth not being true, it is still true that you have to be careful when handling a chinchilla. It’s still true that:
- Chinchillas have thin ribs which can easily bend and break
- The cartilage which connects the ribs to the sternum is far longer than in other animals, which makes the cage more vulnerable to breaking, and more flexible
- A chinchilla’s ribs can poke into its organs if it is held around the middle
- A chinchilla’s spine is still delicate, and holding one around the middle can compress the spinal cord
This is why you have to pick up chinchillas according to long-established guidelines. To learn how to pick up a chinchilla by its tail rather than by its middle, read the linked guide.
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Can Chinchillas Break Their Bones?
A chinchilla’s bones are structurally the same as those of other animals. They are mostly bone marrow on the inside, with a solid exterior of bone. Larger parts of the bone, e.g. joints, are less dense on the inside, but are still strong.
Either way, because a chinchilla’s bones are structurally the same as those of other animals, they behave like those of other animals too. It’s possible for a chinchilla’s bones to bend, fracture or break. The younger the animal, the less chance of severe breaks.
These injuries heal over time. Bones have blood vessels inside them, like the rest of the body. These blood vessels supply oxygen, but also much-needed minerals to different parts of the body. When a bone breaks, this is what happens:
- In the few days after a fracture, a blood clot forms around the break. This both protects the break, and enables the blood to deliver minerals and oxygen more easily.
- Around the break and blood clot forms a callus. Callus is made of bone- and cartilage-material. This forms over the course of one to two weeks and keeps the bone in place, protecting it.
- The structure of the bone is rebuilt and reconnected. This means creating new blood vessels inside the bone, new bone material and new bone marrow.
- The callus is gradually re-absorbed by the body. With the bone reformed, it is no longer needed.
If the broken bone is not properly aligned, it takes longer to fill the gap. Infection is also more likely to occur as the wound takes longer to heal. If the bone is perfectly aligned, healing is much simpler.
Can You Accidentally Break a Chinchilla’s Bones?
It’s possible to accidentally break a chinchilla’s tail, spine or ribs through incorrect handling. New owners can easily pick their pets up by their middles without thinking. This can result in broken ribs and punctured organs, i.e. severe injury. You could also break your chinchilla’s bones by:
- Accidentally sitting on it
- Accidentally standing on it
- Closing the cage door on it or its tail with too much force
- Providing an unsuitable cage (your chinchilla can break its legs in the gaps of the floor)
- Dropping it from a great height (although chinchillas are capable of surviving jumps/falls as they can naturally jump up high)
- Mistreating it
Broken bones are made more possible by a lack of minerals. A lack of calcium in particular will result in weaker bones, especially if the lack occurs during development.
In this respect, a chinchilla is the same as any other pet. The only difference is that a chinchilla’s ribs are easier to break, as they are floating ribs. You must therefore be more careful when handling a chinchilla than you would with other pets.
How Long Do Chinchilla Bones Take to Heal?
Chinchilla bones do not take long to heal. They are thin and delicate, but this thinness also means they are easier to heal. Any breaks may have mostly healed between 7-10 days.
However, if you have ever broken a bone, you will know that there is a difference between initial recovery and long-term recovery. The break site may still cause you pain for a long period afterwards. It may also be susceptible to breaking again in the future. As such, do not assume that your pet’s broken bone has fully healed after this time.
What to Do If You Break Your Pet Chinchilla’s Bones
If your chinchilla has a broken bone, it needs medical attention. To determine what the issue is and get it fixed, follow these steps.
Observe Your Pet
Bone fractures have several obvious symptoms. Your pet will be in pain and struggle to move, and will experience swelling around the break site. It’s rare for there to be an open wound or bone poking through skin, but this is a possibility. This is similar to what fractures look like in other animals and people.
If you were there when the injury was sustained, you may have heard a cracking sound, which was the bone breaking. When your pet moves now you may hear a faint crackling noise. This is the sound of the broken ends of bone rubbing together.
Contact a Veterinarian
You should not leave your chinchilla to heal on its own. A veterinarian can diagnose and treat the fracture to make recovery quicker and more complete.
First, they will diagnose the problem. This is easy as the symptoms above are obvious enough to a novice, let alone a vet. But if the issue isn’t so clear cut, the vet will confirm the break with an X-ray. Once confirmed, the vet will do several things:
- Reduce the fracture, if it is a complete break, by realigning the bones
- Apply a bandage to the area to restrain movement, which is essential for fast healing
- Disinfect and dress any open wounds the chinchilla might have
- Prescribe antibiotics in the event of an open wound (to prevent infection, which can seriously complicate recovery)
- Prescribe mineral supplements (if the break was made possible by a lack of calcium)
Your vet may also advise you to do several things to prevent limb injuries in future and enable quick healing of your pet’s fracture. You should remove any platforms from your chinchilla’s enclosure until it’s fully healed, as jumping/falling would aggravate the issue. You must also avoid allowing your chinchilla free time in a pen or outside of its enclosure for the same reason.
Monitor Your Pet’s Condition
Keep an eye on your pet to see whether its broken bone heals correctly. Your pet shouldn’t gnaw at the site constantly, as this will interfere with recovery. It also shouldn’t overexert itself with too much exercise, so try to discourage this.
Once your pet’s condition has improved, you can return its enclosure back to normal. This means putting back in any platforms, elevated food bowls and so on that you had to remove. At this point, you may want to visit the vet again to ensure that the fracture has fully healed. If so, nothing further needs to be done: apart from being more careful in the future!
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