The anatomy of a cat rib cage is different than that of dogs and horses. First, you may raise the question – how many ribs does a cat have?
The number of the cat’s ribs is similar to the dog’s (26 ribs). Here, I will count the ribs from the cat’s axial skeleton and compare them with other animals.
Quick answer: cats have 26 ribs (13 pairs) in their axial skeleton. Among these ribs, the first 9 pairs are sternal, 3 are asternal, and the last 1 is floating.
I will also share the differences in the osteological features of the cat’s ribs from other animal’s ribs. You will also know the typical features of the cat rib cage with the labeled diagram.
So, let’s know the number and features of the cat’s ribs.
How many ribs does a cat have?
Ribs are the curved elongated bones arranged one after another from each right and left side of the vertebral column. If you want to count the ribs from the cat’s skeleton, you might have the following knowledge –
- A brief idea of the various bones from the cat’s axial skeleton,
- The boundary of the cat rib cage,
- Various types of ribs in the cat’s axial skeleton and
- A deep knowledge of – how to count the ribs from any animal,
The axial skeleton of the cats consists of head bones, various vertebrae, ribs, and sternum. You may know the details of these cat’s axial skeleton bones from the below-mentioned article –
- Cat skeleton anatomy with the labeled diagram – the bones from the axial and appendicular skeletons of the feline species,
You will also know the details of the boundary of the cat rib cage and the types of rib from this article. There are 3 major types of ribs (asternal, asternal, and floating) in the cat’s axial skeleton.
Let’s count the ribs from the below-mentioned labeled diagram of the cat’s axial skeleton –
I tried to show all the ribs from the cat’s axial skeleton in this diagram. So, you will find the following status of these ribs –
- Some ribs directly join to the sternum with their own cartilage, and the number is 9 pairs or 18,
- Few ribs indirectly join with sternum with others cartilage, and the number is 3 pairs or 6, and
- Finally, the last pair of ribs have no connection with the sternum,
So, the cat has 26 or 13 pairs of ribs in its axial skeleton.
How do you count the ribs from the cat’s rib cage?
You might count the cat’s ribs from the last where the floating rib is located. In the diagram, I have already mentioned the three types of ribs.
The last rib is counted as the thirteen rib, and the first rib is the first rib in the cats. Table 1 shows the total ribs count from the cat’s axial skeleton –
|Types of ribs||Cat’s Ribs Number|
|Sternal ribs||9 pairs or 18 ribs|
|Asternal ribs||3 pairs or 6 ribs|
|Floating rib||1 pair or 2 ribs|
|Total ribs in feline||13 pairs or 26 ribs|
Now, you will know the details of the cat rib cage with its unique features.
Where are the cat’s ribs?
The rib bones attach its dorsal end to the vertebral column and its ventral end to a cartilage. This is the costal cartilage that again attaches to the facets of the cat sternum.
The dorsal end of the feline ribs attaches from the last cervical vertebra to the last thoracic vertebra. Here, the first rib of a cat attaches with the oval facet from the bodies of the last cervical and first cervical vertebra.
Again, the distal or sternal end of this first rib attaches to the short costal cartilage. This short costal cartilage of the cat first rib directly attaches to the first facet of the sternum. Thus, the costal cartilage and sternum of the cats form the chondrosternal articulation.
The rest of the ribs of a feline attaches to the corresponding facet made by the vertebral bodies. Here, the diagram shows the location of the feline ribs in the thoracic or rib cage.
Cat rib cage
The cat rib cage is formed primarily by the ribs, costal cartilage, sternum, and vertebrae. The formation of the cat rib cage is similar to the dog’s rib cage.
Let’s find the detailed guide on the dog rib cage from the below-mentioned article –
How is the rib cage boundary formed in a cat? First, let’s identify the inlet and outlet of the cat rib cage –
An inlet of the cat’s thoracic or rib cage
- Dorsally – the caudal part of the last cervical vertebra and the first part of the first thoracic vertebra,
- Ventrally – the first of the cat sternum (manubrium) and
- Right and left laterally – the first rib bounds both the right and left lateral sides of the cat’s thoracic inlet,
Again, the outlet of the cat’s thoracic or rib cage
- Dorsally – the body of the last thoracic vertebra,
- Ventrally – xiphoid cartilage of the cat sternum and
- Right and left laterally – last rib and abdominal muscles,
Now, if you want to express the total boundary of the cat rib cage, you may tell as follows –
- Cranially and caudally – cranially, it is bounded by the thoracic inlet, whereas the caudally, with the thoracic outlet,
- Dorsally – you will find the bodies of the last cervical and all thoracic vertebrae,
- Ventrally – the sternum and its associated structures,
- Laterally – both the right and left lateral aspect of the cat rib cage is bounded by the serially arranged ribs,
You will also find the intercostal muscles, long and lateral thoracic muscles, vessels, and nerves in the cat rib cage.
Type of ribs in feline rib cage
The cat rib cage shows three types –
- Vertebrosternal or sternal ribs,
- Vertebrochondral or asternal ribs, and
- The vertebral ribs or floating ribs,
The distal end of ribs attaches individually to the sternal facets utilizing their cartilage. These ribs are the vertebrosternal or sternal ribs in the feline rib cage.
You will see significant variability in the costal cartilage of the last four pairs of rib. The distal end of three pairs of ribs attach to the sternum through cartilage to each other or the costal cartilage of the ninth ribs.
These are the vertebrochondral or asternal ribs of the feline rib cage. Finally, you will find one pair of exceptional ribs in the feline rib cage compared to the cows.
The last pair rib of the cat rib cage have no sternal attachment. It has only the vertebral attachment. Thus, this rib pair is known as the vertebral or floating rib in the cat rib cage.
Now, you will quickly understand the various types of ribs and count them from feline in different ways.
How many ribs does a cat have on each side?
What is the answer if I ask – how many ribs does a cat have on each side? The simple answer is that the cats have 13 ribs on each side of their thoracic or rib cage.
Let’s count the ribs from the right or left lateral side of the feline thoracic cage. You will find the following number from the right or lateral side of the feline rib cage –
- Vertebrosternal or sternal ribs = 9 (nine)
- Vertebrochondral or asternal ribs = 3 (three), and
- A vertebral rib or floating rib = 1 (one),
So, each side of the cat rib cage contains 13 ribs (thirteen).
What are the unique features of the cat’s ribs?
I will provide the unique features of the cat’s ribs that might help you to differentiate them from others. The unique features of the feline ribs are –
- There are 26 total ribs, where the first 18 are sternal, 6 are asternal, and the last 1 is floating,
- They are less curved than dog’s ribs but flattened rod-shaped structures,
- The appearance of the feline ribs is a little twisted compared to the dog’s ribs,
- You will see the head, neck, tuberculum, and angular process in their proximal extremity,
- The tuberculum is less prominent in the feline rib and gradually diminishes,
- The distance between the tubercle and head is less in feline ribs compared to other animal ribs,
- You will find a gradual increase in length from the first to ninth ribs and then decrease to the last,
- These ribs decrease in breadth behind the fifth number, and
- The length of the ninth and tenth ribs of a feline species are similar in the length,
You will also find a significant variation in the intercostal spaces of the feline ribs. The intercostal spaces of a cat rib cage gradually decrease from cranial to caudal.
The first rib of a cat is nearly in a dorsoventral position. But the other ribs have a slightly cranially directed dorsal end.
Cat rib anatomy
The cat rib is a flattened, curved, rod-shaped bone between the vertebrae and sternum. Among the thirteen pairs of ribs, the first four pairs have the typical feature.
The cat rib anatomy consists of the following –
- A proximal extremity that attaches to the vertebral bodies,
- The distal end that attaches to the costal cartilage and
- A curved, flattened rod-shaped body that possesses different surfaces, borders, and grooves,
Except for the length, the basic structures of these feline ribs are almost similar. So, let’s know the typical features of the body and extremities from a cat typical rib with a diagram.
First, I would like to show you the different features of the typical rib of a cat. Here, I showed you the structures of the body and extremities.
Following are the typical features of the cat rib’s proximal extremity –
- Expanded head or capitulum of the rib,
- Tuberculum with small facet,
- A neck between the capitulum and tuberculum,
- The angular process below the tuberculum, and
- Angle of the cat rib,
Again, the body of a cat’s typical ribs represent the following –
- Lateral and medial surfaces of the cat rib’s body,
- Cranial and caudal borders of the body, and
- Costal groove at the caudal border of the body,
From the distal extremity of a cat typical rib, you will find the following structures –
- The narrow ventral border of the distal end,
- Broad ventral surface, and
- Fecet for the costal cartilage on its distal end,
The labeled diagram identifies all these structures from the body and extremities of the cat rib. I have also provided more diagrams of the feline rib structure here.
The proximal extremity of the cat’s rib
Another name for the proximal extremity of the cat rib is the vertebral end. The head or capitulum is the globular part of the proximal extremity of the cat rib.
It articulates with the facet made by two adjacent thoracic vertebral bodies. The features of the cat’s thoracic vertebrae are similar to those of the dogs. Let’s get an idea of the features of the body of a cat or dog’s thoracic vertebrae from the below-mentioned article –
The tuberculum is the second large projection in the proximal end of the cat rib. It bears a smooth facet that articulates with the transverse process of the thoracic vertebra.
The tuberculum of the cat rib progressively decreases in antero-posteriorly prominence. You will not find the distinct tuberculum in the last two or three pairs of ribs.
Thus, these last three pairs of the feline ribs do not attach to the transverse process of the thoracic vertebrae.
The slightly constricted area between the capitulum and tubercle of the cat rib is the neck. Typically, the distance between the head and tubercle becomes gradually reduced in feline ribs.
Body of the cat rib anatomy with diagram
The body of the cat rib is a slightly flattened, curved, and rod-shaped structure. There is no clear demarcation between the body and proximal extremity of the cat rib.
However, the angle of the rib might provide an idea about the body and proximal portions. So, let’s know what the angle of a cat rib is.
The most convex part of the rib bone is known as the angle. This angle of the feline rib blends into the distal part, which is known as the body.
The angle of the rib is marked by a projecting process on its lateral border. This projecting process of the angle is the angular process. Within this process, you will find the ligaments of the feline ribs.
The body of each rib presents a convex lateral and a concave medial surface. Again, the body of the cat rib possesses a cranial and caudal border.
The borders of the feline rib are broad dorsally and narrow ventrally. In contrast, the surfaces of the cat rib are narrow dorsally and broad ventrally.
Due to the arrangement of the border and surface, it gives a twisted appearance.
The caudal border of each rib has the costal groove. No other unique features are present in a cat rib’s body.
The distal extremity of the feline rib
The distal extremity of the feline rib has a facet for articulating with the costal cartilage. You will see the narrower borders but broader surfaces in the distal end of the feline rib.
So, the most important feature of the distal extremity of the feline rib is costal cartilage.
What is the costal cartilage of the feline ribs?
The costal cartilage is the binding material that binds the ribs with the sternum. It articulates with the distal facet of each cat rib proximally and the sternal facet distally.
The first 9 pairs of ribs have their own costal cartilage that directly binds with the specific facet of the sternum. However, the last 4 pairs of ribs do not articulate directly with their cartilage to the sternum.
The costal cartilages of the 10th, eleventh, and twelveth ribs unite one another. They articulate with the sternal end together.
Thus, these three costal cartilages of these ribs form a common cartilage and insert commonly. The last or thirteen rib has the costal cartilage but does not attach to the sternum. Thus, the thirteen rib of a cat is the floating or vertebral rib.
What are the ligaments of the cat’s ribs?
Several ligaments in the cat rib attach various structures. Let’s see some of the important ligaments from the feline rib –
- A ligament in articular surfaces between the head of ribs and the body of the vertebrae,
- An articular capsule between the tuberculum and transverse process of the thoracic vertebrae and
- The small ligamentum bands between the tuberculum and neck of the rib to the transverse process of the thoracic vertebrae,
Frequently asked questions on cat rib’s number
Let’s enlist the frequently asked questions on the cat rib’s number with concise answers. But please go through the whole article to get the details of a cat rib.
How many ribs does a cat have in total?
Answer: the cat has 26 ribs total in its skeleton or thoracic cage. Both lateral sides of the cat’s thoracic cage possess 13 ribs. Thus, you will find 26 (twenty-six) ribs in total in a cat.
But many animals don’t possess 26 ribs. Let’s see the animals that have more or less number of ribs than the cats from Table 2 –
|Animals have more or less than 26 ribs||Number of ribs|
|Pig||28 or 30 ribs|
Do cats have a rib cage?
Answer: yes, cats have a rib cage that is formed by the ribs, vertebrae (last cervical and thoracic), and sternum. The diameter of the cranial inlet of the cat rib cage is elongated and less than the caudal outlet.
The diameter of the caudal outlet of the feline rib cage is more oval. You will see the diaphragm in the cat’s rib cage that differentiate the thoracic cavity from the thoracic part of the abdominal cavity.
Do cats have floating ribs?
Answer: yes, the cats have floating ribs. The last or thirteen rib pairs is the floating rib in a cat.
This is known as a floating rib, as it does not reach the sternum and has no connection with other ribs. Again, as this rib attaches only to the vertebral body, it is also known as the vertebral rib in a cat.
So, the answer to the question – how many ribs does a cat have was revealed. There are 26 ribs in the cat’s total on its thoracic or rib cage. Each side of the cat rib cage possesses 13 ribs.
The cat rib is a slightly flattened, curved, and rod-shaped structure with a slightly twisted appearance. Thus, you may easily differentiate the cat rib from other animals’ ribs with their external unique structure.