The cat scapula anatomy is a flat triangular bone with 2 surfaces, 3 borders, and 3 angles. You will see different important osteological features on the cat scapula bone’s surfaces, borders, and angles.
Quick summary of the cat’s scapula bone: there are right and left flat triangular scapulas in the fore limb of a cat. You will find 2 surfaces (lateral, medial), 3 borders (cranial, caudal, and dorsal), and 3 angles (cranial, caudal, and glenoid) in the scapula of cats.
Here, I will show you the essential osteological features of the right and left scapulas of the cat. You will know how to form the borders and angles in this scapula bone.
After completing this simple guide, you will identify the right scapular bone from the left one of the cat skeleton. Finally, you will quickly differentiate the cat’s scapular bone from the other’s species like ox, horse, dog, and pig.
Okay, let’s start to learn the osteological features of the cat’s scapula bone.
Cat scapula bone anatomy
The cat scapula, clavicle, and coracoid process form the thoracic or pectoral girdle. Among these bones, the scapula is the well-developed in the fore limb of cats.
First, let’s see the unique osteological features of the cat scapula anatomy –
- The spine of the cat scapula locates nearly in the middle and divides the lateral surface into two equal halves,
- You will find the typically convex cranial border, whereas the caudal border is more or less convex,
- The cranial angle in the cat scapula is practically absent,
- Spine of the cat scapula possess tuberosity, acromion process, and metaacromion process,
- Supraglenoid tubercle in a cat is small and blunt compared to dogs, horses, and ox,
- The coracoid process of the cat’s scapular bone is well-developed compared to the dogs,
- Again, the acromion process of the cat scapula is short, blunt, and extends at the level of the glenoid cavity,
- The glenoid cavity is less deep or shallow in the cat compared to dogs and horses,
- You will see the shallow subscapular fossa in the cat scapula with few rough lines,
But you will know the details of these features from the cat’s scapula with the labeled diagram.
Now, let’s see what you will learn from the scapula of the cats –
- Type and direction of the cat’s scapula bones,
- Surfaces, borders, and angles with their important osteological features,
- Muscles of the cat’s scapula,
- Other important structures like vessels and nerves in the cat’s scapula,
Finally, you will know how to differentiate the right and left scapula bones from the cat skeleton. However, you may learn the overview of every single bone from the cat skeleton from the below-mentioned article –
- Cat skeleton anatomy with labeled diagram,
Summary of the cat scapula bone
Before going to know the details anatomical facts of the scapular bone from the cat’s fore limb, you may know the summary from table 1 –
| Cat scapula anatomy | Features |
| Type of bone | Flat bone |
| Direction | Downward and forward direction |
| Surfaces | 2; Lateral and medial |
| Borders | 3; cranial, caudal, and dorsal |
| Angles | Cranial, caudal, and ventral |
| Lateral surface possess | Spine, supraspinous and infraspinous fossa |
| Medial surface has | Subscapular fossa, facies serrate |
| The spine of a cat’s scapula | Have acromion, metaacromion process, |
| Tuberosity of spine | Located in the middle of the spine |
| Glenoid angle | Ventrally, and possess a glenoid cavity. |
| Glenoid cavity | Shallow and have a glenoid notch |
| Supraglenoid tubercle | Small and blunt |
| Coracoid process | Larger and blunt |
| Acromion process | Short and blunt |
So, the above information is enough to understand the whole anatomical features of the cat’s scapula. Now, you will learn the details of these features with the labeled diagram from the next section of this article.
Cat scapula description
The scapula of a cat is a large, flat, and triangular bone that articulates with the femur. Its dorsal angle lies just ventral to the level of the spinous process (1) of the first or second thoracic vertebrae.
Again, the caudal angle of the cat scapula lies just opposite the ventral end of the spinous process of the sixth or seventh thoracic vertebrae. You will not find any direct articulation of the scapula with the axial skeleton of the cats.
This bone attaches to the axial skeleton with muscles and supports the trunk. In the outline of the cat scapula bone, it forms an imperfect triangular shape. So, you will find the following surfaces, borders, and angles in the cat scapula –
- Lateral and medial surfaces of the cat scapula,
- Cranial, caudal (axillary), and dorsal (vertebral) borders of the scapula, and
- Cranial (actually no cranial angle), caudal, and ventral (glenoid) angles of the scapula,
But you might know these surfaces, borders, and angles are formed in the scapula. As it is a triangular bone, it will form 2 large extended areas responsible for attaching the muscles.
Thus, you will see 2 surfaces – lateral (external) and medial (internal) surfaces in the scapular anatomy. When these surfaces meet at the cranial aspect of the bone, they will form the cranial border.
Again, the lateral and medial surfaces of the cat’s scapula meet at the caudal aspect; they will form the caudal border. Finally, these 2 surfaces of the scapula meet dorsally and form the vertebral or dorsal border.
When any 2 borders meet at a specific point, they form the angle. Here, you will find caudal and ventral angles in the cat scapula bone.
How is an angle formed in a cat’s scapula?
The cranial and caudal border meet at the ventral aspect and from the ventral angle in the scapula. In the case of a cat’s scapula bone, the ventral angle is also known as the glenoid angle, as this end contains the shallow glenoid cavity.
Again, the dorsal and caudal borders meet caudally; they form the caudal angle. Finally, the dorsal and cranial borders of the scapular bone meet at the cranial angle and form the cranial angle.
You will find the typical cranial angle in the case of dog, horse, and ox scapulas. But, here in the cat or feline scapulas, the dorsal or vertebral borders continue cranially and form the cranial border. Thus, you will not find the typical cranial angle in the feline scapula.
Now, let’s see the osteological features from the lateral and medial surfaces of the feline scapula bone with the labeled diagrams.
The lateral surface of cat or feline scapula
The most important osteological feature from the lateral surface of the cat scapula bone is the spine. And you know, the spine of the scapula is the elongated bony elevation that divides the lateral surface into two almost equal halves (or fossae) –
- The upper fossa is the supraspinous fossa and
- A lower fossa which is also known as the infraspinous fossa,
The spine of the feline scapular shows variation in its conformation or structure. From dorsal to ventral, the spine first show a sharp appearance. You will see the thick and rough raised area at the middle of the scapular spine.
This thick and rough area of the spine is known as the scapular tuberosity (or tuberosity of the spine). After the tuberosity of the spine, it shows the caudally projected, sharp-angled structure.
This caudally projected and sharp-angled structure of the spine is a metaacromion process. Again, the metaacromion process locates just dorsal to the acromion process of the feline scapula bone.
This metaacromion process is one of the unique features of the cat scapula bone anatomy. Now, the distal end of the cat scapula becomes slightly thickened and wide. This thickened distal end of the spine is known as the acromion process.
Anatomically, this acromion process of the cat’s scapular bone from the free and pointed end compared to the other animal’s acromion process. And you know, this acromion process of the feline scapula is located at the glenoid cavity level or supraglenoid tubercle.
You will also find the nutrient foramen at the distal end of the spine. Different muscles originate or insert in the different areas of the scapular spine.
Supraspinous and infraspinous fossae of the feline scapula
The supraspinous fossa is the anterior smooth and extended lateral surface of the cat scapula. Here, the cranial boundary of the supraspinous fossa is formed by the anterior border of the scapula.
Again, the caudal boundary of the supraspinous fossa is formed by the adjacent cranial surface of the spine. Here, the cranial border of the supraspinous fossa continues with the dorsal surface.
The middle part of the cranial border of the supraspinous fossa is wide and provides a convex appearance. The distal end of the cranial border shows the notch (known as the scapular notch).
A supraspinatus muscle of the cat scapula arises from the supraspinous fossa. But, from the distal end of the supraspinous fossa, you will find the origin of the infraspinatus muscle.
Like the dog scapula, you will also find the almost triangular-shaped caudal infraspinous fossa in the cat scapula. The infraspinous fossa is more deep compared to the supraspinous fossa.
Here, you will find a few lines at the distal end of the supraspinous fossa. Again, there are few nutrient foramina at the distal end of this supraspinous fossa.
The adjacent caudal part of the scapular spine forms the cranial boundary of the supraspinous fossa of the cat scapula bone. Again, the caudal boundary is formed by the caudal border of the scapula bone.
You will find only the origin of the infraspinatus muscle from the infraspinous fossa of the feline scapula.
The medial or costal surface of the cat scapula bone
The medial surface of the cat scapula bone represents deep depression compared to the lateral surface. This medial surface of the feline scapula lies opposite the first 4 – 5 ribs and the adjacent thoracic vertebrae.
As the medial surface of the feline scapula lies opposite the ribs, it is also known as the costal surface. In the medial or costal surface of the cat’s scapula, you will find the below-mentioned features –
- A deep, depressed area is known as the subscapular fossa,
- Two triangular areas on the proximal extremity (known as facies serrate), and
- Few rough lines on the medial surface of the feline scapula,
At the midline of the subscapular fossa, you will find a faint bony elongated elevation (just opposite to the lateral spine). Again, you will find two rough lines on the cranial aspect of the medial surface.
These two oblique and rough lines indicate the obvious landmark for muscle attachment. You will also see the caudal lines at the posterior margin of the medial surface.
There are variable numbers of nutrient foramina in the medial surface of the feline scapular bone. The subscapularis muscle arises from the subscapular fossa on the medial aspect of the feline scapula bone.
Again, the serratus ventralis muscle of the cat also arises from the facies serrate of the medial surface. In the labeled diagram, you will find all of these important features from the coastal surface of the cat’s scapula bone.
Borders of cat scapula bone anatomy
The cranial borders of the cat scapula bone are curved and thin. It forms a convex appearance in the middle.
You will find the rough and thickened area at the beginning of the cranial border (proximally). Again, this cranial border becomes smooth and thick at the distal end.
As well as at this distal end, the cranial border also forms the notch, which is known as the scapular notch. Here, you will find some rough lines and nutrient foramina in the distal end of the cranial border.
The dorsal border is also curved and also termed the vertebral border. This vertebral border of the feline scapula continues cranially as the cranial border. Again, this same border continues caudally as the caudal or axillary border of the scapula.
You will find a narrow band of scapular cartilage on the dorsal border of the cat scapula. This scapular cartilage of the feline scapula represents the unossified part of this bone.
In the dorsal border of the feline scapula, you will find the insertion of the rhomboideus muscle.
The caudal border of the cat scapula is thick and almost straight in the feline. But, in the case of dog scapula, the caudal border forms the concavity.
You will find other different osteological features from the dog scapula in the below-mentioned article on anatomy learner –
- Dog scapula anatomy – features of scapular bone and muscles
At the distal part of the caudal border, you will also find the infraglenoid tubercle. The cat scapula’s tubercle is thicker than those of the caudal border.
The essential muscles that arise or insert on the different borders of the feline scapula will be discussed in the next section of this article.
Angles of cat scapula anatomy
The dorsal and caudal borders form the caudal angle of the feline scapula. This border of the cat scapula anatomy is comparatively thinner, rough, and slightly curved.
You will find the origin of the teres major muscle from the caudal angle of the cat scapular bone. Again, a part of this teres major muscle also arises from the caudal border of the cat’s scapular bone.
The cranial angle is curved and formed by the union of cranial and convex dorsal borders. This angle of the feline scapula is generally more convex and thicker than others.
You will not find any muscle that directly originates or insert on the cranial angle of the feline scapular bone.
Now, the ventral angle of the feline scapula is formed by the ventral union of cranial and caudal borders. Another name for this ventral angle of the cat scapular bone is an articular, glenoid, and lateral angle.
Important features of the glenoid angle
This ventral or glenoid angle of the cat scapular bone is important as this angle possesses the articular surface. This is an oval depression known as the glenoid cavity and articulates with the head of the humerus bone.
The glenoid cavity of the feline scapula is shallow compared to other species like the ox, horses, and pigs. You will find the laterally flattened border in the glenoid cavity or fossa of the cat’s scapular bone.
The glenoid notch of the cat or feline scapular bone is less developed compared to the other animal species. At the cranio-dorsal aspect of the glenoid cavity, you will find the largest tuberosity of the scapula.
And the largest tuberosity of the cat scapula is supraglenoid tuberosity. This tuberosity project cranially and has a medial inclination.
You will find a small beak-like projection that extends from the medial aspect of the supraglenoid tubercle of the scapula. This beak-like projection of the cat scapula is the coracoid process.
This coracoid process of the cat’s scapular bone is more developed compared to the dogs and ox. You know the coracoid process of the feline scapula bone is the remnant of coracoid bone.
You may learn more about the anatomical features of the ox scapula from the article mentioned below –
- Scapula of ox – the ultimate guide to learning the scapular anatomy of the animal,
From this coracoid process of the cat scapula, the coracobrachialis muscle arises. Again, the tendon of the biceps brachii muscle arises from the supraglenoid tuberosity of the feline scapula.
Cat clavicle bone anatomy
In most cursorial mammals, the clavicle is drastically reduced bone. This reduced clavicle bone is often embedded into the shoulder muscles.
“You will learn the shoulder muscles that arise or insect on the different parts of the feline scapula in the next section.”
This reduced clavicle is the slender, rod-like, and curved bone in the cat. You will find the slightly enlarger sternal end in the cat clavicle bone.
This bone medially articulates with the manubrium of the sternum bone. Again, the clavicle laterally attaches to the acromion process of the scapula bone.
Cat scapula muscles anatomy
Different muscles in a cat’s shoulder region have a direct or indirect connection with the scapula bone. First, let’s try to identify the following muscles from the scapular bone of a cat.
Here, in table 2, I will provide the name of the muscles that have origin or insection on the scapula bone of the cat –
| Muscles in cat scapula | Origin or insection in scapula |
| Supraspinous muscle | The entire surface of the supraspinous fossa |
| Infraspinous muscle | Airses from infraspinous fossa |
| Teres major muscle | Arises from the distal third of the axillary border |
| Levator scapulae ventralis muscle | Insert ventral border of metaacromion process and also in infraspinous fossa. |
| Acromiodeltoid muscle | Originates from the acromion process of the scapula |
| Spinodeltoid muscle | Arises from the spine of the scapula |
| Teres major muscle | Arises from the axillary border of the scapula |
| Coracobrachialis muscle | Arises from the large coracoid process of the scapula |
| Biceps brachii muscle | Arises from the tendon above the glenoid cavity |
| The long head of triceps brachii | Originates near the glenoid fossa of the axillary border of the cat scapula |
| Subscapularis muscle | Arises from entrie subscapular fossa |
All these muscles that have a direct origin or insertion on the different areas of a scapula are identified in the labeled diagram. Now, you will learn more about these muscles that are provided in table 2 with a diagram.
Supraspinatus muscle in cat scapula
This is one of the thick muscles in the cat scapular bone that lies in the supraspinous fossa. The supraspinatus muscle arises from the entire surface of the supraspinous fossa of the cat scapula bone.
This muscle inserts on the greater tuberosity of the humerus bone. The main function (action) of the cat’s supraspinatus muscle is to protract the humerus bone.
If you want to learn the osteological features of the animal’s humerus bone, you may read the below-mentioned articles –
- Dog humerus bone anatomy with the labeled diagram, and
- Humerus of ox – the complete guide to learning humerus bone anatomy,
But, the osteological facts of the cat humerus bone are somewhat different than these of the humerus bone. So, you may follow the anatomy learner’s special guide on the cat humerus bone.
Infraspinatus and subscapularis muscles of a cat
Here, the infraspinatus is thick and smaller compared to the supraspinatus muscle in the cat. This muscle arises from the surface of the infraspinous fossa of the cat scapula.
Again, the infraspinatus muscle inserts on the lateral surface of the greater tuberosity of the cat humerus bone. The main action of the infraspinatus muscle is to rotate the cat’s humerus bone laterally.
On the other hand, the subscapualris muscle of a cat is a larger, medial triangular muscle. This triangular muscle locates on the medial surface of the cat’s scapula (or in the subscapular fossa).
The subscapualris muscle of the cat arises from the entire surface of the subscapular fossa. Again, it inserts on the dorsal border of the lesser tuberosity of the cat’s humerus bone.
The main action of the cat’s subscapualris muscle is to adduct the humerus bone.
Teres major and minor muscles in the cat scapula bone
The teres major is the thick and triangular muscle on the caudal or axillary border of the cat’s scapula bone. You may easily identify the teres major muscle from the infraspinatus muscle.
Here, the teres major muscle of a cat arises from the dorsal third of the axillary or caudal border of the scapula bone. This triangular muscle of the cat’s scapula bone is inserted on the medial surface of the humeral shaft.
The tendon comes from the latissimus dorsi muscle attached to the tendon of the teres major muscle and forms the common tendon. This common tendon of these two muscles inserts on the shaft of the cat humerus bone.
On the other hand, the teres minor muscle of the cat scapula anatomy is small and somewhat triangular. This teres minor muscle locates between the infraspinatus and the long head of the cat’s triceps brachii muscles.
This teres minor muscle arises from the axillary or caudal border near the glenoid fossa of the cat scapula. Again, you will see the insertion of this teres minor muscle on the greater tuberosity of the humerus bone.
This teres minor muscle has a synergistic action with the infraspinatus muscle. Both these teres minor and infraspinatus muscles rotate the humerus bone laterally.
Levator scapulae ventralis muscle in the cat
This is a band-like muscle in the scapula of a cat. The cranial end of this levator scapulae ventralis muscle emerges from the clavotrapezius muscle.
You will see this levator muscle in between the clavotrapezius and acromitrapezius muscles. This muscle of the cat scapula arises from the two heads from the ventral surface of the atlas and tympanic bulla.
Again, the levator scapulae ventralis muscle inserts into the followings –
- One head insert onto the ventral border of the metaacromion process of the cat’s scapula, and
- Another head inserts into the infraspinous fossa of the cat’s scapular bone,
This levator scapulae ventralis muscle of the cat pull the scapula bone cranially.
Acromiodeltoid and spinodeltoid muscle of cat scapula
The acromiodeltoid is the flat muscle in the cat scapula that lies ventral to the levator scapulae ventralis muscle. From the acromion process of the cat’s scapula bone, this acromiodeltoid muscle arises.
Again, this muscle is inserted on the surface of the spinodeltoid muscle of the cat scapular bone. The main action of the spinodeltoid muscle is to flex the humerus and rotate this bone laterally.
Again, the spinodeltoid muscle lies ventral to the acrominotrapezius and levator scapulae ventralis muscles. At the caudal aspect of the spinodeltoid muscle, you will find the acromiodeltoid muscle.
From the spine of the cat’s scapular bone, this spinodeltoid muscle arises. Again, the insertion of this muscle is on the deltoid ridge of the humerus bone.
This spinodeltoid muscle also has a synergistic action with the acromiondeltoid muscle. So, together they will perform flexion of the humeral bone as well as the outward rotation.
Coracobrachialis and biceps brachii in cat scapula bone
The coracobrachialis is the short and band-like muscle in the medial aspect of the shoulder joint of cats. The cat’s coracobrachialis muscle arises from the scapula’s coracoid process.
It inserts on the proximal end of the cat’s humeral bone. And the main action of this coracobrachialis muscle is to adduct the humerus bone.
On the other hand, the biceps brachii is the thick muscle on the cranial surface of the cat’s humerus bone. This cat muscle arises from the tendon above the glenoid fossa of the scapula.
It forms a tendon that inserts on the radial tuberosity of the cat’s radius bone. Again, this muscle has a synergistic action with the brachialis muscle.
The triceps brachii is the very large and lateral muscle of the cat, but only the long head arises from the glenoid fossa of the scapula bone. The tendon from this triceps brachii insert on the surface of the olecranon process of the ulna bone and extends the forearm.
Cat scapula labeled diagram
Now, you will see every single osteological feature from the cat scapula bone with the labeled diagram. Here, I will show you the osteological features from both lateral and medial surfaces.
First, let’s see the lateral surface of the cat or feline scapular bone, where I tried to show you the spine, the tuberosity of the spine, the metaacromion process, and the acromion process. Again, the labeled diagram on the cat scapula lateral surface identified the supraspinous and infraspinous fossa.
From the medial or costal surface of the cat scapula bone, the subscapular fossa, along with the muscular lines and facies serrate, are also identified in the labeled diagram.
Here, the labeled diagram also identifies the cranial, caudal, and dorsal border of the cat scapula. Again, the cat scapula labeled diagram also identifies the caudal and ventral angles.
The diagram also shows the different features from the ventral or glenoid angle of the cat scapula bone. Here, the shallow glenoid cavity, glenoid notch, supraglenoid tubercle, infraglenoid tubercle, and coracoid process are also identified in the cat scapula labeled diagram.
You may find more diagrams of the feline scapula on social media of anatomy learners. Now, let’s compare the ox, horse, pig, and cat scapular bones in the next section of the article.
Comparison of cat scapula with ox, horse, and pig
You will find a little variation in the cat scapula compared to other species’ scapulae. Here, I will provide the little difference among the ox, horse, pig, dog, and cat scapulas in table 3 –
| Comparative study of the scapula | Scapula features in different species |
| Cat scapula bone | The spine divides the lateral surface into equal halves, Have metaacromion process, The acromion process locates at the level of the glenoid cavity, Coracoid process – beak-like and larger |
| Ox scapula bone | More triangular and spine divide a lateral surface into unequal halves No metaacromion process, The acromion process locates above the glenoid cavity Coracoid process – not developed |
| Horse scapula bone | Roughly triangular, and the spine divides the lateral surface into unequal halves. There is no metaacromion process No acromion process, The coracoid process is well-developed, |
| Dog scapula bone | The spine divides the lateral surface into two halves, No metaacromion process in dog scapula, The acromion process is blunt, A coracoid process is smaller compared to cats |
| Pig scapula bone | Have a wide spine that divides the lateral surface into nearly two halves, No metaacromion process in pig scapula bone, An acromion process is rudimentary in pig scapula, The coracoid process is small |
But, you may learn more about these scapulas from different species like the ox, horse, pig, and dog from the special articles of anatomy learner. So, from the discussion, you got the major difference in the cat scapula bone with the metaacromion process.
Again, the spine of the scapula bone, the cranial angle, and the glenoid angle possess some exceptional appearance compared to the other species’ scapula bone.
How to identify the right and left scapula from the cat’s limbs?
To identify the right or left scapula bones from the cat’s limbs or skeleton, you might know the details and features of it. Now, you may consider a landmark to identify the lateral or medial surface of the cat scapula bone.
Suppose you may consider the following landmarks to differentiate the right scapula from the left –
- A lateral surface possesses a spine that divides the lateral surface into two halves,
- The cranial border of the scapula is concave, whereas the caudal border is roughly straight, and
- The dorsal border of the cat scapula is convex, whereas the ventral angle possesses the glenoid cavity,
Now, let’s see the diagram where I tried to show – how you may identify the left scapula from the cats.
Frequently asked questions on cat scapula anatomy
In this section, you will find the questions on the cat scapula bone anatomy with their concise answer. These questions are enlisted here based on the learners’ inquiries on the feline scapula.
But, it is always recommended to learn the full scapular osteological features from this article. Okay, now, let’s see the questions on the cat scapula bone with their concise answer –
What is a scapula on a cat?
A scapula is a flat and triangular bone in the cat’s fore limb. The cat scapula is a triangular and flat bone with 2 surfaces, 3 borders, and 3 angles.
The cat’s scapular bone forms the shoulder joint with the humerus. Here, the shallow glenoid cavity of the cat’s scapula articulates with the circular and smooth head of the humerus bone.
Again, on the lateral and medial aspect of the cat’s scapula, you will see different muscles that directly arise from it or insert on it.
Where is the scapula on a cat?
The scapula on a cat lies on the ventral end of the spinous process of the thoracic vertebrae. It forms the thoracic or pectoral girdle in the cat and has a close relationship with the ribs of the thoracic cage.
The cranial angle of the cat’s scapular bone lies opposite to the thoracic vertebrae’s second or third spinous process. In comparison, the caudal end lies ventral and opposite to the sixth or seventh thoracic spinous process.
Again, the direction is downward and forward, which I have already described in this article.
Do cats have scapulas?
Yes, cats have 2 scapulas in their limbs. The anatomical features of both right and left scapulas are similar in cats or any other species.
But, you might identify the right or left scapular bone from the cat’s thoracic and pelvic limbs. For this, you need to know the details description of the cat’s scapular bone with the proper diagrams.
What is the function of the scapula?
The main function of the cat scapula is to support the thoracic cage and the body. Again, different muscles in the scapula perform various functions in their forelimbs.
You will find the functions of these muscles attached to the cat scapula bone that were described previously.
Conclusion
So, the cat scapula bone anatomy differs slightly from that of dogs, horses, and ox. The metaacromion and beak-like coracoid processes are two major exceptional osteological features in the cat scapula bone.
Now, you may identify the different features of the cat scapula bone with the real sample. You will also differentiate the right scapular bone from the left scapula of the cats.
