Differences between the dog and cat

Superficial pectoral muscle

both parts extend beyond the elbow and insert on the ulna in the cat in the dog they attach to the humerus

penile urethra

has a narrow diameter, smaller than the pelvic urethra clinically important since male cats often develop urethral blockages

extensor carpi radialis

has two distinct heads in the cat The long head originates from the lateral epicondylar crest of the humerus. The more substantial short head originates from the distal portion of the crest and the lateral epicondyle of the humerus.

dorsal elastic ligament

(present in all four feet) extend from the lateral side of the distal end of the middle phalanx to the dorsal part of the distal phalanx. These are also present in the dog and are easier to see in the larger species. However, in the cat, the retracted position of the distal phalanx is lateral to the middle phalanx, whereas in the dog the distal phalanx remains dorsal to P-2 in the retracted position. This is why cats, unlike dogs, can completely retract their claws and therefore walk with "silent paws." The same arrangement is present in the pelvic limb. (See Dyce Fig.16-9)

capsular vein

large vessel present on the external surface of the kidney

radial artery

larger than the distal continuation of the median artery As in the dog, the radial artery arises from the median artery in the distal third of the antebrachium. It passes deep to the tendon of the abductor pollicis longus and supplies the dorsal part of the paw.

medial saphenous vein

larger than the lateral saphenous vein and is commonly used for venipuncture. in dogs, the lateral saphenous vein is the larger vessel.

brachioradialis

more developed in the cat than in the dog, at times it is even absent in the dog It is a long, thin, flat muscle that originates on the lateral epicondylar crest of the humerus, crosses the flexor surface of the elbow and terminates on the medial surface of the distal radius. Its action is supination and it is innervated via the radial nerve.

biceps brachii

muscle terminates on the radius only in dogs it inserts on the radius and ulna with the brachialis

brachialis

muscle terminates on the ulna only in dogs it inserts on the radius and ulna with the biceps brachii

Short digital flexor

muscles are present as muscle bellies in the tendon of the superficial digital flexor m., distal to the tarsus. Much reduced short digital flexors are also present in the thoracic limb but they are very small.

cornified pines

on the free part of the penis in the mature intact animal

Projection of the heart

on the thoracic wall extends from the 4th intercostal space to the 7th rib (more caudal than in the dog).

cecum

only a short, comma-shaped diverticulum of the large intestine, as compared to that of the dog which is more capacious

supracondylar foramen

part of the humerus located proximally to the epicondyle unique to the cat the brachial artery and median nerve pass through this foramen on their way to the antebrachium; this could be significant in the case of a fracture of the humerus.

brachial artery

passes through the supracondylar foramen in cats

median nerve

passes through the supracondylar foramen in cats

caudofemoralis muscle (cranial crural abductor)

present in the cat A long thin muscle found between the biceps femoris and the superficial gluteal muscle; it inserts via an aponeurosis into the fascia lata and a thin tendon can be traced to the lateral side of the patella.

Soleus

present in the cat Basically this muscle is a third, laterally placed head of the gastrocnemius, found in cats, humans and goats, among other species. It originates from the head and proximal third of the fibula and its tendon joins with the gastrocnemius tendon, which inserts on the calcanean tuber. The tibial nerve innervates the soleus.

Short digital extensor

present in the cat There are three bellies, arising from proximal metatarsals III, IV and V. They insert on the tendons of the long digital extensors II, II and IV and assists in the extension of digits II, III and IV.

Supraspinous ligament

reduced in cats to a few elastic fibers that are difficult to see This may explain why cats are so adept ant extension and flexion of the spine.

metacromion

scapular process The distal part of the cervical trapezius inserts here and the omotransversarius originates here.

penis

short and directed caudoventrally in the non-erect state (note that when male cats urinate/spray, the urine is directed caudally)

In general, the long bones of the limbs (both thoracic and pelvic) are ___________ than those of the dog.

straighter

accessory pancreatic duct

the larger and more distally located in the duodenum of the dog is only present in 20% of cats

bulbourethral glands

they are located between the caudal edge of the urethralis muscle and the proximal commencement of the bulb of the penis.

glans penis

undivided and conical no os penis

Sartorius

undivided in the cat

Pancreatic duct

usually the only duct present in all cats

scrotum

ventral to the anus, covered with hair and not pendulous as in the dog

Clavicle

well developed in the cat, at least a cm long, can be palpated It is a rod shaped bone situated in the medial half of the tendinous intersection; it attaches to the sternum via a strong, fibrous ligament

coracoid process

well-developed projection of the scapula. It provides the origin for the coracobrachialis muscle, which is considerably larger in the cat than the dog.

In examination of the neck and thoracic region, you will notice a number of differences. Why is this?

Cats climb trees and use their paws/claws more in apprehending and holding onto prey.

supination

Cats possess a greater supination ability of the paws than dogs. If you ever watch a cat play with a toy or a mouse, you can see this greater ability to rotate the paw in action.

Supratrochlear foramen

Hole in the humerus, only found in dogs

deep digital flexor

The radial and ulnar heads of the deep digital flexor muscle are much larger in the cat than in the dog.

What is different visually about the pelvic limb skeleton in the cat compared to the dog?

You will notice that the femoral shaft is straight. The metatarsal bones are much longer (~2x) than the metacarpal bones. Unlike the dog, there is no sacrotuberous ligament.

Nuchal ligament

absent in cats

Omobrachial vein

absent in cats

cremaster muscle

absent in male cats present in dogs

sacrotuberous ligament

absent in the cat present in the dog

kidneys

are more pendulous than canine kidneys; that is to say, they hang down into the abdominal cavity more than those of the dog, which remain in close proximity to the body wall. They are also slightly more caudally positioned than in the dog--the right kidney is located opposite Vertebrae L2-L4, the left kidney opposite L3-L4.