table

• Vertebral formula for different animals:

  • Dog: C7T13L7S3Cd20-23
  • Horse: C7T18L6S5Cd15-21
  • Ruminants: L: C7T13L6S5Cd18-20, S: C7T13L6S4Cd16-18
  • Pig: C7T14-15L6-7S4CD20-23
• Atlas differences:

  • Dog: Alar foramen is absent, instead there is an alar notch
  • Horse: Has 3 foramina - intervertebral, alar, and transverse
  • Ruminants: Transverse process is absent
  • Pig: Lateral vertebral foramen is divided into two
• Axis differences:

  • Dog: Long with dens typically tooth-like
  • Horse: Long with bifed spinous process
  • Ruminants: Long with spout-shaped dens
  • Pig: Short with high spine directed, 6th cervical vertebra
• Lumbar vertebrae:

  • Transverse process of L4-6 articulate with each other
• Sacral vertebrae:

  • Spinal processes are fused to form a median sacral crest
• Ribs differences:

  • Dog: Cylindrical shaft with 13 rib pairs
  • Horse: Narrow shaft with 18 rib pairs
  • Ruminants: Strongly curved ribs in dorsal third with 13 rib pairs
  • Pig: Wide, flat shaft with long neck and 14 rib pairs
• Scapula differences:

  • Dog: Spine bisects the lateral surface into equal halves
  • Horse: Trapezius tubercle is present, distinctly triangular
  • Ruminants: Trapezius tubercle prominently overhangs the infraspinous fossa
  • Pig: Tuber of the spine is well developed
• Humerus differences:

  • Dog: Intertuberal groove is single and undivided
  • Horse: Intertuberal groove is divided
  • Ruminants: Intertuberal groove has a well-developed sagittal ridge
  • Pig: Intertuberal groove is divided with a low sagittal ridge
• Radius and Ulna differences:

  • Dog: Two bones are separated, neck of the radius is distinct
  • Horse: Ulna fused 2/3 down to radius, radius and ulna connected by a dense connective tissue
  • Ruminants: Ulna fused by ossification, ulna is complete
  • Pig: Ulna not necessarily fused and extremely slender
• Carpal Bones differences:

  • Dog: Radial bone sometimes fused with intermediate carpal bone
  • Horse: Radial bone present
  • Ruminants: Radial bone present
  • Pig: Radial bone present
• Metacarpal Bones differences:

  • Dog: Metacarpal bones 1,2,3,4 and 5
  • Horse: Metacarpal bones 2, 3 and 4
  • Ruminants: Metacarpal bones 3, 4 and 5
  • Pig: Metacarpal bones 2, 3, 4, and 5
• Digits differences:

  • Dog: Digits 1, 2, 3, 4, 5 = 5
  • Horse: Digits 3 = 1
  • Ruminants: Digits 2, 3, 4, 5 = 4
  • Pig: Digits 2, 3, 4, 5 = 4
• Digits of Dog, Horse, Ruminants, and Pig:

  • Each has 3 phalanges
  • Digits 3 and 4 have 3 phalanges
• Skull, Mandible, and Hyoid apparatus:

  • Hyoid Bone features Basihyoid, Epihyoid, and ligamentum epihyoidium
  • Mandible includes Prominent mandibular angle, Diastema, and Coronoid process
  • Skull shows Rostral bone, Facial crest, Facial tuberosity, and Paranasal sinuses with variations in size
• Syndesmology:

  • Nuchal ligament differs among Dog, Horse, Ruminants, and Pig
  • Distal sesamoidean ligaments are important in the stay apparatus
• Myology:

  • Cutaneous muscles of the head and neck vary in presence and development among Dog, Horse, Ruminants, and Pig
  • Facial muscles like Levator nasolabialis and Masseter differ in importance and structure
• Muscles of the Thoracic region:

  • Muscles of the Pectoral girdle and shoulder joint vary in presence and structure among Dog, Horse, Ruminants, and Pig
  • Muscles of the elbow, radioulnar, carpal, and digits show variations in presence and function
• Tendon divides into 3 and inserts in digits 3, 4, and 5
• Extensor policis longus and indicus are present but rudimentary
• Long flexors of the digits in different animals:

  • Dog: tendon divided into 4 (cats 5)
  • Horse: undivided tendon of insertion
  • Ruminants: very tendinous, provided with an accessory
  • Pig: tendon divided into 2
• Short muscles of the digits in different animals:

  • Dog: interossei muscular
  • Horse: ligamentous, known as suspensory ligament
  • Ruminants: ligamentous, known as suspensory ligament
  • Pig: muscular
• • Pig: biceps femoris has short and long (vertebral) heads
• Muscles of the pelvic limb:

  • Muscles of the pelvic girdle:
  • Dog: iliopsoas with two components not separated
  • Horse: psoas major and iliacus
  • Ruminants: psoas major and iliacus
  • Pig: psoas major and iliacus
  • Intrinsic muscles of the pelvic limb:
  • Muscles of the hip joint:
  • Dog: gluteus superficialis is a separate muscle connected to tensor fascia lata
  • Horse: gluteus superficialis fused with biceps femoris
  • Ruminants: gluteus superficialis fused with biceps femoris
  • Pig: gluteus superficialis fused with biceps femoris
  • Muscles of the buttocks:
  • Dog: biceps femoris has short (ischiatic) head only
  • Horse: biceps femoris has short and long (vertebral) heads
  • Ruminants: biceps femoris has short and long (vertebral) heads
• Stomach classification:

  • Dog, Horse, Ruminants, Pig
  • Simple stomach lined with entirely glandular epithelium
  • Complex stomach in Ruminants with 4 compartments: rumen, reticulum, omasum, and abomasum
• The stomach fundus is very extensive, has a blind sac called saccus caecus, and a diverticulum known as the gastric diverticulum
• The intestines in Dog, Horse, Ruminants, and Pig have different characteristics in the jejunum, cecum, and colon
• Accessory glands like the liver and pancreas in Dog, Horse, Ruminants, and Pig have variations in their structure and presence of ducts
• Respiratory system differences in the nose, nasal cavity, trachea, and lungs of Dog, Horse, Ruminants, and Pig
• Urinary system variations in the kidney and urethra of Dog, Horse, Ruminants, and Pig
• Reproductive system variances in the male and female reproductive organs of Dog, Horse, Ruminants, and Pig
• Near the pelvic inlet lies the mesovarium
• Uterine horns are straight, have a wide lumen, and form 2 tightly wound spirals
• The body of the uterus is short, relatively large, and about as long as a horse
• The cervix is short, with internal and external uterine orifices lying close together
• The vagina serves as a receptacle for seminal fluid
• The vestibule's floor has the entrance to the suburethral diverticulum
• Labia are rounded, often pigmented, covered more or less densely with hair
• Placentation can be zonary deciduate, diffuse non-deciduate, or cotyledonary non-deciduate
• Mammary glands can have different numbers of glands and teats with varying numbers of canals
• In the cardiovascular system, the heart in different animals has variations in the number of bones in the aortic orifice