CanineBiologyL3

• Body Size Range


  Chihuahua to Great Dane: 15cm - >100cm
• Body Weight Range


  <1 - >100 kg (Chihuahua - Mastiff)
• ME Requirements


  110 - 4,000 kcal/d
• Life Stages

  Growth (birth-approx 1 yr), adult (1-7 yrs), geriatric (7-death), gestation/lactation
• Gestation Period

  9 weeks (63 days)
• Weaning Age

  Between 6 & 8 weeks
• Puppy Characteristics

  Eye, coat, ear changes
• BWt vs. Life Expectancy

  Small size linked to longer lifespan
• Eruption of Permanent Teeth

  Incisors: 2-5 months, Canines: 5-6 months, Premolars: 4-6 months, Molars: 5-7 months
• Deciduous Teeth

  Begin to erupt at 21 days, replaced by permanent teeth at 4-6 months
• Incisors:


  Gnawing meat from bones and grooming
• Canines:


  Hold object in mouth, occasionally used at weapons
• Carnassials:


  Chewing - aided by tilting head, parts of these teeth laterally flattened to act as shears for tearing
• Premolars & molars:


  Adaptation for crushing and grinding, indication of more omnivorous dietary habits
• Brachycephalic:


  Short, strong head (e.g. Bulldog, Pekingese or Boston terrier)
• Mesaticephalic:


  Meaning skull of medium proportion (e.g. Setter, Beagle or German Shepherd), Nb. nearest to the ancestral wolf size
• Dolichocephalic:


  Long narrow head (e.g. Greyhound, Afghan or Whippet)
• Field of Vision


  Narrow head in dolichocephalic breeds for better balance & speed
• Withers Measurement

  Area from 1st - 9th thoracic vertebrae
• What does the forequarters consist of?

  Withers, scapula and length of humerus
• Front Types (proper structure)

  Straight front, out at the elbow, chippendale, east-west front
• Where's the dog's highest point of its height?

  Withers
• How are the forequarters attached to the dog body?

  Muscle only, scapula slides back and forth parallel to the rib cage
• Shoulder Angulation


  Slope of the shoulder with line parallel to the ground, desired 45-55° slope for optimal movement
• Hindquarters


  Pelvis, femur, tibia, tarsus, metatarsals for power
• Straight front:


  Forearms are straight, parallel to one another and positioned vertically to the ground
• Out at the elbow:

  Elbow turning out from the body as opposed to being held close
• Chippendale or fiddle front:

  Forelegs out at the elbows, pasterns close, and feet turned out
• East-west front:


  Incorrect positioning that causes the feet to turn outwards
• Bandy Legs


  Legs bending outward
• What's the desired structure in the hindquarters?

  Straight vertical line through the bones from pelvis, upper and lower thigh, pt of the hock down to the rear pastern and foot
• Cow-hocked


  Hocks turning in, rear feet toeing out
• Under-developed pelvis


  Pelvis fuses at 12 weeks in puppies
• Acetabulum


  Socket holding the femur's end
• Horizontal pelvic slope


  Determines backward reach & movement
• Centre of gravity

  Positioned closer to the front of the body
• Forequarters


  Hardest-working part supporting >50% weight, necessary so the hindquarters can be comparatively free to drive body forward
• How do dogs minimize lateral displacement?

  By attempting to single-track - brings its feet as close together as possible beneath the vertical center of gravity as it moves
• Gait


  Sequence of leg movements repeated cyclically
• What absorbs most of the concussion of each step?

  Forequarters