Title: Anatomy and Physiology of Cats and Dogs
1Anatomy and Physiology of Cats and Dogs
- Differences Between the Species
- Part 3
2Differences in Cats and Dogs
- Cats
- skeleton has 245 bones
- Skull has large eye sockets (why?)
- Jaw is short and strong (why?)
- 26 teeth as kittens and 30 as adults
- Limited ability to grind food
- Dogs
- skeleton has 319 bones
- 3 types of skulls dolichocephalic, mesocephalic,
and brachycephalic - 28 teeth teeth as puppies and 42 as adults
- More teeth allows for crushing and grinding of
meat and plant material
3Dog Skull Types
4Dog Skull Types
- Dolichocephalic
- Sight hounds
- Wolfs cranium elongated
- Narrow, long snout
5Dog Skull Types
- Mesocephalic
- Scent hounds and pointers
- Wolfs skull shortened with broader snouts to
accommodate larger nasal chambers
6Dog Skull Types
- Brachycephalic
- Boxers, bully breeds, Cavalier, Pug
- Short, compact skulls that often lead to health
problems
7Brachycephalic Skull Health Problems
The change in the skull shape of the British
Bulldog over the last fifty years. Notice
particularly the extreme for-shortening of the
nasal cavity. Image courtesy of Natural History
Museum, Bern
8Brachycephalic Skull Health Problems
- Skin with shorter skulls, the skin folds over
itself around the eyes and nose which trap
moisture and lead to bacteria growth
9Brachycephalic Skull Health Problems
- Eyes - a flat skull causes the eye sockets to
become shallow, which leads to the eyes
protruding. The cornea is more exposed, causing
it to become dry and more likely to become
damaged
10Brachycephalic Skull Health Problems
- Respiratory
- as the skull shortens over time due to poor
breeding practices, the amount of soft tissue in
the nose and throat remains the same. - soft tissues are all crammed into a smaller space
combined with the lack of underlying nasal bones,
causes the nostrils to become very - this crowding inside the nose and back of the
throat obstructs airflow - Brachycephalic Upper Airway Obstructive Syndrome
(BUAOS)
11Brachycephalic Skull Health Problems
- Syringomyelia (SM) / "neck scratcher's disease"
- fluid-filled cavities develop within the spinal
cord near the brain
12Brachycephalic Skull Health Problems
- the back half of the Cavalier King Charles
Spaniels skull is too small to accommodate all
of the brains cerebellum, which may also be too
large, and so it squeezes through the foramen
magnum (hole in back of skull) partially
blocking the flow of CSF down the spinal cord
13Brachycephalic Skull Health Problems
- Syringomyelia (continued)
- the pressure created by the abnormal flow of CSF
is believed to create the SM cavities (syrinx)
in the spinal cord - Incredibly painful disease
- Up to 95 of all Cavilier King Charles Spaniels
affected by the mutation over 50 have SM - https//www.youtube.com/watch?vfDjxvgfUVRU
14The Feline Spine
- The shoulder blade is attached to the rest of the
body only by muscles, not by bone - gives shoulder blade freedom to twist and move
- allows cats to open gait for full speed (30 mph)
- small collarbones allow cats to squeeze through
tight openings and land on their feet from
various heights
15Cat Righting Reflex
- A vestibular apparatus in their inner ear acts as
a balance and orientation guide - The flexible backbone and the absence of a true
collarbone allows the cat to right itself in the
air by twisting its head around
16Cat Righting Reflex
- Cats have a built-in parachute (low
body-volume-to-weight ratio) - When falling, this allows them to slow their
velocity by spreading out and becoming their own
parachute (What other animal can do this?) - https//www.youtube.com/watch?vRtWbpyjJqrUlistU
U6107grRI4m0o2-emgoDnAAindex0featureplcp
17Cat Righting Reflex
- Data of cats falling from windows in tall
buildings was collected by veterinarians in New
York City - 90 survived, but with some injuries
- Of those, over a third needed life-saving
treatment - Cats that fell from 7-32 stories were less likely
to die than those that fell from 2-6 stories
(WHY?)
18Cat Righting Reflex
- One thought is that after a certain distance a
cat reaches maximum speed and the vestibular
mechanism in the ear shuts off, causing the cat
to relax (Why is relaxing important?) - Another thought is that the greater height gives
the cat time to change to its parachute position