Canine GIT

Question 1

What requirements for canine nutrition change over time?

Answer 1

–Age
–Production stage
–Activity
–Health

Question 2

What are the dogs life stages?

Answer 2

• Neonate 0-2 wks
• Pediatric/Growth 2 wks–9/18 mo
• Adult 12 mo–7/9 yrs
• Geriatric 7/9 yrsonwards

Question 3

What is the purpose of the canine GIT?

Answer 3

•The dog is an omnivore (eats a variety of food of both plant and animal origin).
•The purpose of the digestive
–mechanically and chemically digestfood
–allow the absorptionof food
–assist the eliminationof solid waste
•Monogastric –‘simple stomached’

Question 4

What is the length and transit time of the GIT?

Answer 4

• The canine GIT is ~ 4-5 times the total body length of the dog
• Transit time 10-48 hours

Question 5

What factors influence transit speed?

Answer 5

diet
how many meals a day
exercise- increases speed
hormones
pregnancy

Question 6

What is the GIT made up of?

Answer 6

stomach
duodenum} small intestine
jejunum} small intestine
ileum} small intestine
caecum
colon
rectum
anal cavity

Question 7

What does the mouth do?

Answer 7

mechanically breaks down food

increases surface area so chemical digestion can take place

Question 8

What is the dogs dental formula?

Answer 8

Deciduous dental formula:
2 x (I3/3 C1/1 P3/3) = 28
Adult dental formula
2 x (I3/3 C1/1 P4/4 M2/3) = 42

Question 9

What is mastication?

Answer 9

adduction and abduction of the mandible

Question 10

What is saliva and what are its properties?

Answer 10

•Produced when food is present and in anticipation of food
•Saliva pH more alkaline than humans
•Purpose
–Lubricant
–Buffer
–No digestive enzyme activity

Question 11

What is the oesophagus?

Answer 11

• Role: To transport food from the mouth to the stomach
• Food spends only a few seconds here
• A muscular tube that transports the food into the stomach via peristalsis
• Cardiac sphincter can function as a two way valve

Question 12

What is the stomach?

Answer 12

• Very expandable
• Protein digestion starts here
• Stomach pH more acidic than in humans for digestion of bones and destruction of harmful bacteria
• Secretion of gastric juices regulated

Question 13

What does the stomach secrete?

Answer 13

• Protein-digesting enzymes (proteases)
• Pepsinogen
• Hydrochloric acid (HCl)
• Activates pepsinogen and creates right environment for enzymes
• Mucus
• Lubricates food and protects the lining of the stomach wall

Question 14

What does the small intestine do?

Answer 14

•Majority of digestion and absorption occurs here
•Longest part of GIT :-max digestion and absorption
•Large surface area
•Majority of protein, CHO and fat digested here
•Mechanical and chemical digestion
Duodenum approx. 25 cm
Ileum approx. last 15 cm

Question 15

What does the large intestine to?

Answer 15

• Caecum ~5cm
• Colon ~25cm
• The ascending colon
• The transverse colon
• The descending colon
• Rectum 5cm (anal canal ~1cm)
• No villi –surface area flat
• Some fermentation of dietary fibre by bacteria takes place
• Absorbs water and electrolytes
• Retention time: ~12 hours

Question 16

What accessory organs aid digestion but are not part of the GIT?

Answer 16

–Tongue
–Salivary glands (no amylase!)
–Pancreas
–Liver
–Gallbladder

Question 17

What are the incisors for?

Answer 17

cutting of food
grooming
single root

Question 18

What are canines for?

Answer 18

used for holding prey
fighting
hold tongue in place

Question 19

What are pre-molars for?

Answer 19

shear shaped
align with interdental space
break up food

Question 20

What are the molars for?

Answer 20

bite force between 300psi and 80000psi
biting food and breaking it up before swallowing
carnassial are the first lower molars and last upper molars
modified for shearing flesh

Question 21

What are hypsodont diet?

Answer 21

constantly emerging and growing teeth

Question 22

What is a brachydont?

Answer 22

teeth do not constantly grow