Rabbit Body Systems

Question 1

What structure occupies a large portion of the cranial thorax?
What is the clinical importance of the absence of septa between the lung lobes in the rabbit?
What type of breathers are rabbits? – what is therefore a concern to see a rabbit do? – what is this a sign of?

Answer 1

The thymus gland.
A pneumonia infection would not be localised to one lobe.
Obligate nasal breathers.
Open-mouth breathing.
A sign of severe respiratory distress.

Question 2

What does crepuscular mean?
Where does most digestion occur in the alimentary tract of the rabbit?
How do rabbits convert food to energy and use protein efficiently

Answer 2

Awake and eat at dusk and dawn.
Mostly occurs in the caecum and colon.
They make caecotrophs and eat them and perform browsing.

Question 3

What does high fibre stimulate?

Answer 3

Gut motility.

Question 4

What can occur when gut motility is low?

Answer 4

Over digestion of food –> Increase in lactic acid –> Lowered gut pH –> Affect gut microbes that digest fibre –> Change in microbial content of gut –> Damage to gut wall, gas build-up –> Toxin absorption into body –> Potential shock.

Question 5

Fibre excreted quickly or slowly?
What is the primary bacteria in the rabbit gut?

Answer 5

Quickly.
Bacteroides.

Question 6

How many lobes are there in the liver?
Gall bladder present in rabbits?
What is the clinical significance of the caudate lobe in the rabbit?

Answer 6

4-6 lobes.
Yes gall bladder present.
Caudate lobe in pedunculated (on a stalk) so there is risk of torsion of this lobe, affecting its blood supply.

Question 7

How much of the abdomen does the ileocaecocolic complex occupy?
What does the ileocaecocolic complex consist of?
What structures are attached to one another by a mesentery?

Answer 7

More than half of the abdomen.
Caecum and colon.
Descending duodenum, ileum, caecum, appendix, proximal colon, distal colon.

Question 8

What can cause gut stasis?

Answer 8

Stress (reduced PS NS activity), change to diet or inappropriate diet – low fibre, sugar/carbohydrate rich.

Question 9

What anatomical feature stops vomiting and eructating in rabbits?

Answer 9

A strong and well developed cardiac sphincter.

Question 10

What part of the stomach is glandular and which part is non-glandular?
What foreign material is commonly found in the stomach and why?
What structures of small intestine are present in the rabbit?

Answer 10

Cardia is non-glandular and the fundus is glandular.
Hair commonly found in stomach because of grooming behaviour.
Duodenum, jejunum and ileum.

Question 11

What is the name of the structure that the ileum expands into?
What is this structure composed of?
What other name is sometimes given to this structure?

Answer 11

Sacculus rotundus.
Composed of lymphoid tissue.
Caecal tonsil.

Question 12

What does the sacculus rotundus empty into?
What is this structure the junction of?
What structure does the caecum end in?
What does the weak ileocaecal valve do?

Answer 12

Ampulla caecalis coli.
Ileum, caecum and colon.
Caecum ends in the appendix.
Ileocaecal valve prevents backflow of ingesta into the ileum when the caecum contracts.

Question 13

What part of the abdomen does the rabbit large intestine occupy?
What process occurs in the caecum?
What is the primary microbe in the caecum?
Describe the caecal walls in rabbits – prone to what?

Answer 13

Most of the ventral floor.
Microbial fermentation.
Bacteroides.
Caecal walls are thin and friable – prone to dilation and potential rupture.

Question 14

What are the pockets in the caecum formed by?
How many parts can the caecum be divided into?
What type of appendix do rabbits have? – describe.
What tissue is the appendix made of?

Answer 14

Spiral constriction.
3 – divided into flexures.
Vermiform appendix – Worm-like.
Appendix composed of lymphoid tissue.

Question 15

What is the colon divided into?
What structure divides the 2 parts of the colon?

Answer 15

Proximal and distal colon.
Fusus coli.

Question 16

How can the proximal and distal colon be distinguished?

Answer 16

Proximal colon has taeniae and haustra whereas the distal colon does not.

Question 17

How many taenial bands are at the first section of the proximal colon and what other structures can be found here?
What do these other structures do?
How many taenial bands found at the second section of the proximal colon?

Answer 17

3 taenial bands are the first section of the proximal colon and wartzen present here too.
Wartzen increase surface area.
1 taenial band at the distal colon.

Question 18

What is the fusus coli equivalent to?
What does the fusus coli consist of?
What is the function of the fusus coli?
What process is the fusus coli important in?

Answer 18

Equivalent to third part of ascending colon.
Consists of thicken and highly innervated circular muscle.
Regulates passage of ingesta into distal colon, acting like a “pacemaker”.
Important in caecotrophy.

Question 19

What are the 3 types of colonic motility and describe their functions?
What stimulates the fusus coli?

Answer 19

Segmental contraction (like chopping up ingesta), haustral contraction (causes churning in the sacculations), Peristaltic/reverse peristaltic motility (moves ingesta along gut towards rectum/moves ingesta proximally).
Fiber stimulates it.

Question 20

What happens to the nutrient-rich liquid component in the rabbit GI tract?

Answer 20

It is sent back to the caecum to become caecotrophs.

Question 21

What is coprophagia?
Bacterial fermentation occurs in fore, mid or hind gut in rabbits?
Why is caecotrophy necessary?

Answer 21

When animals eat faeces.
Occurs in midgut.
Because the location of bacterial fermentation in the midgut means that nutrients (vits B and K) released from fermentation could be lost in the faeces so consumption of the faecal matter means it gets to pass through the alimentary tract again and be absorbed in the small intestine.

Question 22

At what age does caecotrophy begin to occur in the rabbit?
What do the rabbits do prior to this age?
What structure regulates colonic contraction?
What contraction types separate ingesta mechanically into solid and liquid in caecotrophy?

Answer 22

At 2-3 weeks of age.
Eat the caecotrophs of the adult to seed the gut bacteria.
Fusus coli regulates colonic contraction.
Segmental and haustral contractions.

Question 23

What are hard rabbit faeces made up of?
What happens to the liquid fraction of the ingesta?

Answer 23

Indigestible fibre.
Passes to periphery of haustra then returned by antiperistalsis to the caecum for further fermentation.

Question 24

What happens to the liquid fraction once in the caecum?
When does caecotrophy occur in the wild rabbit?
When does caecotrophy occur in pet rabbits, and why?

Answer 24

It undergoes further fermentation where it becomes more concentrated with nutrient overtime.
Occurs during the day while animal in burrow.
Occurs at night in pets as stimulated and eating during the day.

Question 25

What occurs in the caecotrophic phase?

Answer 25

1. Gut goes into a periodic change of motility.
2. The caecum contracts to expel soft paste into the proximal colon.
3. Digesta passes into the distal colon and moves through very rapidly due to fusus coli increases motility of the distal colon, meaning very little separation or water reabsorption.
4. Caecotrophs breach the anus and are moist.

Question 26

Why is it rare to see caecotrophs?
Are caecotrophs chewed once taken from the anus?
How are the caecotrophs protected from digestion in the stomach?
Where is the nutrients finally released and absorbed?

Answer 26

As they are eaten directly from the anus.
No, they are swallowed without mastication.
They are coated in mucus from the fusus coli.
Nutrients finally released and absorbed in the small intestine.

Question 27

What type of kidney is found un the rabbit? – what does this mean?
Describe the exterior of the rabbit kidney.
What can cause a red colour in the urine of rabbits?

Answer 27

Unipapillate – fused cortex which goes to a single point with 1 collecting calyx.
Smooth and bean shaped.
Porphyria or haematuria can cause red urine.

Question 28

What can porphyria be caused by?
What can haematuria be caused by?
How can porphyria and haematuria be differentiated from each other if rabbit presents with red-coloured urine?

Answer 28

Eating carrots.
UTIs, neoplasia, disease.
Urine dipsticks.

Question 29

Where in the genital tract does the urethra open onto?
Separate orifice for the opening of the urethra?
How can the sex of a rabbit be identified?
What castration should be performed on male rabbits and why?

Answer 29

The floor of the genital tract.
No separate orifice.
Apply pressure to the area to see if a penis can be extruded.
Closed castration as they have a very large inguinal canal and the subcutaneous scrotal sacs communicates freely with the abdomen through it. Closed castration will avoid the risk of herniation of some abdominal contents through into the scrotal sac.

Question 30

Describe rabbit testes.
What structure is immediately cranial to each testicle?
What structures are absent in the rabbit penis?
What can a male rabbit do to stop the sperm from another rabbit entering the female following the mating with him?

Answer 30

Long, horizontal and retractable.
Fat body.
Os penis and glans both absent.
Apply a copulatory plug in the female genital tract which is produced from the coagulatory glands.

Question 31

What accessory sex glands are found in the male rabbit?

Answer 31

Ampullae, vesicular gland, coagulating gland, prostate.

Question 32

What type of uterus does the female rabbit have and what does this mean?
What can interfere with the procedure when spaying a rabbit?

Answer 32

Duplex uterus – the two uterine horns have separate openings into the vagina so a double cervix.
The large amount of fat deposits around the broad ligament.

Question 33

What type of ovulators are female rabbits?
How long is the rabbit’s gestation period?
Comment on young.
What is a common hormonal condition in female rabbits?
What disease can be avoided by spaying female rabbits?
What type of placenta in the rabbit?

Answer 33

Induced ovulators.
31-32 days gestation.
Altricial young.
False pregnancies are common.
Uterine adenocarcinoma avoided by spaying.
Discoidal placenta.