Rabbits Flashcards
State some features of normal rabbit head anatomy and reasons why these benefit the animal
Large pinnae- good for sound tunnels and thermoreg
They have central Auricular veins and marginal veins on their ears
Large lateral protuberant eyes- wide field (both above good as prey species)
Cleft lip
They have a well developed 3rd eyelid and harderian gland which produces a lipid component- these things allow the rabbit not to blink for a long time
They have a large retrobulbar venous plexus outside Extraocular mus
There teeth continous grow
They have lots of tissue in cheeks
How do the feature in the head predispose to problems
The large retrobulbar venous plexus needs to be avoided when doing an enucleation. It also causes eyes to push out if BP is too high.
The fact that the eyes are protuberant gives a risk to trauma
Continuously growing teeth/tooth root issues close to nasolacrimal duct and the eyes means risk of infection and injury. Dental disease is also very common due to overgrowth.
How could you flush the nasolacrimal duct
Via star shaped lacrimal punctum
What does merangiotic retina mean?
BVs in one region only
They are horizontal running in the rabbit
Are the rabbits Extraocular muscles the same as the dog
No they have an extra one. The depressor palpebrae
Which Extraocular muscle can be easily located and help you to stabilise the eye during surgery
Rectus dorsalis
Which vein drains the eye
If this is ligated by accident what could this cause?
Jugular vein
Exophthalmos= abnormal eyeball protrusion
Give the dental formula of a rabbit
I2/2, c0/0, pm3/2, m3/3
The second lot of incisors are called peg teeth
Give 3 words used to describe rabbit teeth
Aradicular Hyposodont (crown longer) Elodont (cont growing)
Describe the respiratory system of the rabbit
They are obligate nasal breathers
They have a long tongue, small glottis, and large cheeks
They are prone to laryngeal spasm (sens to irritants)
They have a small thoracic cavity compared to the size of the abdominal cavity
They have high chest wall compliance
They have a low functional residual capacity (little air in lungs at end of expiration)
There diaphragm controls breathing
They have 3 lobes on the left (compared to rodents-1,ferrets-2)
They have 4 on the right (same as most rodents and ferrets)
Describe the rabbits cardiovascular system
They have a very high HR 150-300bpm
BP=90-135mmHg
Total blood vol= 50-75ml
They have little collateral circulation- this means if the coronary arteries or cerebral arteries (to brain) are blocked then there’s no other means of getting blood there. Damage/ligation/repeat catheterisation causes exophthalmos
The jugular has no anastomoses to the internal jugular like in the dog. Remember the jugular drains the head including the eye
Blood from: marginal ear vein, Cephalic, jugular, saphenous
Ferrets have 5 pairs of salivary glands, how many does a rabbit have?
4 pairs = parotid, sublingual, zygomatic and mandibular. They have NO molar.
They release salivary amylase in response to food in their mouth
What kind of muscle is the rabbits oesph made from?
All striated muscle!!!
Same as dogs, cattle and sheep
Cats horses and humans have striated cranially and smooth caudally!!!
How do rabbits differ from a horse in terms of GI? Even though they are both hindgut fermenters!
The rabbits DOES have a gall bladder, the horse doesn’t
Describe the anatomy of the rabbit GI tract
Oral cavity grinding cheek teeth and large tongue allows all food to be masticated before swallowed , 3 layers of striated muscle oesphag, well developed cardiac sphincter so NO vomitting (cf ferrets who can), large J shaped stomach, small intestine, ileocolic valve known as sacculus rotundus (caceal tonsil) before HUGE caecum (blind ended sac with vermiform appendage), into colon.
Why is fibre essential?
For gut and dental health
Rabbits will select concentrate instead (
What is the pH of the rabbits stomach and SI, what does this mean?
1-2
Means practically sterile
What happens with neonates in terms of developing this pH?
Neonates have a pH of about 5-6.5
Milk oil is produced between 0-6 weeks which acidifies the stomach contents and prevents bacterial growth. When the neonate starts to eat caecotrophs, the hindgut begins to get populated with Normal flora (from 2 weeks)
What enzyme does the SI secreted and what does this do..
It secretes motilin
This stimulates motility in the small intestine, colon and rectum
What reduces this secretion?
What increases it.,
High carbohydrates reduces
High fats increases
Describe the rabbit colon
The proximal colon is roughly 50cm. It has 3 subsections. The first section has 3 haustra and taeniae. The second section has 1 haustrum 1 taeniae. The final section is called the fusus coli. This section has no haustrae. The final part regulates passage of food into the distal colon. It therefore separates soft and hard faeces.
The distal colon has no sacculations and is very long (around 90cm)
Describe hindgut fermentation in the rabbit
In the caecum, microorganisms particularly bacteriodes spp. Perform fermentation and produce VFAs.
These absorb across the caecal wall.
The bacteria proliferate in the caecum. The bacteria themselves are a vital source of protein.
Caecal contents are expelled as caecotrophs and are eaten from the anus.
The caecotrophs are protected from the stomach acid by a mucus layer.
The protein (bacteria)can then be absorbed in the SI
What does prostaglandin do to gut motility?
It decreases proximal colon motility
But increases distal colon motility
What thing controls motility particularly the fusus coli?
The PNS
What else encourages motility and reduces caecal retention time
Presence of indigestible fibre (cellulose and lignin)
This is why fibre is so essential in the diet. It prevents gut stasis which is often fatal in a rabbit
Where are hard pellets produced and how!
In the proximal colon.
Contractions move indigestible parts to the centre of the lumen and liquid component to the edges to allow absorption. This produces hard faeces
How do soft faeces form
Small particles and liquid component to edges of proximal colon. Anti peristalsis returns particles to the caecum for further fermentation.
Caecum expels them as soft faeces into the proximal colon. They move rapidly through the distal colon without any further absorption
What are caecotrophs a good source of?
Protein, Vit B and vit K
What encourages caecotroph consumption?
High fibre and low protein diet
Vice versa
Give some facts about rabbit reproduction
Reach maturity at 16 weeks Receptive every 5-6 days Gestation 30-33 days Produce 1-8 kits Have post partum oestrus
When do rabbits ovulate?
They are reflex ovulators
They ovulate 10-13 after coitus
Are rabbits altricial or precocial?
They are altricial. They require maternal care.
Compared to guinea pigs which are precocial
What is parturition called in a rabbit?
Kindling
There is rarely any dystocia, parturition takes about 30 mins
Why are hand reared neonates prone to mortality?
This is not due to lack of MDA because transfer is via the placenta
Instead it is due to lack of milk oil which acidifies the stomach and prevents bacteria. This is needed until a bacteria population has been established.
How does rabbit milk compare to dog/cat?
It’s higher fat, protein and calories. It has a high nutrient value
This is why kits feed once daily for 3-5 mins
Give some facts about the male reproductive anatomy of a rabbit
They have no os penis
Penis can be retracted from 2 months
They have 2 hairless pockets either side of the penis= scent glands often containing crust
Scrotal sacs are cranial to the penis.
They have large epididymal fat pads
They have an open inguinal canal meaning testes are easily retracted into abdomen: care during castrate
From what age can you castrate a rabbit
3 months
Males fight otherwise
Describe the female reproductive anatomy
Duplex uterus compared to a mammal which has bicornate/gpigs reportedly have both
They have a large sac like vagina followed by 2 cervixes, 1 for each horn. They have long convoluted oviducts.
The uterus and ovarian pedicals are very friable.
The mesometrium stores fat
Can rabbits have false pregnancies!
Yes!!
They are caused by infertile makings or presence of a male. Caused by secretion of progesterone from CL.
Clinical signs= plucking belly to make a nest. Enlarged mammary glands and abdomen.
Usually resolves on its own but can occur many times
Normal rabbit blood smear results=
- RBC smaller than canine but larger than feline
- anisocytosis and polychromasia normal
- lymphocyte is most common (cf dog: neutrophil)
- neutrophils are heterophils as cystoplasm stains pink, they are hard to differentiate from eos
What does anisocytosis and polychromasia mean?
Anisocytosis = unequal size RBC
POLYCHROMIA= high numbers of immature RBC
What does living inside, little exposure to sunlight and a poor diet predispose a rabbit to?
Fractures and oesteoporosis
Their skeleton is extremely lightweight and flexible
How does the vertebral column differ in a rabbit from a dog!
12 thoracic
4 sacral
What makes rabbits be able to produce an extremely strong kick?
Large epaxial and hindlimb muscles
How many digits on forelimbs and hindlimbs?
What is different about the tib and fib compared to a dog!
5 front 4 back (toes to hock on ground)
Tib and fib partially fused
Which part of the vertebrae is common for fractures
L6-7
What 3 types of hairs do rabbits have?
How often do they moult?
Where are they hairless!
Long guard hairs
Short guard hairs
Undercoat
Moult twice a year (head downwards)
Nose, scrotum, inguinal area
Why are hard cages and unhygienic conditions not good for rabbits! Relate this to their anatomy
This is because they have furry feet with no footpads and so hard surfaces e,g. Wire cages and unhygienic conditions can predispose to ulcerations and pododermatisis. This is always why you should keep your rabbit in a good BCS- obesity can also cause these injuries
How many sets of scent glands do both male and female rabbits have?
3 sets
Inguinal, submental (under chin) and anal.
This is why you see rabbits rubbing there faces on things
Why is metabolism of calcium unusual in rabbits and why is his important?
Mammals control the amount of absorbed calcium from the diet according to need. Rabbits however absorb it all and get rid of excess via kidneys. Blood levels therefore reflects the amount in diet.
Prolonged excessive dietary calcium can result in excessive calcium carbonate being excreted which predisposes to the formation of urine stones.
How would you describe rabbit kidneys?
Is rabbit urine acidic or alkali?
What colour is it usually?
What colour would it be with a high calcium diet?
Unipapillate
Ph= 8-9 (alkali)
Colour varies from pale yellow to red depending on diet.
A thick creamy urine is produced from a high calcium diet
How many faecal pellets does a rabbit produce each day?
150
Do both male and female have nipples?
No females only
How to urethers differ in male and female rabbits?
Males drain into bladder lower down on neck of bladder
What’s the tidal volume of a rabbit?
How do you calc min volume?
4-6ml
MV= TV x RR
Do adult rabbits have a thymus? Do dogs?
Yes
Dogs regress
Which way does the males penis point?
Caudally
How many kinks are there in the nasolacrimal duct?
What are these called?
2
Proximal maxillary bend
Distal incisor tooth bend
