Rabbits

What are some key features of a rabbits head

• Large erect or floppy pinnae

• Large protuberant eyes

• Cleft lip

• Twitchy nose

• Vibrissae

• Specialised dentition

What are the main features of rabbits ears

• Used for thermoregulation

• Funnel sound by rotating 270 degrees

• Used for administering medications and blood sampling

• Lots of blood vessels that are fragile and easily damaged

What are the main features of rabbits eyes

• Positioned laterally for a wide field of view

• Have a third eyelid

• Harderian gland which produces very stable tear film

• Single ventral lacrimal punctum draining into nasolacrimal duct

What are the most common causes of eye problems in rabbits

• Protuberant eyes mean higher risk of trauma

• Underlying dental disease

What will be noticed in an ophthalamic exam

• Merangiotic retina

• No tapetum

What is exopthalmos

When eyes become more protuberant looking

What causes exopthalmos

• Fright causing increase in blood pressure

• Diseased venous plexus

What ocular muscles are in their eyes

• Additional extraocular muscle the depressor palpabrae

• Rectus dorsalis

• Large retrobulbar venous sinus outside the extraocular muscles

What drains rabbits eyes

The external jugular

What are the features of rabbit dentition

• Hypsodont teeth

• Reserve crown

• Enamel extens below the gumline

• Aradicular and elodont so have open root or no true root

• Peg teeth

What is their dental formula

I 2/1 C0/0 P3/2 M 3/3

What is the sequence of events which leads to the development of chronic dental disease in rabbits

1. Dietary cause such as low fibre causing reduced tooth wear

2. Inadequate occlusal wear causes overgrowth of incisors, premolars and molars

3. Maloclussion develops which alters the bite and spurs form

4. Progressive elongation of teeth causes roots to elongate intp jaw bones

5. Causes pain and anorexia

Which features makes it difficult to examine the mouth of a conscious rabbit

• Small oral cavity

• Large tongue

• Narrow oropharynx

• Cheek folds

• Strong jaw muscles

• Stress and fragility

Why is it sensitive to touch a rabbits nose

• They have a blind spot so adaptations to compensate it

• Sensitive pads on nares

• Presence of vibrissae

What are the main features of a rabbits respiratory system

• Obligate nasal breathers

• Epiglottis rostral to soft pallate

• Nose twitches rapidly unless very relaxed

• 30-60 bpm respiratory rate

• Small thoracic cavity

• High chest wall compliance

• Low functional residual capacity

• Diaphragmatic contraction drives breathing

• Very sensitive to respiratory irritants

What is the structure of their lungs

• Right lobe has cranial, middle, causal and accessory lobes

• Left lung as cranial, middle and caudal lobes

• Thymus persists in the adult rabbit found in the cranial mediastinum

Why is intubating a rabbit challenging

• Long tongue

• Small glottis

• Narrow oropharynx

• Laryngospasm

What are the key cardiovascular parameters of rabbits

• Heart rate is 150-300 bpm

• Systolic blood pressure is 90-135 mmHg

• Total blood volume is 50-75 ml/kg

What are the venupuncture sites on rabbits

• Jugular

• Lateral saphenous

• Cephalic

• Marginal ear vein

What are the main features of their digestive system

• Hind gut fermenters

• Large stomach and huge caecum

• Highly efficient food converters

• WIll select concentrates over fibre

• Fibre essential for gut health

• Do have a gall bladder

What happens at the first stage of rabbit digestion

• Starts at the mouth

• Grinding action of the cheek teeth

• Strong tongue ensures all food is masticated prior to swallowing

What are the salivary glands

• Parotid

• Sublingual

• Zygomatic

• Mandibular

What is the oesophagus like

Three layers of striated muscle extending all the way to the cardia of the stomach

What is the stomach like

• Lies to left of midline

• Thin walled and J shaped

• Well developed cardiac sphincter prevents vomiting

What is the pH of rabbits stomach

• 1-2 so stomach and SI are practically sterile

• Neonates is 5-6.5

What is the small intestine like

• Accounts for 12% of digestive tract volume

• Secretes an enzyme called moltin

• Moltin stimulates motility in SI, colon and rectum but no effect on caesum

• Moltin is released in response to fat and inhibited by carbohydrate

What is the sacculus rotundus

Where the terminal ileum ends at the junction with the colon and caecum

What does the hindgut consist of

• Caecum

• Promimal colon

• Distal colon

What is the caecum like

• 40% of GI volume

• Ends in vermiform appendix

What is the proximal colon like

• 50cm

• Split into haustra sacculations, single haustra and fusus coli

• Terminal portion is fusus coli

What does the fusus coli do

• Regulated passage of ingesta into distal colon

• Seperates hard from soft faeces

What is the distal colon like

• 90 cm

• No sacculations

• Very long

What happens in hindgut fermentation

1. Microorganisms in the caecum perform fermentation producing VFA which absorb across the caecal wall

2. The bacteria replicate in the caecum forming a vital source of protein

3. Caecal contents are expelles as caecotrophs which are eaten from the anus

4. Caecal pellet protected from stomach by by mucus covering and bacterial replication continues

5. Digestion of caecel pellet delivers protein to animal

What controls gut motility

• ANS controls GI tract motility particularu the fusus coli

• Hormonal control by motilin and prostaglandin

• Presence of indigestible fibre in gut encourages motility and reduces caecal retention time

How are hard pellets produced

1. Contractions in proximal colon separate indigestable particles from liquid component

2. Indigestable contents move to centre of lumen and further water is absorbed

3. Hard pellets are produced

What are soft faeces formed

1. Smaller particles and liquid content move into peripheral lumen

2. Antiperistalysis returns them to caecum for further fermentation

3. Caecum contracts to expel soft contents into proximal colon which then move rapidly through distal colon with no further absorption

What are caecotrophs

• Produced about 8 hours post feeding

• Eaten directly from anus

• Provide source of protein, vitamin B and K

What discourages consumption of caecotrophs

High protein and low fibre

What encourages consumption of caecotrophs

High fibre and low protein

What is the reproductive capacity of rabbits

• Around 60 kits per year

• Can rebreed immediately after giving birth

What are the features of rabbits reproductive cycle

• Induced ovulators

• Ovulations occurs 10-13 hours after coitus

• Gestation length of 30-33 days

• Parturition lasts 30 minutes

What do kits eat

• Feed once or twice a day for 3-5 minutes at a time

• Maternal immunity is placental

• Start to take solid food around 18-21 days

What is the nutritional value of rabbit milk

• 13% Protein

• 9% fat

• 1% lactose

• 2.3% minerals

How are rabbits sexed

• Best sexed at weaning or later

• Should be double checked

• Males have no nipples

• Men have sccrotal sac and prepuce

What are the features of a rabbits penis

• Sits within rounded penile sheath

• Can be extruded using gentle digital pressure from 2 months old

• No os penis

What are the features of the scent glands

• Two hairless pockets seen either side of the urogenital area

• Often have hard and crusty material within

What are the features of the scrotal sacs

• Cranial to penis

• Large epidydimal fat pads

• Open inguinal canal meaning testes can be easily retracted into abdomen

What accessory sex glands do male rabbits have

• Seminal vesicles

• Prostate

• Paired bulbourethral glands

What are the features of the female reproductive system

• Duplex uterus

• Large saccular vagina

• Two cervices

• Long convuleted oviducts

• Mesometrium stores fat

• Uterus and ovarian pedicle

What happens in pseudopregnancy

• Caused by infertile mating or presence of a male

• Caused by secretion of progesterone from CL

• See enlarged mammary glands and abdomen

• May pluck belly and make a nest

• Regresses naturally but can reoccur multiple times

What are the features of their red blood cells

• HCT 33-35%

• RBC smaller then canine but larger then feline

• Anisocytosis and polychromasia and normal on a smear

• Lifespan of 57 days

What are the features of their white blood cells

• Lymphocyte is the most common circulating leucocyte

• Neutrophils called heterophils as cytoplasm stains pink-red

• Eosinophils have a bilobed nucleus and birght pink staining granuals

What is the rabbits vertebral formula

C7, T12, L7, S4, Cd16

WHat are the features of their musculoskeletal system

• Light and flexible

• Powerful epaxial and hindlimb muscles

• Tibail and fibula partially fused

• 5 digits of forelimb

• 4 digits on hindlimb

• No footpads

What are the three hair types

• Long guard hairs

• Short guard hairs

• Undercoat

What are the different fur types

• Satin

• Rex

• Wool

• Normal

What causes ulcerative pododermatitis

• No footpads

• Exacerbated by hard cage surfaces and unhygienic conditions

• More common in overweight animals or those with thin coat

Where are the scent glands

• Chin glands

• Inguinal glands

• Anal glands

What are the features of the kidneys

• Unipapillate

• Single medullary pyramid

How does rabbit calcium absorption differ from that of most other mammals

• It is passive and unregulated

• Absorb calcium directly in proportion to how much is in the diet

• Excess calcium is not blocked at the gut but instead excreted through the kidneys into urine as calcium carbonate crystals

• This is why rabbit urine can appear thick

What does normal urine look like

• From pale yellow to dark red

• Cloudy

• Colour is dietary dependent

What causes urolithiasis

Excessive prolonged dietary calcium intake

What is the normal pH of rabbits urine

• 8-9

• Because of insoluble calcium precipitates

• Can cause bladder and urinary stones