10. Rabbit Biology and Models

How many chromosome does rabbit have?

Diploid Chromosome #: 44

What metabolic feature makes the rabbit a suitable model for atherosclerosis research?

Unable to increase sterol excretion in response to a high-cholesterol diet, leading to hypercholesterolemia

Scientific name for New Zealand white rabbit or dutch belted rabbit?

Oryctolagus cuniculus

Scientific genus for cottontail rabbits?

Sylvilagus

Scientific genus for true hares

Lepus

What are the two special GALT tissues in rabbits associated w/ maturation of IgM B cells?

vermiform appendix (distal end of cecum)

sacculus rotundus (ileocecal junction)

What Ig do rabbits not have? What other animals do not have this Ig?

-IgD

-Rabbits, pigs, and hamster got GAME (IgG, IgA, IgM, and IgE)

Rabbits are the most preferred model for _____ antibody production

polyclonal

In humans and mice antibodies are created by _______ which is where a portion of the immunoglobulin gene is replaced with gene sequence from a nonfunctional psuedogene

gene conversion

In rabbits (chicken, sheep, and cattle) antibodies are created by ______ where single nucleotide changes are made in the immunoglobulin genes

somatic hypermutation

At what age do rabbits start making IgM B cells in GALT?

4-8wk

What intestinal bacteria is required for appendix follicle development and antibody diversification

Bacteroides fragilis and Bacillus subtilis

What are the 3 rabbit used for CV research for cholesterol induced artherosclerosis?

-Watanabe heritable hyperlipidemic (WHHL)

-St. Thomas Hospital Strain

-Kuorawa and Kusanagi hypercholesterolemic (KHC)

How to tell the difference between these 3 strains?

-Watanabe heritable hyperlipidemic (WHHL)

-St. Thomas Hospital Strain

-Kuorawa and Kusanagi hypercholesterolemic (KHC)

Watanabe heritable hyperlipidemic (WHHL)

-deficient LDL receptors, hypercholesterolemic

-Coronary artery atherosclerosis w/o affecting aorta

St. Thomas Hospital Strain

-normal LDL, but hypercholesterolemic

Kurosawa and Kusanagi hypercholesterolemic (KHC)

-Mutated LDL, w/ hypercholesterolemia

A GM rabbit exists for _______ dz (other heart dz)

Long QT interval

Another GM rabbit exists that expresses ______ in it's milk. This resulted in antigen production for _____, _____ and _____

-human recombinant proteins

-rotavirus vaccine, human factor VIII for haemophilia treatment, human growth hormone

Another GM rabbit produces _____ used for tracking cells important for tissue engineering and regen med studies

enhanced green fluorescent protein (EGFP)

The rabbit ocular irritant test (AKA____) has been replaced with what?

Draize test replaced with bovine corneal opacity test

The rabbit pyrogen test has been replaced with ______ and it uses the blood of ______

limulus amebocytes lysate test, horseshoe crabs

What is the thermoneutral zone for rabbits?

15-20c (59-68F)

What is the guide recommended temp for rabbits?

61-72F

Rabbits have a special exception in the AWA due to how cold they like it, what is it?

indoor housing need not be heated

What is the Dental formula of rabbits?

2 x [I 2/1 C 0/0 P 3/2 M 3/3] = 26 or 28

Absence of peg teeth is a recessive or dominant trait?

dominant

What kind of dentition do rabbits have?

Hypsodont (high crowned) & elodont (open rooted and grow continuously) on ALL teeth (incisors and cheek)

What other species have continuously growing incisors and cheek teeth?

Dipodomys (kangaroo rat), Microtus (vole), GuineaPig, Chinchilla

What kind of teeth do mice, rats, hamsters and gerbils have?

Myomorphs - elodont and hypsodont incisors, but anelodont and brachydont cheek teeth

Of the salivary glands listed below, which one do rabbits have that humans don't?

parotid, submaxillary, sublingual, zygomatic

zygomatic

Describe the musculature of the rabbit esophagus?

Three layers of striated muscle that extend down esophagus

Where are the only mucous glands located in a rabbit?

esophagus

The rabbit stomach does or does not empty?

never empty

What is a common finding in the stomach of a rabbit?

hair

The rabbit's common bile duct empties into the?

duodenum

Rabbits are a _____ fermentor?

mongastric hindgut fermentor

How does rabbit kits receive passive immunity?

GI tract is relatively impermeable to large molecules, kits therefore receive passive immunity via yolk sac prior to birth

The ____ regulates flow of chyme into the cecum

ileocecal valve

Peyer's patches in rabbits are found along the ___ near the _____

ileum, sacculus rotundus

Where is Sacculus rotundus?

second common site for foreign bodies

Lymphoid tissue at the ileocecal junction includes the sacculus rotundus and cecal tonsil

Rabbit's colon is divided proximal (haustra)/distal by the _______ which regulates production of hard vs. soft fecal pellets

fusus coli

Cecotropes (night feces) are soft pellets high in ____ and specific vitamins ____, ____, ____, and _____

-moisture

-B vitamins (niacin, riboflavin, pantothenate, cynanocobalamin)

Which vitamin B correspond to each? Niacin, Riboflavin, Pantothenate, Cobalamin

Niacin -B3, Riboflavin -B2, Pantothenate -B5, Cobalamin -B12

Rabbits on a ____ diet ingest more cecotropes

high fiber

In captivity cecotropes are eaten at _____, in the wild they are eaten during the _____

night, day

GI transit time for rabbit

4-5hr

____ in the diet leads to a proportional increase of ____ in the SI and serum.

calcium

A diet high in ____ can lead to renal disease

alfalfa hay

Diets low and high in Vit ___ can result in congenital hydrocephalus

A

Diets high in Vit ___ can result in calcification and mineralization of soft tissues

D

Vit ___ deficiency is associated with infertility, muscular dystrophy, fetal death, neonatal death, and colobomatous micropthalmos

E

Two main sources of energy in the rabbit

-sugars absorbed in small intestine

-volatile fatty acids produced during cecal fermentation

Butyrate produced in rabbit gut is likely due to ____spp.

bACTEROIDES

Cecum terminates in a thick walled blind sac, the __________

vermiform appendix

Rabbit intestine

A - Example of a Peyer's patch

B - sacculus rotundus

C - Cecal tonsil

D - Cecal appendix (vermiform appendix)

Rabbits are obligate ____ breathers

nasal

How to do rabbit CPR?

Because respiration is mostly by diaphragmatic movement, resuscitate by moving the head up and down rather than chest compressions. (BB: 30-45 times a minute)

In most other species _____ contributes more to respiratory effort

thoracic wall musculature

why is intubation hard in the rabbit?

laryngospasms, long & narrow pharynx, large tongue

lung lobes of rabbit

-left & right cranial, middle, and caudal lobes

-Right caudal subdivided into lateral and medial portion

______ increases with age (in regards to respiration)

lung volume

Have ____ like rats. Mice do not have this

BALT

What kind of valves is the right AV valve in rabbit heart?

Tricuspid valve (right AV valve) is bicuspid in rabbits

The SA and AV nodes in the rabbit are seperated from the annulus fibrosus by a _____

layer of fat

In rabbits the aortic nerve has only _____ unlike other species that have ___ and ___

-baroreceptors

-baroreceptors and chemoreceptors

The aortic nerve is a branch of the vagus nerve that ______

slowsl heart rate, dilates blood vessels, and reduces blood pressure

blood supply to the brain is via the ______

single internal carotid artery

Which two lab animal species has a unipapillate kidney? Why is the beneficial in research?

-Rabbits and Rats

-easy to cannulate

What mineral in the urine make it cloudy and red/brown?

Calcium Carbonate Monohydrate

Ammonium Magnesium Phosphate

Young rabbits may have ___ and that's normal

albumineria

Rabbit urine is very acidic or alkaline meaning it precipitates minerals

alkaline (8.2pH)

In rabbits glomeruli increase in # after birth, _____ are normal

ectopic glomeruli

In rabbits blood vessels perfusing the medulla remain open during many conditions that would normally cause vasoconstriction in other species. This means that the ____ will be perfused while the ____ is ischemic

medulla, cortex

Rabbits produce ___ mL/kg of urine a day

50-75mL/kg

_____ of rabbit water intake becomes urine

up to half

who urinates more does or bucks?

does

Rabbits are not sensitive to which diuretics?

high water intake 120ml/kg

Not sensitive to loop diuretics (furosemide)

When do the inguinal canals close in a rabbit?

they don't, they remain open

how many cervices does the rabbit have?

2

What lab animal species have two cervices?

Chinchilla Hamster Opposum Woodchuck Rabbit Rat

Who Only Has 2 Really Rad Cervices

The ____ or ___ is where the urethra enters the vagina

urogenital sinus or vestibulum

Rabbits have a _____ placenta, like humans

hemochorial

What does it mean to have a hemochorial placenta?

maternal blood flows into sinuses where transfer of nutrients occur for fetus (no barrier between maternal and fetal blood)

Both sexes have _____ which are scent glands that produce white to brown unpleasant smelling secretions

inguinal pouches lateral to genitalia

How to tell difference between a doe and a buck?

anogenital different, but even that is still pretty hard

Does male rabbits have nipples?

No

Rabbit kits are considered functionally ectotherms until ____ of age

7 day

What other species don't have IgD?

Rabbits, pigs, hamsters, g. pigs., cows, sheep, ducks, African Clawed frogs.

how many hours of glucose reserve do neonate rabbits have?

6 hours

How do rabbits stay warm?

-ear vasoconstriction, increased HR

Rabbits drink more water when consuming ___ feed

dry feed

What RBC morphology difference is normal in rabbits?

anisocytosis (variation in RBC size)

Predominant WBC in rabbit is the ___________

heterophil (their lymphocyte)

When does their thymus regress?

it doesn't

______ is the phenomenon where heterophils appear more like immature "band cells" - this is not a "left shift"

pelger-huet anomaly

______ are normal except nuclei of neutrophils/heterophils have reduced number of lobes

Pg/pg: "Pelgers" (heterozygotes)

_____ all leukocytes have round hyperchromatic nuclei, most of these animals die at birth

Pg/Pg: "Super-Pelgers" (homozygotes)

What other species can the pelger-huet anomaly be found in?

mice, dogs, cats, and horses

Rabbits prone to ___ and ____ elevation during muscle injury (restraint, cardiac puncture, etc)

AST & CK

Rabbits have ____ isoenzymes of ALP (Alkaline phosphatase) (most animals have ___).

-3

-2

Rabbits have three forms of alkaline phosphatase. Where do they come from?

One intestinal and two isoforms in the liver/kidney

1 multiple choice option

Carnivores, omnivores, or herbivores?

herbivores