1. BUCKTOOTHED
BUNNIES
A Study of a Fatal Feeding Flaw:
Rabbit Tooth Malocclusion
click here to
BEGIN SHOW

2. Back
Poppy
to family pedigree
“The Escape Artist”
Color Genetics
•Phenotype: agouti castor
•Genotype: Aa bb Dd enen
Teeth Genetics
•Poppy is homozygous dominant
Nibbling bread on a
chilly morning
Cuddling with her tiny kitten, Hazel, and recovering from kindling
for the recessive gene that causes
tooth malocclusion; she is
completely normal and all of her
litters are and will be unaffected.

3. Back
Harley
to family pedigree
“The Chubby Bunny”
Color Genetics
•Phenotype: broken black
•Genotype: aa Bb Dd Enen
Teeth Genetics
•Harley is homozygous dominant
Trying out her spotted
camo on a rare snowy
day
Enjoying leftover french fries and never sharing
for the recessive gene that causes
tooth malocclusion; she is
completely normal and all of her
litters are and will be unaffected.

4. Back
Hazel
to family pedigree
Color Genetics
•Phenotype: agouti castor
•Genotype: Aa bb Dd enen
Teeth Genetics
•Because Hazel never had a litter,
I will never know if she was a
heterozygous carrier or just a
homozygous dominant, normaltoothed rabbit.
Cuddling in the hay and trying to focus her
newly opened eyes
Gobbling up french fries and
looking like a walrus

5. Back
Midnight
to family pedigree
Color Genetics
•Phenotype: self color black
•Genotype:aa Bb Dd enen
Teeth Genetics
•I can never be really sure if
Adventuring in the
next box shortly after
opening her eyes
Scratching behind her ear while playing
Midnight was a carrier or not
because I never saw her at an old
enough age. She could possibly be
a carrier of the tooth malocclusion
causing gene or she could be a
completely unaffected normal
rabbit

6. Back
Apple
to family pedigree
Color Genetics
•Phenotype: broken blue
•Genotype: aa Bb dd Enen
Teeth Genetics
•Apple was a heterozygous carrier
Eating fresh lettuce,
her favorite food
Trying to reach the tasty grass
for tooth malocclusion; her kits can
either be expressers, carriers, or
normal, homozygous dominant.

7. Back
Sundance
to family pedigree
Color Genetics
•Phenotype: self color blue
•Genotype: aa Bb dd enen
Teeth Genetics
•Sundance could have possibly
Nibbling on alfalfa
pellets
Tasting grass for the first time
been a heterozygous carrier or an
unaffected homozygous dominant
rabbit.

8. Back
Rye
to family pedigree
“The True Cuddle Bunny”
Color Genetics
•Phenotype: self color blue
•Genotype: aa Bb dd enen
Snuggled up in a towel
Teeth Genetics
•Rye is an expresser of the
recessive tooth malocclusion
which means he is homozygous
recessive and suffers from
constantly growing crooked teeth
Only 10 weeks old and exploring his new home
Teeth before a checkup

9. Back
Milo
to family pedigree
Color Genetics
•Phenotype: broken black
•Genotype: aa Bb Dd Enen
Teeth Genetics
•Milo is unaffected by tooth
Hearing the lawn
mower for the first
time
Trying to get back in the nest box
malocclusion, but he has the
potential to be a heterozygous
carrier like his sister Apple.

10. Back
Blackberry
to family pedigree
Color Genetics
•Phenotype: black
•Genotype: aa BB Dd enen
Teeth Genetics
•Blackberry is unaffected by tooth
Tasting hay for the
first time
Exploring an old burrow, where he was actually born
malocclusion, but he has the
potential to be a heterozygous
carrier like his sister Apple.

11. Back
Thorn
to family pedigree
Color Genetics
•Phenotype: black
•Genotype: aa Bb Dd enen
Teeth Genetics
•Thorn is unaffected by tooth
Tasting grass for the
first time with his
sister
Adventuring around a new pen after being weaned
malocclusion, but he has the
potential to be a heterozygous
carrier like his sister Apple.

12. Back
Will
to family pedigree
“The Runaway”
Color Genetics
•Phenotype: self color lilac
•Genotype: aa bb dd enen
Teeth Genetics
•Will is heterozygous for the
Enjoying a tasty carrot
Contemplating the world outside the nest and trying the crawl
over
recessive gene that causes tooth
malocclusion; all of his offspring
have the potential to the carriers or
exhibitors or normal

13. Back
Sundance
to family pedigree
Color Genetics
•Phenotype: broken blue
•Genotype: aa Bb dd Enen
Teeth Genetics
•Cowboy is not an expresser of the
Gobbling up bread,
his favorite snack
Hopping around after being reintroduced to his brother, Butch
Cassidy
gene, but, because he has no sired
any litters, it is unknown if he is a
carrier or a normal, homozygous
dominant rabbit.

14. Butch Cassidy
Back
to family pedigree
Color Genetics
•Phenotype: broken lilac
•Genotype: aa bb dd Enen
B.C. shortly after I
first caught him.
Teeth Genetics
•Butch Cassidy was homozygous
recessive meaning he was affected.
His teeth seemed to be in worse
condition than Rye’s even though
he was younger.
Trying to stay cool in the shade
His teeth when I first
found him

15. The Current Dilemma
•
When she had finally given in to my constant begging, my mother never could have predicted the
incredible journey my little, fuzzy, feed-store bunny would take me on. Now, nearly 6 years later, I’m
one foot taller and millions more times experienced in the world of caring, breeding, and dentistry of
rabbits. Once a month, I go outside wearing gawky eye goggles, face the unpredictable Mississippi
weather, and proceed to trim my pet rabbit’s crooked teeth, formally known as tooth malocclusion. The
three years this monthly practice has been going on, I have wondered just what caused my rabbit’s
crooked teeth, and, after several accidental litters, I came across another rabbit with malocclusion, and
began to wonder just what could be causing this, and so my observational experiment began.
Poppy, my very first rabbit and the mother of my first litter
Rye, my first buck and the original rabbit with
tooth malocclusion

16. Effects of Tooth Malocclusion
•With his crooked teeth, Rye has a hard time doing normal rabbit things like grooming, drinking, or even
eating. Tangles and mats form in his fur because grooming is not possible, and whenever his teeth are
freshly trimmed, he vigorously washes. Because of the difficulty of chewing, Rye always chooses soft,
high calorie food, and methodically grinds his treats with his back molars. Drinking out of water dishes
offers a new challenge, and Rye always manages to wet his entire muzzle in the process.
•To trim Rye’s quick-growing teeth, I wrap him up in a comfortable towel, wedge open his mouth with
my fingers, and begin to trim down his teeth. Even though I put him through this seeming torture every
month, Rye has remained the friendliest rabbit in the pen, and is always eager to be cuddled or trimmed.
Before his tooth checkup
After his tooth checkup

17. Using the Scientific Method
•
Before beginning the experiment, I needed to set up my information according to the scientific process
which requires research to be conducted, a question to be asked, a hypothesis to be formed, and a
conclusion to be drawn.
•
•
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The Research is depicted on the following slides
•
The Conclusion will be formed after further observation study of the hypothesis
The Question: What is causing malocclusion in my rabbit’s teeth?
The Hypothesis: If a rabbit inherits the homozygous recessive gene from its heterozygous carrier
parents, then it will be affected by tooth malocclusion.

18. Research Step 1
Studying genetics and other influences
•
TEETH- For years, rabbits have been used by researchers and geneticists because of their ease of
•
COLOR- Rabbit fur coloring is controlled by 10 or so recognized allele groups. In my study,
care, short procreation, and startling chromosomal similarities to humans. As different breeds
developed and led to the constantly growing pet rabbit trend, inbreeding and other genetic
shortcomings spawned tooth malocclusion, causing people to wonder just how their “peter
cottontail” became a tusky, grumpy tasmanian devil. Researchers began to the study the gene and
have recently come up with several conflicting reasons, so I decided to make a hypothesis and test
it.
however, I decided to only focus on the 4 following allele sets.
Gene Descriptions Dominant
Allele
Recessive Allele
Agouti/Self Color
A
a
Black/Brown
B
b
Dense/Dilute
D
d
Broken/Self Colored
En
en

19. Research Step 2
Organizing my own information
•
Using my education from ninth grade biology and the internet, I began to study my own notes and tried
to decipher genetic or environmental connection in the inheritance of tooth malocclusion. I had
personally raised one of the other rabbits who was an expresser of the gene, so I could rule out
nutritional deficiencies as being a cause. As I began to look for other answers, I also noted that both
expressers I had experienced were male, making me ponder the possibility of a sex linked trait, but then,
it hit me! Tooth malocclusion followed the exact pattern that any recessive gene would follow in a
family tree.
•
Rye, my original rabbit with tooth malocclusion, would be homozygous recessive; his kits, Apple and
Will, would be heterozygous carriers. When they escaped and I found their accidental litter four weeks
later, I caught two of the kits. One was completely unaffected, but the other was homozygous recessive
for tooth malocclusion, confirming his sire and dam as carriers of the sometimes deadly gene. The
alleles included in my recessive gene hypothesis for tooth malocclusion are pictured below.
Phenotype
Genotype Normal?
homozygous
dominant
TT
normal
heterozygous
Tt
carrier
homozygous recessive tt
expresser

20. Key
male
female
untested
potential carrier
Rye
Poppy
Hazel
normal
expresser
The Family Tree
known carrier
Midnight
CLICK ON ANY RABBIT
TO GO TO A
PERSONALIZED PAGE
OF INFORMATION
Will
Butch Cassidy
Harley
Apple
Cowboy
Sundance
Blackberry
Thorn
Milo

21. Hypothesis and Explanation
•
The before stated hypothesis is supported by the pattern of inheritance show in the family tree. By
skipping one generation and revealing itself in the next, the gene for tooth malocclusion is very
similar Mendel’s famous purple and white peas. These recessive genes, as Mendel dubbed them,
can be carried for generations without appearing.
•
In my personal experiment, the recessive genes appeared after only 1 generation. Rye, a
homozygous recessive, passed on one recessive allele to his offspring making them heterozygous
carriers. When the heterozygous carriers bred, another homozygous recessive rabbit, Butch
Cassidy, reveled itself.

22. Conclusion
•
As I went along in my researching for other causes, I became more and more certain that tooth
malocclusion in rabbits in caused by a recessive gene. Several research groups have done studies
supporting this hypothesis, and controlled experiments have shown that nutritional and
environmental conditions have little or no affect on tooth malocclusion. Different breeds are more
or less susceptible to this fatal disease, but smaller breeds such as Mini Rexes are at a much higher
risk.
•
Learning about rabbit genetics opened my eyes to the detailed genes that combine to create a
small, furry creature. With 42 chromosomes, rabbits can teach us a great deal about our own
genetic history and possibly explain our dental malocclusion too.

23. Sources
•
During my research, I used the following sites and books to learn more about rabbit genetics and
tooth malocclusion:
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http://jorthod.maneyjournals.org/content/26/3/195.full
Rabbit Production by Steven D. Lukefahr
http://www.ufaw.org.uk/DENTALMALOCCLUSIONNETHERLANDDWARF.php
http://www.bio.miami.edu/hare/dental.html
http://www.doubledeckerrabbitry.com/rabbit_color_genetics
http://www.debmark.com/rabbits/genetics.htm
http://rabbitgenetics.weebly.com/index.html

24. Thanks for Watching!