Hi all, here’s a very good article on bunny diet, from a very rabbit-savy vet. It’s long, but I hope you don’t mind.
Diet – The House Rabbit Society
Rabbit GI Physiology and Nutrition
Susan A. Brown, D.V.M
Midwest Bird and Exotic Animal Hospital
Westchester, IL 60154
Rabbits are strict herbivores. Their relatively small body size makes
it difficult to store large volumes of coarse fiber as might be done
in the cow or horse. The gastrointestinal tract (GIT) attempts to
eliminate fiber as quickly as possible. Large fiber particles
stimulate motility of the GIT. The rabbit then utilizes the non-fiber
portion of the food to produce the nutrients that are needed for
life, some of which are absorbed directly from the GIT and some of
which are reingested in the form of cecotropes. This particular
system allows for a large volume of food intake, with a rapid
digestive transit time thus increasing the total amount of energy
stored and minimizing the need to store fiber.
Ingested food first enters the stomach, where the pH is approximately
1-2 creating very acidic environment. Preweaning rabbits have a
stomach pH much closer to neutral (5-6.5) which allows bacterial
flora to be initiated into the GIT. After weaning the pH drops
dramatically. It is not known what the pH of the stomach is in all
states of disease or anorexia and even in health the pH may not be
constant. However, published research tends to support that the
stomach environment is normally quite acidic.
Ingesta in the stomach is essentially sterilized, massaged a bit and
broken down into smaller particles. It then moves into and through
the small intestine where nutrients are extracted, and more water is
added resulting in a fluid content. It may take several days for the
stomach to completely empty, so fasting a rabbit to empty its GIT for
diagnostic testing as in the case of radiography to detect a gastric
foreign body, generally does not work. In addition, the fasting
itself will slow down gut motility because the fiber which “drives”
the system is not being taken in. It is not recommended to fast a
rabbit prior to a surgical procedure. Rabbits do not have ability to
vomit.
At the end of the small intestine is the ileocecocolonic junction.
The cecum is a large blind sac in which resides a specific population
of bacteria that break down digestible fiber whereas the indigestible
fiber drives the GI tract and keeps things moving. Through bacterial
fermentation proteins, fatty acids and certain vitamins are produced.
Some of these items are directly absorbed thorough the wall of the
cecum, but most are returned to the rabbit when it eats the
cecotropes which are formed nutrient rich “feces” that come directly
from the cecum. Hard waste feces (what is found on the floor of the
cage) which have a high fiber content, are produced for approximately
the first four hours after the rabbit eats its food and the
cecotropes are produced during the next four hours (therefore not
only at night). The cecotropes are ingested directly from the anus,
have a mucous coating, are soft, moist have a stronger odor and are
brighter green color that the dry waste feces. This mucous coating
helps to protect the microflora through the acid pH of the stomach.
The dominant bacteria in the cecum of the healthy adult rabbit is
Bacteriodes with small amounts of Clostridium sp. and E. coli. Note
that Lactobacillus species are not common or normal inhabitants of
the adult rabbit GIT, therefore, in my opinion it makes no sense to
feed products that contain Lactobacillus to our pets. In addition,
unprotected live bacterial products fed to a rabbit will be destroyed
in the very acid pH of the stomach. If we truly want to repopulate to
GIT with healthy bacteria, we should be using the species that are
normally present in health. Some practitioners have advocated giving
the fresh cecotropes of healthy rabbits to ill patients. This is
probably not a bad idea, but the problem is that it may be difficult
to collect the cecotropes due to the fact that rabbits eat them
directly and the healthy individual doesn’t usually “drop” them in
the cage unless they have a collar placed on them, which is
stressful. If cecotropes are used, they must be retained in their
“whole” form to protect their mucous coating (i.e. not ground up).
Probably only 2 or 3 cecotropes are needed.
When the liquid small intestinal contents get to the area of the
junction of the large intestine and cecum it enters sac-like areas in
the wall of the cecum and colon called haustra which move food along
by muscular contractions. When the liquid small intestinal contents
reach this junction the long fibers are separated from the digestible
portion of the food and moved into the center of the colon where they
become the hard, dry waste feces and are passed out of the body. The
digestible portion of the intestinal contents are moved into the
cecum to undergo fermentation. The haustra move the liquid ingesta
back and forth in the cecum and in the colon continually separating
fiber from digestible particles. In fact, in the colon, water is
actually excreted into the lumen to aid in the separation of fiber
and non-fiber portions. The large fibers are moved towards the center
of the lumen and the digestible particles accumulate along the wall
in the haustra of the large intestine. These digestible particles are
then are moved in a retrograde fashion back into the cecum.
There is a constant flux back and forth in the cecum and upper third
of the colon to mix and separate food particles. Because it is so
important to have a liquid consistency to the ingesta in this area to
allow sorting of materials, it could be detrimental to administer
such materials as psyillium (Metamucil) to rabbits, because these
products tend to absorb moisture to create bulk and the end result
may actually be constipation.
So back to diet of the HOUSE RABBIT….I want to stress that we are
speaking here of the nonproduction, nonreproductive house pet
specifically. We recommend feeding the house rabbit a diet that is
high in fiber and relatively low in calories (especially fats and
starches). Unfortunately, over the years, we have seen pelleted diets
become a problem in the maintenance of the house rabbit. Pelleted
diets were originally formulated for the rapid growth and ease of
care of the meat or fur production rabbit, and for laboratory
rabbits. Most of these rabbits were not meant to live out their full
life span. The pellets perform an excellent function in these
situations, as they produce rapid growth, good weight gain, are
efficient, economical and easy to feed. The problem comes when we
have a house rabbit that is usually neutered, is expected to live out
its full life potential, and unfortunately may not get all the
exercise it needs. Pelleted diets are typically made up of chopped,
compressed alfalfa hay, various grains and other added nutrients.
Grains can be quite high in calories (starches and fats) and usually
lower in fiber than just hay. The alfalfa hay in pellets is chopped
and compressed and heated and may lose some of its fiber quality.
The problems that we and other practitioners have seen over the years
when pets are fed an unlimited primary pelleted diet are obesity,
chronic soft stools (mixed with normal stools) and periodic bouts of
anorexia (commonly known as “hairballs”, but what I feel is more
likely a GIT motility problem.) We have also seen less frequently,
calcification of blood vessels (some pellets are quite high in
calcium), and bladder and kidney stones. I am not going to say that
all of these problems are entirely caused by the diet, but my
observation is that diet plays a very big role. If we correct the
diet, then we can attend to other factors that may be still be
present. Some manufacturers of pellets have been sensitive to the
needs of the house rabbit and are producing higher fiber and lower
calorie pellets. Unfortunately other manufacturers have gone the
opposite direction and have decided to add all kinds of dangerous
things to the pellet mix such as seeds, nuts and additional grains in
the name of marketing without sufficient knowledge of what the
consequences can be. Regardless, I think that those of us who deal
with house rabbits should not depend on pellets as the total food
source for our house rabbits.
The diet that we recommend for the ADULT, NONREPRODUCTIVE HOUSE
RABBIT (and we did not “originate” this, there are plenty of
practitioners around who have done this for years) is no more than
1/8 cup/4 lbs. of body weight of a high fiber maintenance type pellet
(18% or higher fiber) per day. (Some adult animals are given no
pellets at all if they have trouble losing weight or have chronic GIT
problems). In young growing animals the pellets may be given free
choice until they are about 6-8 months of age, then cut back to the
maintenance amount. Fresh hay should be offered FREE CHOICE
throughout the pet’s life. THIS IS THE MOST IMPORTANT PART OF THIS
DIET AND MUST BE AVAILABLE ALL THE TIME. Young bunnies should be
exposed to hay as soon as they can eat on their own. Mixed grass hay
or timothy hay is the preferred type because it is lower in calcium
and calories than alfalfa hay. Try contacting a horse barn or feed
store for your source. If you have three or more bunnies, just buy a
bale and store it in a cool dry place, because you will use it up
quickly! If you cannot get the grass hay, then use alfalfa, but be
cautioned that it is much higher in calories, and calcium. I prefer
that rabbits on 100% alfalfa hay not get pellets at all, because it
is somewhat redundant.
We also like for our bunnies to get greens and lots of them. We pick
the tough fibrous greens which are rich in a variety of nutrients. We
suggest feeding a minimum of 3 types daily in a total MINIMUM total
amount (of all types of greens together) of 1 heaping cup/4 lbs. body
weight. Note, that this is a minimum, because as the bunny adjusts to
it more can be fed. By feeding several types of greens daily, you
will provide a variety of nutrients as well as not creating a finicky
rabbit. Some of the excellent greens are kale, collards, beet tops,
carrot tops, parsley, dandelion greens, mustard greens, romaine
lettuce, broccoli leaves, Brussels sprouts, outer cabbage leaves,
raspberry leaves, peppermint leaves, escarole, endive, raddichio,
wheat grass, alfalfa sprouts, etc. Don’t feed light colored greens
(i.e. iceberg and bibb lettuce) or the mixed gourmet greens in a bag
as the only source. Other vegetables such as carrots, pea pods (not
the peas), green pepper, squash, can be fed. Stay away from starchy
foods such as legumes (beans and peas) and corn and other grains.
Fruit can also be fed with some restrictions. Stay with high fiber
fruits such as apples, pears, peaches, papaya, pineapple, and
strawberries, but stay away from sugary fruits such as bananas and
grapes. The fruit and vegetables we feed in the amounts of 1 -2
Tablespoon/4 lbs. body weight daily.
Do not feed grains such as oats, corn, wheat, crackers, Cheerios,
bread, crackers, pasta, etc. There is research to suggest that high
starch and low fiber diets may be two of the contributing factors to
often fatal cases of enterotoxemia. Enterotoxemia can be caused by
changes in cecal pH resulting in the overgrowth of certain bacteria
that produce dangerous iota toxins that when absorbed into the body
ultimately lead to death. I know the bunnies love this stuff and in
small amounts, and in adult rabbits it wouldn’t normally be a
problem, but often clients overdo and it may result in serious GIT
disease. We have seen rabbits that continued to have periodic soft
stools when all else was corrected about the diet, yet they still got
two crackers a day. When the crackers were removed, the stools
returned to normal.
For obese rabbits and those that have that chronic intermittent soft
stool mixed with normal stool, I take them entirely off of pellets
and feed only hay free choice for two weeks. Then I will add back in
some greens and then eventually try them on small amounts of pellets.
Obviously, you must make sure that the rabbit is eating hay before
embarking on this diet, or else it might starve. In addition the
bunny should have a thorough physical examination and diagnostic
tests, if appropriate, to rule out other disorders prior to starting
this diet. Removing all the pellets from the diet sounds drastic, but
it works well and the bunnies seem happier and more lively as the GIT
starts to work more normally again. I have had clients tell me about
complete personality changes (for the better usually) when we got the
weight off their pets or got rid of those soft stools that stick all
over the fur and make the rabbits and the owner miserable. Some
rabbits can never go back on pellets again, because the soft stools
may return or the weight goes back up. In addition, rabbits that have
renal or bladder stones will also be taken off pellets and alfalfa
hay for life to help reduce the calcium intake.
I feel that it is a mistake to “fast” rabbits for long periods each
day to reduce weight, as in the cases where rabbits may be given
pellets for only a certain amount of time a day. This leaves the pet
with nothing to do physiologically and mentally for long hours. In an
animal that was designed to eat large amounts of food frequently it
can be frustrating and stressful. In addition, I fear that it may
lead to a sluggish GIT due to lack of stimulation. These pets will
frequently start eating paper, wood and anything else they can get
their teeth on the stave off their cravings. How often have you seen
the pet that has stopped eating pellets, but eats all the newspaper
in the cage? These pets are usually not on unlimited (or usually any)
hay or greens and are craving fiber.
Practitioners worry that if we take the rabbits off the pellets, they
will not get all the nutrients, vitamins and minerals that they are
supposed to get. Remember, that the rabbit manufactures its own rich
supply of nutrients in the cecum in the form of the cecotropes,
because they were designed to be able to live off of a “poor” quality
diet in the wild. I have not yet able to detect nutritional
deficiencies on the diet we recommend and we have been recommending
it for at least 5 years. In addition I rarely see a case of
“hairball” on this diet. The cases of “hairball” that we see in the
practice are on a primary pellet diet with little or no hay or
greens. In my opinion, “hairballs” are an accumulation of ingesta an
hair that takes place over time due to low GIT motility, until it
reaches such a size that the rabbit stops eating. Treatment for this
problem is aimed primarily at correcting the underlying dietary
problems.
As far as other supplements. … There has been a lot of talk about
using enzymes, and bacteria, etc. I think that these things do no
harm, but are not necessary when the pet in put on a more “natural”
diet. I used to recommend some of these items myself, no longer
because I do not see the need to do so. I would like to see those
people who are using these products first make the diet changes as
suggested in this article and then be able to quantitatively document
that the addition of the other “supplements” made any difference in
the appearance or behavior of their pet. I certainly have been proven
wrong before, but I feel more scientific research needs to be done on
these various supplements to really determine if they are making a
difference.
I will stress that there are a wide variety of diseases that can
affect the rabbit and certainly they are not all going to be cured by
a diet change. There must be a thorough physical examination and
appropriate diagnostic testing performed prior to any drastic life
style change for the pet.
Let’s feed our pets the way they were designed to eat..lots of food
with high fiber content. When they can “fill up” on hay and greens,
many of them lose interest in chewing up paper and furniture
(although they never lose interest in electrical cords). Let them out
to exercise also, to get the weight off, keep it off and keep all the
body’s systems in good working order.
Store
.
, and those are definately the first thing he goes for in the morning when he shoves my hand out of the way after I put it in his bowl. It does have timothy hay listed as an ingredient, but alfalfa is first so I’m guessing that means that ones the primary ingredient. I’m embarassed yet again, because I should know better, but I started feeding my guinea pigs the guinea pig version of this food becuase they wern’t eating their pellets and I thought the ‘treats’ in it would entice them, so when I got Boo I just got the same brand for him, only he empties his bowl usually, where the piggies never did. 
