Urine Scald: A Symptom of a Greater Problem
by Dana Krempels, Ph.D.
University of Miami Biology Department
House Rabbit Society of Miami
A rabbit suffering from urinary tract problems may experience loss of fur in the genital
region and hindquarters. The baldness and red, irritated skin are caused by "urine scald,"
and it can happen to any bunny whose urine soaks into the fur around her vent and is in
constant contact with her delicate skin.
There are many possible reasons for a rabbit to dribble urine and/or
sit in urine, and the only way to know for sure is have your rabbit
completely examined by a veterinarian
experienced in rabbit medicine.
Some possible causes of urinary incontinence (and hence, urine scald) to consider are the
All rabbits normally excrete excess calcium and oxalate salts via the
urinary tract, and the residue of normal urine will often appear
"chalky." However, when excessive amounts of calcium/oxalate salts
precipitate in the urinary tract, they sometimes manifest as a thick,
curry-colored "sludge" that sometimes has a consistency as thick as
toothpaste. This can be very painful in the bladder and when it is
passed, and sludge buildup can cause urine leakage and incontinence.
Bladder stone (urolith)
Although some vets suggest reducing dietary intake of calcium to help
control this problem, we have not found any correlation between dietary
intake of calcium and severity of sludge. Rather, this seems to be a
metabolic problem suffered by a few individual rabbits, and may be an
endocrine problem, rather than a dietary one.
Treatment for bladder sludge may include bladder flushes (in severe
cases), or simply helping the bunny flush the bladder by administering
subcutaneous fluids and a small dose of diazepam (Valium) to help relax the
bladder sphincters. Your vet will know best how to treat your rabbit's
particular problem, if this is what it turns out to be.
Diagnosed via radiography, a bladder stone is a mass of
calcium and/or oxalate salts that has precipitated into a solid mass.
Like sludge, a urolith can cause urinary incontinence and dribbling.
Unfortunately, the only viable treatment at this time is surgical removal.
Urinary tract infection (UTI)
Bacteria can infect the urinary tract (kidneys and/or bladder), just as
they can many other organ systems. The best way to diagnose this
particular ailment is via cystocentesis: inserting a sterile needle
into the bladder and extracting a sterile sample into a syringe. This
is then sent to a laboratory for Culture and
Sensitivity Testing. This will reveal (1) what species of
bacteria is causing the infection and (2) which rabbit-save
antibiotics (with good urinary tract penetration) will kill them.
Arthritis of the spine or pelvis
Unfortunately, urinary tract infections are sometimes caused by
"fastidious anaerobes": bacteria that die upon the slightest exposure
to oxygen. If this is the case, then the culture and sensitivity test
will come back negative. However, your vet may be able to determine
if a UTI is likely by examining the urine under the microscope for
signs of blood and white blood cells in the urine. If there is a good
chance that your bunny has a UTI, even if the culture comes back
negative, your vet might wish to put her on a course of antibiotics
such as chloramphenicol, which is effective against many anaerobes and
also concentrates well in the urinary tract. Your vet is the best
person to advise you on the proper course of action in case of a UTI.
Arthritis of the spine or pelvis can result in the rabbit's inability to posture
correctly for urination. This can cause urine to collect in the
fur and soak into it, causing urine scald.
Rear limb/pelvic paresis
Arthritis can be diagnosed via radiography, and can often be helped
tremendously with non-steroidal anti-inflammatory drugs such as
carprofen (Rimadyl) or flunixin meglumine (Banamine).
Paresis is defined as a weakness without total loss of movement in a
particular area of the body. This problem is not uncommon in older
rabbits, and some even lose the use of their hind legs. The
problem may be caused by arthritis, disc degeneration or other
skeletal problems. Some vets suspect that a central nervous
system/renal system parasite known as
Encephalitozoon cuniculi might be responsible for this condition,
but there is still no conclusive clinical evidence to support this
Some people have reported excellent improvement of paresis with acupuncture
and massage, whereas others have seen improvement with short-term use of
anti-inflammatory drugs (e.g. corticosteroids, which should not be used
long term). This also helps with urinary tract continence.
E. cuniculi is being experimentally treated with any one of several
related drugs (albendazole, fenbendazole, oxibendazole, etc.), and although
some individuals have reported improvement in the condition after using
these drugs, there
are still no studies to show conclusively that such treatments are
Unspayed female rabbits have a very high risk of developing uterine
cancer, and a large tumor can sometimes interfere with normal
urination. All female rabbits should be spayed for their health and
Incontinence due to hormone imbalance
Our vets have noted that removal of the cancerous uterus (via spay
operation) usually solves the problem, and they have not noted a high
degree of metastasis (spreading) in this type of cancer, once the
uterus is removed. Spaying is the best treatment option for this
Because rabbit spaying is a relatively recent notion, data are not yet
complete on the long-term effects of early spay. In at least one
case, incontinence believed to have been due to hormonal imbalance was
successfully treated with DES, a synthetic estrogen.
While your veterinarian is performing diagnostic tests to determine the
reason for your rabbit's urine scald, your job will be to keep her
comfortable, clean and dry. You can do this by giving her regular "butt baths" when
she is soiled (follow the link for instructions), and by administering
analgesia (e.g., Banamine) as per your veterinarian's instructions.
The Color of Urine
Healthy rabbits excrete excess calcium salts via the renal system, and
this can give the urine a chalky or opaque appearance. The urine will
often dry to a white, chalky residue. Unless the residue is thick,
pasty, and the color of mustard powder, this is normal, and should not
be considered "sludge."
Normal rabbit urine is usually pale yellow in color, but upon exposure
to the atmosphere, compounds in the urine may oxidize to darker yellow,
orange, red, or even dark brown. This isn't unusual, and--by itself--is not
necessarily a sign of a health problem. Blood in the urine, unless it
is from a hemorraghing uterus or very serious problem, is usually not
readily visible to the naked eye. Test strips are available at most
pharmacies that will tell you whether there is blood in the urine or not,
but your vet is the best judge of whether your bunny's urine is
Urine that is very dark immediately when it emerges may indicate that
the bunny is dehydrated, and should receive more water, either by mouth
or--in more serious cases--via administration of subcutaneous Lactated
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