Transcript Document

81 Webb Street, Salem, MA 01970
(978) 744 – 8020
Kathleen K. Ternes DVM, DABVP Elaine M. Bird, DVM Holly E. Willard, DVM
Kidney Failure (Chronic Renal Failure)
Adapted from The Pet Health Library by Wendy C. Brooks, DVM, Dipl. ABVP
Educational Director, Veterinary Partner.com
What You Should Know
If My Pet is Still Making Plenty of Urine, How Can There Be Kidney Failure?
In chronic renal failure, or CRF, urine is usually produced in excessive quantities.
What the kidneys are failing to do is conserve water (they are failing to make
concentrated urine). The body produces numerous toxins on a moment by moment
basis. These toxins circulate to the kidneys where, dissolved in water, they are filtered
out and urinated away. An efficient kidney can make a highly concentrated urine so
that a large amount of toxin can be excreted in a relatively small amount of water.
When the kidneys fail over a long time period, they lose their ability to concentrate
urine and more water is required to excrete the same amount of toxin. Your cat will
begin to drink more and more to provide failing kidneys with enough water and
ultimately, they will be unable to drink enough. Toxin levels will then begin to rise.
Weight loss, listlessness, nausea, constipation and poor appetite may become
noticeable. It is common for animals, especially cats, to have a long history of excessive
water consumption when they finally come to the veterinarians office with one of the
latter complaints.
What Is My Veterinarian Reading on the Labwork?
If you wish to understand your pet’s status with regards to kidney failure, it is important
to understand some of the parameters being monitored.
Urine Specific Gravity -
Blood Urea Nitrogen (BUN) -
This is a measure of how concentrated
a urine sample is. Water has a specific
gravity of 1.000. A dilute urine sample
has a specific gravity of less than 1.040.
A concentrated urine sample would
have a specific gravity over 1.040.
This is a protein metabolite excreted by
the kidney (it is one of the toxins we are
concerned about). In a normal animal,
the BUN is 12 – 30. In renal failure,
BUN may range from 40 – 90 when
diagnosed at an early stage, or over 150 200 when diagnosed at an advanced stage.
Creatinine - This is another protein
Phosphorus – The calcium/phosphorus
Metabolite (though this one is less
dependent on dietary protein intake
than BUN). A normal creatinine is
less than 2.3. BUN and creatinine
Will be monitored (as well as several
Other parameters) over time and in
response to different treatments.
balance becomes deranged in kidney failure
due to hormone changes that ensue as well
as the inability of the failing kidney to
excrete phosphorus. If calcium and phosphorus levels become too high, the soft
tissues of the animals’ body will develop
mineralized deposits which are
inflammatory and uncomfortable. The
bones will weaken as well. Medications
and special diets can be used to keep
phosphorus levels down.
Potassium- The failing kidney is
Unable to conserve potassium
efficiently and supplementation may
be needed. Signs of hypokalemia (the
Scientific term for low blood potassium)
Includes weakness, especially drooping
of the head and neck and poor appetite.
Blood Pressure- Blood pressure
is checked in the exam room with a
Doppler monitor and it is important
to monitor in kidney patients as there
is a tendency for hypertension to
develop in kidney failure. Special
medications may be needed to
manage this problem should it arise.
Untreated high blood pressure can
cause retinal damage/detachment
resulting in blindness.
Packed Cell Volume/HematocritThis is a measure of the percentage of
blood made up by red blood cells. The
hormone that stimulates the production of
red blood cells is made by the kidney. The
failing kidney does not make this hormone
in normal amounts and anemia can result.
Anemia is often worsened by the extra fluid
administrations needed to manage the
kidney toxins. Sometimes, a blood
transfusion is needed or, more commonly,
the owner of the pet can learn how to give
hormone injections to boost the red blood
cell count.
What Are The Treatment Options?
What one does to address this problem depends on its stage at the time of diagnosis.
More advanced cases will require hospitalization for a cycle of diuresis where fluids are
delivered intravenously for 48 – 72 hours and the above parameters are rechecked.
The goal is to stabilize the patient at a toxin level where a good quality of life can be
experienced.
Milder cases can be managed with fluid administration under the skin (subcutaneous
fluids) at home. Some cats will tolerate this procedure well.
What Sort of Treatments Might My Cat Require At Home?
Special Diet-
Most prescription diet
companies produce a diet with restricted
protein (so as to generate less BUN),
restricted phosphorus, and with other
important qualities to promote metabolic
health in patients with compromised
kidneys. Hills Prescription Diet K/D
canned and dry food, Purina Veterinary
Diets NF canned food and Royal Canin
Renal LP Modified canned food are all
types of diets we can offer to kidney
patients.
Epogen (Erythropoeitin)-
The
hormone that the kidneys have failed to
produce can be replaced by this
manufactured injectable hormone. It
stimulates the production of red blood
cells. This can be done at home 2 – 3
times a week.
Norvasc (Amlodipine)-
This
blood pressure medication is of the
calcium channel blocker type. It is
commonly used in hypertensive cats with
kidney issues. Benazepril (Lotensin) is
another medication that is used alone or
in conjunction with Amlodipine to
decrease vasotension to the renal artery
and increase blood flow to the kidney.
This results in more efficient kidney
filtration.
Potassipowder/PotassitabsThese potassium supplements are
available in powder or tablet form. If a
patient is not maintaining a normal
potassium level, these may be
prescribed.
Fluids Under the Skin-
Giving
subcutaneous fluids is a technique
important to learn, as many cats in
kidney failure require this treatment at
some point in their lives. If this
process is recommended for your cat,
you will receive lessons on how this
technique is preformed. Usually,
once your cat starts fluid treatment, it
will continue to be on some form of it
for the rest of its life. This could be
once a day, once every other day or a
few times a week. The frequency
depends on how your cat responds to
treatment. This can be determined by
rechecking blood values. Potassium
and B vitamins may also be added to
the fluids for extra benefits if needed.
Alucap (Phosphate Binders)Alucap is an antacid caplet used for
stomach upset. It also binds
phosphates in the diet when it is given
with food. This reduces the
phosphorus intake from the GI tract
and helps normalize the blood
phosphorus level.
Appetite Stimulants-
Many
kidney failure cats have a decreased
appetite. Periactin (Cyproheptadine)
and Remeron (Mirtazapine) are
appetite stimulants that may be used
on and off during treatment to help
maintain a healthy appetite.
Pepcid-
This is a human drug that
comes in tablet form. It is safe to use
in cats. It helps to ease nausea and
prevent stomach ulcers that can
occur with kidney failure.
Antibiotics-
Kidney failure can make
your cat more susceptible to kidney and
urinary tract infections. Antibiotics may
be used to help prevent or treat an
already existing infection.
Follow-up Labwork After Initial Diagnosis:
 Periodic bloodwork to monitor renal values.
 Packed Cell Volume/Total Protein to monitor anemia - more frequently if your cat
is being treated for anemia.
 Electrolytes to monitor sodium, potassium and chloride levels, especially if your cat
is on a potassium supplement.
 Urinalysis to monitor urine specific gravity and periodic urine cultures to rule out
urinary tract infections (to which kidney failure cats are very susceptible and are
very dangerous to them).
 Blood pressure, routinely, to monitor for hypertension - more often if your cat is
being treated with medication for hypertension.
Kidney failure is a complicated disease with many
facets. Please do not hesitate to call The Feline
Hospital should you have any questions or problems
at home.
You Are Not Alone: Further Resources
Chronic renal failure is a common disease and there are many pet owners just like
you, all sharing thoughts, tips and information over the internet. If you are
interested in exploring these resources, here is what is available:
 http://www.felinecrf.com/ is a vast source of information compiled by the
owner of Avatar, a cat who ultimately succumbed to his kidney failure.
 An online mailing list for owners of cats with kidney failure is available at
http://pets.groups.yahoo.com/group/Feline-CRF-Support/. Sign up to
subscribe.
 http://www.holisticat.com/crf.html is another resource including candid
experiences with CRF treatments.