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Kidney Disease in Cats and Dogs
by Dr. Jean Hofve
Kidney disease is a frequent problem in older cats and dogs. Kidney failure can
develop in young animals, but it is far more common in pets over age 10. It is
the leading cause of death in older cats.
In the Pet Food Recall of 2007, melamine contamination of pet food caused tens
of thousands of cats and dogs to develop Acute Renal Failure (ARF). Many of the
pets who got sick but recovered likely suffered some kidney impairment, and may
ultimately develop Chronic Renal Failure (CRF). In that case, age makes no
difference; animals of all ages were affected.
The kidney filter out and excrete toxins from the body through the urine.
Healthy kidneys conserve water and concentrate toxins into a smaller amount of
liquid to be urinated away. The kidneys have a very large reserve capacity, and
symptoms of failure are not seen until approximately 75% of kidney tissue is
nonfunctional. When the kidneys are damaged, they become less able to
concentrate the urine. Because they’re losing water in the urine, they need to
drink more—but because they’re drinking more, they urinate more. So the first
and most noticeable symptom is usually an increase in water consumption and
urination ("drink-a-lot, pee-a-lot syndrome").
As the kidneys lose function, other signs of CRF may occur, such as weight loss,
nausea, constipation, low energy, fatigue, and poor appetite. A blood test and
urinalysis should be done if you notice these symptoms, as there are many
conditions that can cause them. A blood test and urinalysis are necessary to
accurately diagnose CRF.
The measurement of urine concentration is called Urine Specific Gravity (USG).
If the USG is low (less than 1.035 in cats, and 1.030 in dogs) and there are
abnormal levels of two other compounds, then kidney function is reduced. The
first, BUN (blood urea nitrogen), may be high if the animal is dehydrated, or
eats a very high protein diet. However, as long as the kidneys are able to
concentrate the urine, small elevations in BUN are usually not a cause for
alarm. The second is a protein called creatinine. Creatinine is a more sensitive
measurement of kidney function; an increase in creatinine usually means that the
kidneys are having problems. In advanced disease, an increase in phosphorus is
also seen, and indicates that 85% of kidney tissue is damaged.
Treating CRF
No conventional or alternative medical treatment can reverse CRF, since the
disease involves the death of kidney cells and replacement by scar tissue. The
rate of progression in any individual pet may be slowed, but not stopped, by
various treatments. When the process is advanced, the kidneys become scarred,
small, and lumpy, and the amount of functional tissue is greatly decreased. The
most significant problems caused by the loss of function are build-up of blood
toxins, and anemia. These can cause weight loss, lethargy, vomiting, loss of
appetite, weakness, and other signs of illness.
Some of the best and simplest treatments include:
Diet: The Protein Controversy
You may have heard that restricting protein is recommended for pets in kidney
failure. This has been the "standard" treatment for decades in dogs and humans.
However, in cats, it remains controversial.
The real culprit is not protein but phosphorus, which combines with calcium and
gets deposited in the kidneys, causing further damage. Meat contains a lot of
phosphorus, so the easiest way to restrict phosphorus is to restrict meat
protein. Decreasing phosphorus intake (by restricting protein) can help some
pets feel better, so it may be worth a try if the symptoms are a problem.
However, some studies have suggested that excessive restriction of protein in
cats may actually cause further damage to the kidneys and other organs, because
there is not enough protein for normal body maintenance and repair. Experts say
that these diets are not appropriate for cats until the BUN (Blood Urea
Nitrogen) is at least double what it should be normally (about 60-80 mg/dl), and
should never be fed to kittens or healthy cats.
For many animals, a diet with HIGH QUALITY protein will be better than a
low-protein diet. Low-protein diets, if not carefully managed, can lead to
malnutrition. If a low-protein diet is necessary, bear in mind that
non-prescription canned foods are much higher in protein than similar dry foods,
but prescription-type foods typically contain poor quality ingredients.
Canned foods universally contain higher levels of protein than dry foods. Since
dogs are more omnivorous and are better at keeping themselves hydrated than
cats, they may do well with mostly dry food. For dogs, these dry foods contain
less protein:
Canine Caviar Special Needs Adult Dry Dog Food
Canidae Platinum Senior/Overweight Dog Food
Merrick Senior Medley Dry Dog Food
Innova Senior Dog Food
Wellness Super-5 Mix Senior Dry Dog Food
Healthwise Weight Control Dry Dog Food
Over-the-counter canned foods vary tremendously in phosphorus content, from less
than 150 mg to over 600 mg! Veterinary low-protein diets are severely
restricted, containing less than 100 mg of phosphorus per 100 Calories. Click
here for a chart comparing protein, phosphorus, and other nutrients in cat
foods.
Cats are exclusively carnivorous and, because they tend not to drink enough
water, don’t do as well with dry food as a mainstay of their diet. Canned cat
foods containing about 200 mg or less of phosphorus include:
EVO 95% Venison, 95% Chicken & Turkey
Merrick Cowboy Cookout, Thanksgiving Day Dinner
Felidae Chicken & Rice
Wellness Cat Food – Turkey and Chicken
Varieties
Nature’s Variety Beef, Chicken & Turkey, Lamb
Because water balance is so crucial, it is best to feed cats a high-moisture
diet to help maintain good hydration; do not feed only dry food. Feeding mostly
or only canned, raw, or homemade food, even though they tend to be high in
phosphorus and protein, provides the moisture and calories they need, in a very
palatable form that most cats will happily eat. If your veterinarian insists on
a protein-restricted, low-phosphorus renal diets, get the canned version. Adding
egg whites, which contain very little phosphorus, will provide extra protein
without causing harm. Dry cat food causes dehydration even in healthy cats, and
is not appropriate for CRF cats (see the posts on Switching Foods for help).
The best thing you can do is feed a home-prepared diet; but only if the cat will
eat it! If the cat has never eaten homemade food, or does not have a hearty
appetite, this is not a good time to switch! There are several good books on
home cooking for animals, including Dr. Pitcairn's Guide to Natural Health for
Dogs and Cats, by Richard Pitcairn, DVM, and Susan Pitcairn (Rodale Press. ISBN
075962432 and Home-Prepared Dog and Cat Diets: the Healthful Alternative by Donald R.
Strombeck, DVM. (Iowa State University Press. ISBN 0813821495.) If you choose to
use Dr. Strombeck's recipes, I suggest substituting 1 capsule of taurine (250
mg) for the canned clams, since clams do not contain enough taurine for proper
maintenance. For an easy
starter diet.
Several nutritional supplements may be helpful for pets with kidney disease.
Omega-3 fatty acids have been shown to be beneficial in CRF. Be sure to select a
product that contains only omega-3 (pets get plenty of omega-6 in their food),
that is free from contaminants, and doesn’t come from farmed fish such as
salmon.
Nordic Naturals Omega-3 Pet
Only Natural Pet Wild Alaskan Salmon Oil
Nature’s Logic North Atlantic Sardine Oil
B-vitamins help the animal cope with stress and replace water-soluble vitamins
that are lost in the urine. Antioxidants, such as vitamins C and E, are also
important. Potassium supplements may be needed, especially for cats.
Renal Essentials by Vetriscience (for dogs or for cats) is a great all-in-one
supplement that contains herbs, Omega 3 fatty acids, and vitamins B and C.
Recent research shows a benefit from probiotics (friendly bacteria) in cats
with CRF. Kidney blood values (BUN and creatinine) decreased significantly when
cats were given probiotics in canned food.
A newly published paper suggests that melatonin could be helpful in CRF animals;
however the study was done in rats, and appropriate dosages for pets are still
unknown. As new information becomes available we’ll post updates on our
blog, so
check back often!
A nutritional supplement called "Renafood" from Standard Process, is a very good
renal detoxifier and helps to maximize kidney function. Give one or two a day.
Most pets eat them readily if they are crushed into powder and mixed with canned
or homemade food. Call Standard Process at 1-800-558-8740 to find a distributor
in your area. Renafood is a human product that works much better than their pet
products, so be sure to insist on Renafood.
Always consult with your veterinarian before starting your dog or cat on any new
herb or supplement when dealing with kidney disease.
Supplemental Fluids
Your veterinarian can give your pet subcutaneous fluids in the clinic, or teach
you how to give them at home. This is the least intrusive and most beneficial
treatment you can give your pet. Animals in renal failure drink a lot of water,
but they cannot drink enough to compensate for the loss of water through the
kidneys. Subcutaneous fluids are an excellent way to help keep the toxins
flushed out of the bloodstream and make your pet feel much better.
(Click here for detailed instructions)
Holistic Veterinary Care
While no treatment can create new kidney cells when scar tissue has already
formed, homeopathy, herbs, flower essences, or acupuncture may be able to help
your cat feel better and live a better quality of life. Click on this link
for a
directory of holistic veterinary practitioners by state.
It is helpful to reduce stress for any animal with kidney disease. Quality of
life is an important consideration when deciding how aggressively to treat any
disease. Flower Essences can support your companion emotionally and decrease
stress. Flower Essences are completely safe to use along with any conventional
or alternative treatment for kidney disease.
SpiritEssence UR Fine
SpiritEssence Graceful Aging
Pet Essences Kidney Strengthener
Both Chinese and Western herbs can be useful in the beginning stages of kidney
disease. As the disease progresses, consultation with a holistically trained
veterinarian is recommended for proper use of appropriate herbal remedies.
The traditional Chinese herbal formula called
Rehmannia 8 is a classic
combination of herbs used to strengthen kidney function.
Acupuncture can be very useful for animals with kidney disease. Regular
acupuncture can help slow the progression of the disease, stimulate the kidneys
and boost the overall vitality of a dog or cat. To find a practitioner in your
area, visit the holistic
veterinarian directory.
.
Helpful Resources and Links:
Feline CRF Information Center
Holisticat Community
Canine Renal Disease: Danemist – has many helpful links
Additional Resources:
Dr. Pitcairn’s Guide to Natural Health for Dogs and Cats
Veterinarian’s Guide to Natural Remedies for Cats
Veterinarian’s Guide to Natural Remedies for Dogs
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