PET HEALTH BULLETIN
Winter 2013
1. Renal Disease in Cats and Dogs
Kidney disease is one of the most common
conditions affecting older pets, especially cats.
Recent studies have shown that one in five
cats above the age of fifteen has kidney
disease.
What do kidneys do?
The kidneys are a vital organ in our pet’s
body. They are responsible for many jobs all
necessary for keeping our pet healthy.
Kidneys regulate the internal water balance of
the body to keep it hydrated. They also
produce renin which helps maintain blood
pressure. Kidneys are also responsible for
excretion o f waste products. Kidneys produce
erythropoietin which is necessary for
producing red bloods cells. Older pets might
also be on medication for other medical issues
and the kidneys excrete some of these drugs
out of their body.
What causes kidney disease?
Kidney disease can be due to many causes. In
our older pets, it is often due to a
degeneration of kidney tissue as a result of
age. This disease usually progresses slowly.
Other less common causes include exposure
to certain toxin, severe bacterial infection,
tumors or a flaw in the immune system.
Occasionally, some animals can also be born
with cysts within their kidneys which can
affect the function of the kidneys.
What are the signs of kidney disease?
One of the first signs of kidney disease is
frequent urination. As the kidneys are unable
to help the body to retain water, animals with
kidneys disease tend to urinate more. An
excessive amount of drinking is then initiated
in an attempt to replace loss of body water
due to frequent urination. Diseased
kidneys cannot effectively eliminate
waste. Toxic chemicals such as urea
and creatinine accumulates which
cause nausea and can lead to
vomiting. Weight loss is common as
well due to poor appetite. Low
erythropoietin levels affects
regeneration of red blood cells and
anemia results. Bad breath, mouth
ulcers and blood in their feces are
some of the other signs you might
notice in advance kidney disease. If
there is an underlying urinary tract
infection, you might also notice
some sign of straining and blood in
the urine.
How do we manage kidney
disease?
Although kidney disease is usually
irreversible, it is manageable. The
aim of the treatment is to preserve
as many functions of the kidney and
delay further progression of kidney
disease. If well managed, we can
greatly improve our pets quality of
life.
The treatment usually varies
according to the severity of the
disease. It can range from simple
dietary modification, daily
medication to hospitalization for
several days in more advanced
kidney disease cases.
One of the cornerstones for
managing kidney disease is dietary
modification. Animals with kidney
failure need to be on a diet that is
relatively low in protein. This
reduces the burden placed on the
kidneys to excrete urea which is a
waste product of protein. Feeding
protein with high biological value is
encouraged as it will be used by the body to
build new tissue rather than be excreted.
Examples of high biological value protein are
those found in diary products (i.e. milk,
cream, cheese etc.), eggs and organ meats
(i.e. liver and kidney). Fish and lean meat such
as chicken, rabbit or mince are best avoided.
However, the best diets for animals with renal
failure are veterinary prescription diets,
including Hill/s prescription diet k/d and Royal
Canine renal support. They are balanced and
tailored to the special requirements of kidney
failure patients. In addition to having the right
amount and type of protein for renal failure
cases, they contain a larger proportion of
omega fatty acids which improve renal blood
flow and fight renal inflammation. These
commercial diets are also lower in
phosphorous which help delay the
progression of kidney disease. Lower sodium
levels in these foods also help in managing
blood pressure which prolongs its remaining
kidney function. Vitamin B is also
supplemented in this diet to replace the
increase loss in the urine. Prescription diet
contains higher levels of soluble fiber which
helps lower the blood urea level by limiting
ammonia adsorption from the bowel.
When dietary modification is not enough,
your pet may have to start taking daily
medication. Often this will be a once a day
tablet called Fortekor .Fortekor stops
production of an enzyme that can lead to
harmful effects on kidneys. It dilates blood
vessels and so reduces the pressure in the
kidneys which in turn reduces the amount of
damage done to the kidneys.
In severe cases, when your pet stops eating
and starts vomiting, hospitalization is
essential and fluid therapy is commenced for
several days. This would help to correct the
electrolyte imbalance and reduce the level or
urea and creatinine in the blood.
Hypertension (increase blood
pressure) secondary to renal
disease needs to be addressed to
prevent blindness or stroke.
Norvasc , a medication may be
prescribed to lower the blood
pressure in certain cases.
Mirtazapine and Cryoheptadine are
oral tablets that reduces nausea
and help stimulates appetite. Low
potassium levels in the blood can
also be eliminated with the use of
oral supplementation. If your pet is
already on a renal diet and the
blood phosphorous levels is still
high, there are phosphate binders
that can be taken to reduced
phosphate in the diet. Frequent
monitoring is essential to monitor
the progress of kidney disease. We
recommend that they be seen every
6 months for a blood test to
measure the level of blood urea,
creatinine, potassium, and sodium
and phosphorous. Blood pressure
should also be checked at each visit.
It also provides your vet with an
opportunity to asses hydration of
your pet at each visit. Monitoring
muscle mass and hydration is also
essential.
Kidney disease is irreversible and
progressive but we can manage the
condition with moderate dietary
changes and the use of medication,
as required. This allows our older
pets to live a longer and better
quality of life.
Clinic news
We would like to welcome Joanne
Sattler, an aspiring Cert 4 vet nurse
to join our team.