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Bull Terriers suffer from
various forms of Heart Disease, the two most common are mitral valve and
the aorta, these are explained in more detail below.
Both these conditions
are
inherited, however there are tests available to ensure your dog is not
suffering from these conditions.
Very few breeders use
these tests, why? I can not answer.
A vet can listen to your
dogs heart but a slight murmur can easily be missed, your dog may be
excited or stressed so the heart beat changes or it just can not be
heard through a general stethoscope. Of course what starts as a small
murmur can change very quickly to become a serious health risk to your
dog.
I have tried to keep the
information below simple where possible and added diagrams to help. In
order to understand the heart disease suffered by the Bull Terrier it is
important that you first understand how the heart works.
Please read on to find
out more!
The heart
explained
The heart acts as the
bodies pump pushing blood around the body in order to keep the vital
organs oxygenated.
The heart is divided into
four chambers, two upper atria, which receive venous blood, and two
lower ventricles which eject blood into arteries. The right ventricle
pumps blood to the lungs, where the blood becomes oxygenated, the left
ventricle pumps oxygenated blood to the entire body. The proper flow of
blood within the heart is aided by two pairs of one-way valves placed in
tissue between the atria (upper chambers) and ventricles (lower
chambers).
These one-way valves are
known as the atrioventricular (AV) valves. The AV valves located between
the right atrium and right ventricle has three flaps and is therefore
called the tricuspid valve. The AV valve located between the left atrium
and left ventricle has two flaps and is thus called the bicuspid valve,
or better known as the mitral valve.
Please see the diagram
below as this will help you understand the above text.
Oxygen rich blood in the
left atrium enters the left ventricle and is pumped into a very large,
elastic artery - the aorta. The aorta ascends for a short distance,
makes a U-turn, and then descends through the chest and abdominal
cavities. Arterial branches from the aorta supplying oxygen rich blood
to all the organ systems.
I am sure you can now
imagine how serious it is if the mitral valve or aorta do not work
properly in your Bull Terrier.
The common
diseases affecting the Bull Terrier
The common heart
conditions affecting the Bull Terrier are Mitral Valve Displasia
- affecting the mitral valve and sub-aortic stenosis -
affecting the aorta.
As explained above the
mitral valve acts as a one way valve stopping the blood flowing
backwards, when the mitral valve is damaged blood leaks back and thus
causes the heart to work harder. This condition is known as mitral valve
displaisia. The harder the heart works the lager it becomes, the worse
the condition becomes the harder the heart works until eventually it can
not cope and gives in, stopping completely.
A similar thing happens
when the aorta is diseased, the aorta narrows at the point it leaves the
heart thus the heart works harder to pump the blood through. This
condition is known as sub-aortic
stenosis. Again the harder the heart works the larger it becomes until
eventually it can not cope and gives in.
The damage caused by both
of these conditions is irreversible and will deteriate as your dog gets
older. Medication can be given to slow down the disease and thus
increase your dogs life however, your dog will require medication and
vet trips for life and you may have to restrict exercise and play
depending on the severity. The end result for both conditions is death,
normally occurring before your Bull Terrier reaches double figures.
As both conditions cause
the heart to beat irregularly the condition can be heard as a heart
murmur.
What is the
correct test?
Many vets are unable to
detect a small murmur so the appropriate tests for these diseases will
need to be carried out by a qualified Cardiologist. There are various
ways to detect heart murmurs, either by auscultation (listening with a
special stethoscope), if they are still uncertain they may well use a
doppler ultrasound scan. The doppler scan looks inside the beating heart
and is similar to a pregnancy scan in people. These test are non
invasive and normally sedation is not required.
Heart murmurs are graded
from 1 (very mild) to 6 (very serious). A certificate is issued showing
either no murmur present or which grade murmur has been detected.
Young puppies can
sometimes have an innocent murmur which disappears as they grow, it is
therefore not recommended to test your bull terrier until they are at
least 1 year old and yearly thereafter.
Your vet will refer you
to your local Cardiologist.
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Please click the picture
above to see what the certificate should look like. Check name of dog &
that it is less than 1 year since examination was carried out.
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A
healthy canine heart, the mitral valve |
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A
diseased canine heart, the mitral valve |
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Symptoms of
heart disease
Similar to kidney disease
the symptoms can easily be missed or non showing. If your dog only has a
slight murmur (grade 1 - 3) its likely that no signs will be shown and
you will be completely unaware. Again the vet may not notice this and
give the all clear when infact it is not. This is why the above tests
are so important.
As the disease deteriates
the signs tend to include:-
It is important to catch
heart disease early so medication can be given at the earliest time
possible. This will help reduce the degeneration of the heart thus
helping your bully to live a longer, more comfortable life. If you are
unaware of heart disease until the heart is seriously damaged medication
will do little to help, once the damage is done it is irreversible.
Bullies have been known
to die young and old due to heart disease, there is no age limit for the
onset or final stages of the disease.
How is it
inherited?
It is still uncertain how
this disease is inherited, however is believed to be a recessive gene,
this means whilst some dogs never actually develop a heart condition
they carry the genes and pass these onto their puppies. If these dogs
are then bred with another carrying the gene they can produce puppies
who develop heart disease, however more research is required into this
theory. If you breed from a Bull Terrier with a heart condition it is
highly likely that some puppies will inherit the condition and in many
cases worse than the parent. Bull Terriers with this condition should
not be used in breeding programs until further research has been done.
Research is currently
underway in another breed which also suffer with mitral valve disease to
try and find the marker gene causing this disease, hopefully once this
has been detected it will be much easier to find in the Bull Terrier and
a simple DNA test will determine those dogs clear, carrying or having
mitral valve disease. We will update this page as more information
becomes available.
How common is
it?
Some Bull Terrier Clubs
ran heart screening at their shows, the results were astonishing. It became apparent that
25% - 40% of Bull Terriers (dependant on the area) screened had heart
murmurs. This shows how serious heart disease is in this breed.
Please ask the breeder
for the certificate from a Cardiologist showing the Sire and Dam of the
puppies have been cleared of heart disease.
Your vet will refer you
to your local Cardiologist.
Author:- Debbie Wiles
If you would like any
further information on heart conditions affecting the Bull Terrier
please feel free to email us on contact button at top of page.
NOTE: INFORMATION SUPPLIED
ON THIS PAGE IS FOR INFORMATION PURPOSES ONLY. IF YOU SUSPECT YOUR DOG
HAS ANY OF THE ABOVE SYMPTOMS OR PROBLEMS PLEASE SEEK THE ADVICE OF YOUR
VET. |
