The NBTC(A) have now designated the following as known
hereditary health problems affecting the Bull Terrier breed :
Polycystic Kidney Disease
Hereditary Nephritis
Inherited Heart Disease
Deafness (Unilateral and Bilateral)
Luxating Patella
Primary Lens Luxation (Bull Terrier (Miniatures) only)
This does not mean that these are the only hereditary health problems in the breed, it’s
just that they are the ones being currently addressed.

Inherited Kidney Disease in Bull Terriers By Dr Caroline O'Leary
University of Queensland
Inherited Kidney Disease (IKD) has been reported in many breeds of dogs including
the Bull Terrier and Miniature Bull Terrier as well as in people.
There are many different types of kidney disease, inherited (or genetic) faults being only one cause. Infections, poisons, some drugs, non-genetic cancers, liver, pancreas, uterine, heart disease or many other diseases can all cause kidney diseases.
The inherited conditions in Bull Terriers can occur in very young (less than six months) middle-aged or very old animals. Some dogs can be 10 years old plus and have the faulty gene in their makeup, pass it on to some of their pups, and may appear normal to their owners. These animals may live to a ripe old age with no one suspecting they
have the diseases or have passed it on to their pups.
Signs of kidney failure that are common to both types of IKD and to other causes of kidney failure include the following:
poor appetite
dullness or lethargy
weight loss or stunted growth
poor hair coat
vomiting/diarrhoea
foul breath and mouth ulcers
muscle twitching and convulsions
drinking excess water and passing too much urine – owners often notice an increase in the urine passed overnight.
Pale gums (anaemia)
Dehydration (sticky dry gums)
There seem to be two types of IKD in Bull Terriers.
The first type is polycystic kidneys where the kidneys contain fluid filled cysts (or balls of fluid) which can be seen by looking at the kidney, for example by using an ultrasound machine, as black "holes" inside the kidneys. At what
age this commonly is first detectable is unknown. While it is possible to detect the
defect in some dogs as puppies, it may be that in animals it is not obvious until
the dog is much older. In this disease a urine test will not pick all affected dogs,
so an ultrasound examination is ideal.
The second condition is nephritis where the kidneys may look fairly normal until a
biopsy (or small piece of tissue taken from a live animal) is examined under a microscope.
It is not possible to diagnose this disease on the basis of only an ultrasound examination.
A urine test or kidney biopsy are the best tests for this disease.
Both conditions are thought to be inherited by an autosomal dominant fashion, which means that
only one parent has to have the fault for half the litter to be affected. If both parents
have the fault three-quarters or more of the pups may be affected.
Because of the way these conditions are inherited, there is no point in condemning
whole kennels or blood lines. As an affected dog may produce many unaffected pups
and these animals do not have the faulty gene/s, these animals are fine to breed with
as long as they are regularly tested. They have the virtues present in the lines but
without the ‘taint’ of the faulty gene/s.
Dogs that have either of these inherited problems SHOULD NOT be bred from.
There is no test available that can say for sure that dogs are unaffected below
one year of age. It is possible some affected dogs are not detected until they are 3
or 4 years old. Even leaving the ethical problems out of deliberately breeding affected
dogs that must be euthanised or given to homes with the knowledge that they are affected
by a deadly genetic disease, these dogs cannot be reliably cleared until they are at
least 1 year old and possibly 3-4 years old. These dogs would have to be kept until this age before being bred.
Dogs affected by both these conditions may have bloody urine on and off, and the vast majority of
dogs with nephritis and some of the dogs with polycystic kidneys will have abnormal levels of protein
in their urine (this is shown by a high U P/C or urine protein to creatinine ratio). Only a few
who are late in the course of the disease will have abnormal blood results. In both these conditions,
how fast the disease progresses and how severe it is varies from dog to dog.
The Urine Protein to Creatinine ratio (U P/C) is a very sensitive test and is
valuable in detecting nephritis and some polycystic kidney disease before signs of kidney failure appear (so lengthening the dog’s good quality of life)
and hopefully before the dog is bred. Using this test will hugely
decrease the nephritis
problem within one generation. This is especially so as it is possible to prevent
popular affected stud dogs spreading the faulty gene/s widely by detecting them much
earlier than was possible before with the BUN test.
Animals with a high U P/C need to have a full urinalysis completed to rule out other causes than
inherited kidney disease. If the U P/C is high and there are no other obvious causes (e.g.
reproductive problems, bladder problems) an ultrasound examination and possibly a kidney
biopsy will give the full answer.
The U P/C is easy to use and relatively cheap, making it an ideal screening test
for nephritis. We believe most of those affected Bull Terriers have a high U P/C result by the time they are about a year old. There are possibly occasional
dogs that are affected, that only have a high U/PC once they are 3-4 years old, but
there are no published records of this. Lifetime retesting is
recommended at this stage.
A lot more work needs to be done to investigate both these diseases. The relationship
between these two diseases needs to be looked at, the value of current testing
procedures needs to be continually monitored and, hopefully, in the future a genetic
test will be developed that can be done once in young pups to predict which ones have
the faulty gene/s.
There is no effective cure for either condition. Prevention by breeding dogs
free of these inherited faults is the best solution.
At this stage palliative treatment to maintain comfortable life for as long as
possible is the usual treatment for IKF.
If the kidney failure is recognised early in its course the following can be tried:
constant access to fresh water.
controlled protein, phosphorous and salt diet (use only with care in growing dogs).
phosphate binders to bind phosphorous in the diet.
water soluble vitamins (especially B vitamins).
hormones for anaemia.
medication for nausea and stomach ulcers.
blood pressure medication if necessary.
Some of the reasons so little is known about inherited diseases include:
hard to detect carriers of faulty genes cheaply, accurately and early in life before dogs
are sold or used for breeding.
Differences between dogs in the way the disease appears.
Need for commitment from the Breed Clubs to support research into the problem and develop strategies to breed soundly.
A certificate system to encourage breeding from unaffected dogs and a National Register appears to be the best solution.

Deafness
There are three deafness classifications,
Normal bilateral hearing
Unilateral deaf (deaf in one ear), and
Bilaterally deafness (deaf in both ears)
The only conclusive test for differentiating between normal and abnormal hearing is the BAER/BAEP test (Brainstem Auditory Evoked Response or Potential).
Testing can be done as early as 5 to 6 weeks of age. Only one test should be needed for verification of hearing status.
Deafness can occur in both white and coloured bull terriers.
Both unilaterally and bilaterally deaf dogs are genetically equilivant i.e breeding
a unilateral is the same as breeding a totally deaf dog.
Mode of Inheritance:
The exact mode of inheritance is not yet known but it is believed to be recessive in nature
and with probably more than one gene involved.
The first step in reducing deafness is to remove all unilaterals from the breeding population.

Luxating Patella (Slipping Patella)
Q. What is luxating patella? (Slipping patella)
A. It is the failure of the patella (kneecap) to remain in the groove provided for it in
the front of the lower end of the thigh bone (femur),usually slipping to the inside, but rarely
to the outside.
Q. Why does (can) it slip?
A. There are two reasons, and both are usually present in an affected dog.
1. The grove may be too shallow, or tilted to one side too much.
2. The thigh bone may be twisted and/or bent at the bottom or top, so that the thigh muscles pull the patella out of its groove.
Q. What causes these defects?
A. Shallowness of the grove is largely hereditary, though it is aggravated by faulty muscle
pull. Twisting or bending of the thigh bone is partly hereditary and/or partly nutritional
and/or partly due to use of or stress on the leg.
Q. What is the role of the thigh muscles in the trait and the resulting disease?
A. Muscles are under constant tension (tone) to retain their readiness for action and to
help to stabilise normal joints. This tone is quite powerful and capable of bending , twisting
and deforming bones which are not properly conformed in the first place. You have noticed the
spinal deformities of hunchbacked people.... these are primarily due to the muscles’ pull on
the bones only slightly misshapen to begin with. Bone is strengthened in normal structure by
the muscle tone, but constant tension on misshapen bones greatly multiplies deformity.
Q. What is the effect on my dog?
A. The effect varies from none to severe lameness.
Q. What determines how bad it will be?
A. The degree of inheritance from each parent, the amount of bone deformity and/or groove
deficiency, the activity of the dog (especially its acrobatic tendencies), and its age (older is worse).
Q. When can I tell ?
A. If all dogs are examined by an experienced veterinary orthopaedist at 4-6 months, the presence
and the degree of the trait can be detected. At this time, a projection of the possible severity can
be graded:
Grade 1 - Patella is found in its groove, can be manually shifted out of its groove, but returns
at once spontaneously and never displaces (slips) spontaneously.
Grade 2 - Patella is found in its groove, can be manually shifted out of its groove, but does not immediately spontaneously return and will stay displaced for few steps or moments.
Grade 3 - Patella is found out of its groove, but can be replaced in the groove manually.
Grade 4 - Patella is found out of its groove and cannot be replaced in the groove manually.
Q. How does it affect the dog?
A. All Grade 3 and Grade 4 and some Grade 2 will become arthritic in the stifle (knee) at maturity
or later, due to the cartilage damage to the patella and edge of the groove resulting from use and
wear in the displaced (slipped) configuration. Some dogs will be affected more than others.
Q. Can it be treated?
A. Grades 2 and 3 can be helped by orthopaedic surgical procedure to improve the groove and/or
straighten the thigh bone, and/or redirect the pull of the muscles. While this may make the
individual dog more comfortable, it doesn’t cure the genetic defect, which can only be managed
by not breeding from animals in Grade 2, 3 or 4 and selecting mates which are free from the trait for Grade 1 in animals.
Q. How can I tell if a Bull Terrier has Slipping Patella?
A. Only a qualified examination is accurate. You can’t tell by looking. Hind leg lameness
and hitching can be caused by dozens of different things, many of them temporary, such as a
cut pad or a pulled muscle. Straight stifles, bowed out stifle joints, or overbent stifles
do not necessarily have the combination of defects which cause slipping patella.
Q. What can I do to reduce the increasing incidence of this painful inherited defect in Bull Terriers?
A. 1. Have your dog examined by a qualified veterinarian, preferably one who specialises in orthopaedics.
2. If your dog is affected, send a copy of the report to the breeder of your dog.
3. The incidence of slipping patella in Bull Terriers can be reduced dramatically if affected animals are not used for breeding.
4. Owners of stud dogs are encouraged to have their dogs examined by a qualified veterinarian and provide a certificate of the results of that examination if the bitch owner asks for it.
5. Brood bitch owners are encouraged to have their bitches examined and to provide a certificate of the results if the stud dog owner asks for it.
Q. Do these certificates guarantee that I will have no Slipping Patellas in my litter?
A. No. What it does guarantee is that it will dramatically reduce your chances of getting puppies with slipping patella’s in your litter.
Due to the fact that slipping patella is caused by a combination of inherited defects, it is
difficult to completely eliminate it from ever happening. However, breeding animals together who
already have the defects in combination increases the chances of having it in your puppies, as
does linebreeding to common ancestors who were affected with slipping patella.
Q. How can I make a difference when other people don’t seem to care?
A. Every decision not to breed an animal with slipping patellas takes one more potential
producer of this painful affliction out of circulation. The number of concerned breeders is on the
increase and with a concerted effort the incidence of slipping patella’s in Bull Terriers can
be reduced by an enormous percentage.
1. You can personally educate other Bull Terrier owners (all of whom are potential breeders) who
may not be aware of the problem by giving them a copy of this brochure.
2. You can ask for proof of examination from the owner of the Bull Terrier which you are mating to your dog.
3. You can raise the consciousness of other owners that you meet elsewhere.
4. You can contact a Club Committee member if you have any suggestions or comments.
You can make all the difference in your own breeding program and, with enough responsible breeders,
the breed will benefit a thousandfold. You will make a difference.
Reference/Acknowledgement: Bull Terrier Club of America’s information handout. |