The purpose of this information I have put together is to assist breeders by providing an update on practical and readily available tests for five problems that affect the breed. This does not mean there aren't other health issues of equal concern, simply that these five are ones we have a means to address right now.
A special THANKYOU for allowing our Bullies to be part of this research and credits go out to DR. CAROLINE O'LEARY for her extensive study into Kidney Disease (HN & PKD), DR. BRUCE MACKAY our Heart Specialist and DR. SUE SOMMERLAD our Hearing Specialist.

Hearing Problems Hereditary Conditions:
Unilateral and Bilateral deafness Mode of Inheritance:
Undetermined, but suspected polygenic recessive with incomplete penetrance. Unilaterally and bilaterally deaf dogs are considered to be equivalent genetically. There is a higher incidence of deafness in the offspring of affected animals.

BAER -- Brainstem Auditory Evoked Response
Results & Interpretation: The BAER test detects electrical activity in the auditory pathway in response to specific stimuli applied to one ear at a time. Both ears are tested separately. Diagnosis of normal bilateral hearing, unilateral (right or left) deafness can be made based on the data.
Screening Age & Frequency:
BAER testing may be done on puppies as early as 6 weeks of age. These puppies can either hear or not hear in both ears. Only one test is needed for verification of hearing status.
Owner Concerns:
Test is not painful to the dog.  Tranquilization or general anesthesia is necessary to be sure that the dog is perfectly still during the test.  Deafness from injury, infection or old age give different results from hereditary deafness.

Kidney Problems in Bull Terriers.
Hereditary Nephritis (Shrinking kidney disease - The silent killer) Renal Dysplasia and Polycystic Kidney Disease - PKD

Mode of Inheritance: AUSTRALIAN research on hereditary nephritis has found it is probably caused by an autosomal dominant gene. There is a high incidence in the offspring of affected animals. There is a variability in the age of onset and progression of the disease.. It is invariably fatal.
Using the BLOOD TESTS (especially the BUN test) for early detection is not recommended as they will only show a positve result when about 75 % of the Kidneys are damaged.

Some symptoms of Kidney problems :
Increased water consumtion (polydipsia)
Frequent urination (polyuria)
Dilute urine (little colour or odor)
Diminished appetite (anorexia)
Weight loss and exercise intolerance
Bad breath (chemical odor)
Nausia and vomiting
Muscle weakness, muscle wasting and shivering
Oral (mouth) ulcers

Test for Nephritis: UP/C (UP:UC) Ratio -- Urine Protein : Urine Creatinine Ratio
This test evaluates the level of protein in the urine, a sensitive indicator for kidney disease. Most laboratories run this test, though not all veterinarians are familiar with it. The test should be carried out on a "mid-stream free catch" sample of urine and should be run concurrently with a standard urinalysis. Urine can also be taken straight out of the bladder using a syringe.

Test Results & Interpretation:
Most authorities around the world accept a ratio of  0.5 and even higher, in Australia a ratio of below 0.3 is normal. It was found many Bullies that tested between 0.3 and 0.5 (the "Grey Area") actually showed signs of HN at a later date. This is why a ratio of under 0.3 is considered "Normal" for Bull Terriers. Testing MUST continue up to the age of 5 years old to rule out "late onset" of this disease. Elevated values should be evaluated more specifically. DIET can lower the UP/C ratio, but not enough to make a big difference overall. Non-kidney sources of elevated protein from infections and even prostate problems must be ruled out and persistent proteinuria established by retesting in one to three months.
An animal with kidney source persistent proteinuria may require a BIOPSY (Nephritis) or Ultra sound for a definitive diagnosis. These animals should not be bred from, but can be treated to maintain their kidney function - for a time, especialy Nephritis.
Recommended for Nephritis (HN) Screening Age & Frequency:
Dogs and bitches used for breeding should be checked from 12 months of age then every six months, or at least yearly and atleast up to 5 years of age.
The UP/C (UP:UC) test is a cheap but affective way for screening on a "free-catch" urine sample to find indications of kidney malfunction. There are a number of problems causing elevated protein in urine. Other more specific tests, some requiring hospitalization, are needed to pinpoint precise diagnosis in some instances. Dogs sicken and die of kidney disease because they cannot clear poisons or retain vital body substances properly. The interval between evidence of proteinuria and full blown renal failure is unknown. As the disease gets worse, treatment becomes progressively more costly and more unpleasant for both dog and owner.

Polycystic Kidney Disease - PKD
Ultrasound of the kidneys is the only way to screen for PKD, preferably by an experienced radiologist. This can be done on a puppy as early as 6 weeks but preferred done at around 12 months of age and only needed to be done once in the animals lifetime.
The signs of PKD are generally roundish fluid filled blisters (cysts) that can be up to 2cm in diameter and can look a bit like "swiss cheese"
Bull Terriers with PKD commonly also have heart defects and can have loose bowel movement - Squirters.

Patella Problems Hereditary Condition:
Patella Luxation Mode of Inheritance:
Undetermined, suspected polygenic, possibly recessive .
Palpation of patellas by a veterinarian. Test Results & Interpretation:
Grade 1 - intermittent, limb carried occasionally, patella easily luxates at full extension of the stifle joint, but returns to position when released.
Grade 2 - frequent luxation, which in some cases, becomes more or less permanent. The limb is sometimes carried. Weight bearing routinely occurs with stifle remaining slightly flexed.
Grade 3 - permanent luxation with torsion of the tibia and deviation of the tibial crest. Animal may use the limb with stifle semi-flexed.
Grade 4 - permanent luxation (resulting from trauma). The limb is carried or the animal moves in a crouched position with the limb partly flexed.

Recommended Screening Age & Frequency:
Certify at 12 months, but Specialist Vets will recommended that the dogs be periodically re-examined as some luxations will not occur until later in life. Yearly testing of patellas is recommended; they can be checked during a regular office visit, which renders yearly evaluation practical as well as highly desirable. Animals should be tested before breeding. Owner Concerns: Feeling the stifle for the location and looseness of the "knee-cap" is a skill. A veterinarian regularly conducting such examinations can usually be very specific about the absence, presence and degree of dislocating knee-cap. The test may cause some discomfort to puppies, as the hind legs must be held tightly in specific positions for evaluation. Grades 2 - 4 can involve discomfort and disability for he dog. Grades 2 - 4 can be treated surgically.

Heart Diseases Hereditary Conditions:
NOTE: It was found early in the study by Dr. Mackay that Bull Terrier Hearts are quite UNIQUE . An inaccurate diagnoses may result if breed specific values are not used.
Aortic Stenosis Mitral Stenosis Ventricular Septal Defects Dilated Cardiomyopathy (suspected) Hypertrophic Cardiomyopathy (suspected) Mode of Inheritance:
Complex; assumed to be polygenic.

Ascultation by a veterinarian with expertise in cardiology or board certified cardiologist. Echocardiogram including Doppler studies.
Interpretation of Test Results:
A phenotypically normal dog is: one without a cardiac murmur, or one with an innocent cardiac murmur that is found to be otherwise normal by virtue of an echocardiograph, including Doppler studies.

Recommended Screening Age & Frequency:
Minimum age of one year for certification and  that testing be done on a "mature" animal. Breeding animals should be checked before breeding and yearly thereafter. Some hereditary murmurs will be detected at a later age but generally by full maturity. Owner Concerns: Heart problems may give very little external warning of their presence until very late in their course, so testing of all breeding stock is a kindness well worth the cost and trouble. Sedation may be required for the rambunctious, as a quiet resting patient is necessary for good reliable readings. Some atypical heart sounds can occur in healthy hearts. Specific diagnosis can require extensive testing and consultation.

Compulsive Tail Chasing & Spinning:

Bull Terrier Neurological Disorder Resources.