Animalia Life

The Breed History
First records for the Bull Terrier date back to 1835 in Britain. Crossing a Bulldog with a White English Terrier (now extinct) is thought to have provided the foundation for the breed. Later, a documented outcross to Spanish Pointer was done to increase size. The white variety was first bred around 1860, and the breed was formally split into the white and colored in 1936. The bull terrier in AKC is registered as the standard size breed, (Bull Terrier) and a miniature size, the Miniature Bull Terrier.

Breeding for Function
This breed was valued as a pit fighter. A very strong constitution, agility and tenacity were bred into them. Over the years, the breeders have worked to make the dog more companionable.

Physical Characteristics
Height at Withers: 21-22" (53-56 cm).
Weight: 52-62 lb (24-28 kg).
Coat: The breed is divided into white and colored types. Hairs are short and hard, lie flat, and have good sheen. For white variety: all white or white with limited markings on the head. For colored variety: other base colors than white, may have white markings; brindle is preferred. They are moderate shedders and have low grooming needs.
Longevity: 11-13 years
Points of Conformation: The distinctive head is long, and the face is full and a curve over the top of the skull to the tip of the nose is present. Ears are close set and small, the leather is thin, and they prick erect when dog is alert. Small dark eyes are deep-set, close-set, and piercing in expression. Oblique in shape, blue eyes disqualify. The nose is black, and the neck is very muscular, long, and not throaty. The thorax is round and deep with very well sprung ribs. The back is short and only slightly arched at the loins. Limbs are straight boned, and moderately long. The feet are compact and well-knuckled. The tapering tail is low set, short, and carried parallel to the topline. The gait is smooth and ground covering.

Recognized Behavior Issues and Traits
Reported breed attributes include: Playful, friendly, active. If they bite, they are reluctant to let go and so must never be teased. Dominant personalities are common. Bull Terriers were bred for fighting so will ably defend and may not get along with all dogs (watch especially for inter-male aggression). They are generally deeply attached to their human family. High activity and exercise needs must be met. If left alone without companionship and mental exercise, they may develop boredom vices. Need to be socialized well to children, and also socialized so that they do not become possessive. They are alarm barkers, not nuisance barkers generally. If off leash, they must be in a fenced enclosure. They may consider small pets as prey. Obedience training is important but keep sessions short to prevent boredom.

Normal Physiologic Variations
May vocalize in grumbles and groans and this is distinct from growling.
Echocardiography: In 14 normal bull terriers, the left ventricular wall thickness was greater and the aortic root diameter smaller than those reported as normal for other breeds of comparable body size. Left atrial dimensions were also larger, however this may have been due to the "maximizing" method of measurement. These dogs also had higher aortic velocities than those reported for other breeds. While these dogs were selected to be as close to normal as possible, the breed may have a particular anatomy that produces abnormal left ventricular echocardiographic parameters. Inaccurate diagnoses of left ventricular hypertrophy and left ventricular outflow tract obstruction may result if breed-specific values are not used.
Echocardiographic Normal Values:
Parameter Mean SD 95% CI
Ao l/a (cm) - 1.9 0.3 1.3-2.5
Ao s/a (cm) - 2 0.2 1.6-2.4
LVld (cm) - 3.8 0.3 3.2-4.4
IVSa (cm) - 1.3 0.2 0.9-1.7
IVSd (cm) - 1 0.2 0.6-1.4
LVFWa (cm) - 1.2 0.1 1.0-1.4
LFVWd (cm) - 1 0.1 0.8-1.2
FS% - 32.5 4.5 24-41
SV (mL) - 38.2 7.3 24-53
HR (beats/min) - 130.9 22.5 86-176
Weight (kg) - 22.9 3.7 *
AoV (m/s) - 1.9 0.2 1.5-2.3
SD standard deviation, CI confidence interval, Ao aortic annular diameter, l/a long axis, s/a short axis, LVl left ventricular internal dimension, d diastolic, IVS interventricular septum, s systolic, LVFW left ventricular free wall thickness, FS% fractional shortening, SV stroke volume, HR heart rate, AoV aortic velocity
Parameter Weight (kg)
20/25/30
LA l/a (cm) - 2.5-3.4/2.8-3.7/3.1-4.0
LA s/a (cm) - 2.2-3.5/2.5-3.8/2.8-4.1
LVls (cm) - 1.9-3.0/2.2-3.2/2.4-3.5
LA is left atrium diameter, l/a is long axis view, s/a is short axis view, LVls is left ventricular internal dimension during systole

Drug Sensitivities
None reported

Inherited Diseases
Hip Dysplasia: Polygenically inherited trait causing degenerative joint disease and hip arthritis. OFA reports 6.7% affected.
Patella Luxation: Polygenically inherited laxity of patellar ligaments, causing luxation, lameness, and later degenerative joint disease. Treat surgically if causing clinical signs. OFA reports 2.1% affected. Reported at a frequency of 2.84% in the 1997 BTCA Health Survey.
Hereditary Nephritis: Autosomal dominant disorder causing renal failure at variable ages in affected dogs due to abnormal kidney basement membrane protein and structure. Dorn reports a 8.16x odds ratio for kidney disease versus other breeds. No genetic test is available.
Polycystic Kidney Disease (PKD): Autosomal dominant caused by an undetermined mutation in the PKD 1 gene. Renal cysts are diagnosed by ultrasound. They are usually bilateral, from less than 1 mm to over 2.5 cm in diameter, and occur in the cortex and medulla. Causes chronic renal failure. Dorn reports a 8.16x odds ratio for kidney disease versus other breeds. No genetic test is available.
Elbow Dysplasia: Polygenically inherited trait causing elbow arthritis. Too few Bull Terriers have been screened by OFA to determine an accurate frequency.
Lethal Acrodermatitis: An autosomal recessive disease. Affected dogs present with stunting, splayed digits, eating difficulties, skin disease of the face and feet, and increased susceptibility to microbial infections. In older dogs, paronychia, nail disease and hyperkeratosis of the footpads develops, becoming severe in dogs over six months of age. Median survival time is 7 months. Although many of the clinical signs and the pathology of this condition suggest zinc deficiency, the measurement of blood zinc levels as a diagnostic aid is of limited value, and the dogs do not respond to zinc treatment. Reported at a frequency of 0.81% in the 1997 BTCA Health Survey. No genetic test is available.
Disease Predispositions
Allergic Dermatitis: Inhalant or food allergy. Presents with pruritis and pyotraumatic dermatitis (hot spots). Bull Terriers are at an increased risk versus other breeds, especially white Bull Terriers. Reported at a frequency of 25.56% in the 1997 BTCA Health Survey.
Compulsive Tail Chasing and Spinning: Disorder of persistent spinning observed in the breed. Possibly a behavioral compulsion, as 75% of affected dogs respond to clomipramine administration. However a neurological partial seizure disorder cannot be ruled out, as some dogs have abnormal electroencephalograms and respond to anticonvulsants. Compulsion was reported at a frequency of 18.05%, and spinning 17.65% in the 1997 BTCA Health Survey. Unknown mode of inheritance.
Deafness: Congenital deafness can be unilateral or bilateral. Diagnosed by BAER testing: Strain reports total (uni or bilateral) deafness frequency of 19.9% in white Bull Terriers, and 1.3% in colored Bull Terriers based on BAER testing. 9.9% of all Bull Terriers test unilaterally deaf, and 1.1% test bilaterally deaf.
Persistent Pupillary Membranes: Strands of fetal remnant connecting; iris to iris, cornea, lens, or involving sheets of tissue. The later three forms can impair vision, and dogs affected with these forms should not be bred. Identified in 7.84% of Bull Terriers CERF examined by veterinary ophthalmologists between 2000-2005.
Hypothyroidism: Inherited autoimmune thyroiditis. 7.0% positive for thyroid autoantibodies based on testing at Michigan State University. (Ave. for all breeds is 7.5%).
Primary Lens Luxation: Occurs in the breed due to abnormalities of the suspensory apparatus of the lens (zonule). Often progresses to secondary glaucoma. Relative risk of 65.88x versus other breeds. Identified in 5.88% of Bull Terriers CERF examined by veterinary ophthalmologists between 2000-2005. Unknown mode of inheritance. CERF does not recommend breeding any Bull Terrier with lens luxation.
Cataracts: Anterior, posterior, intermediate and punctate cataracts occur in the breed. Identified in 3.92% of Bull Terriers CERF examined by veterinary ophthalmologists between 2000-2005. CERF does not recommend breeding any Bull Terrier with a cataract.
Mitral Valvular Stenosis/Left Ventricular Outflow Tract Obstruction (LVOTO): Found at an increased frequency in Bull Terriers. Echocardiography is a much more sensitive test than auscultation for murmurs. Pathological findings can include thickened, nodular, and stiff mitral valves with short, thickened, and fused chordae tendineae. Myxomatous valvular degeneration, small vessel arteriosclerosis in the myocardium and fibrosis of cardiac conduction tissue were common histologic findings in Bull Terriers with clinical cardiac disease. An increased incidence was found in Bull Terriers affected with PKD, though it could not be identified if there is a direct genetic correlation between the two disorders.20,21,22 Aortic Stenosis: Found at an increased frequency in Bull Terriers. Clinical signs can include syncope, exercise intolerance/fatigue, or heart murmur. Cardiac ultrasound shows thickened and/or poorly opening aortic valve leaflets, and an elevated blood flow velocity through the aortic valve annulus (mean v=5.2m/s; range=4.8-5.9). Varying degrees of concentric LVH and mitral valve thickening can be seen. Many affected bull terriers have concurrent severe mitral valve stenosis.
Demodicosis: Demodectic mange dermatitis has an underlying immunodeficiency in its pathogenesis. Dorn reports a 2.14x odds ratio versus other breeds. Unknown mode of inheritance.
Actinic Keratosis: Affected dogs present with alopecia, erythema, comedones, scales, excoriation, pustules, epidermal collarettes, crusts and scars, with pathologic development of epidermal hyperplasia, parakeratosis, and orthokeratosis. Lesions occur secondary to prolonged UV/sunlight exposure, and may be a precursor to squamous cell carcinoma. Seen at an increased frequency in the breed.
Retinal Dysplasia: Focal dysplasia and retinal folds are recognized in the breed, which can lead to retinal detachment. Reported in 1.96% of Bull Terriers CERF-examined by veterinary ophthalmologists between 2000-2005.
Vitreous Degeneration: Liquefaction of the vitreous gel which may predispose to retinal detachment. Identified in 1.96% of Bull Terriers CERF examined by veterinary ophthalmologists between 2000-2005.16 Inverted Canines: In affected Bull Terriers, the mandibular canine teeth are tipped (curved) caudally and impact at the mesio-palatal gingival margin of the maxillary canine teeth.
Cerebellar Abiotrophy, Cerebellar Vermian Hypoplasia, Cleft Lip/ Palate, Deep Pyoderma, Ectropion, Entropion, Inguinal Hernia, Keratoconjunctivitis Sicca, Laryngeal Paralysis, Osteochondritis Dessicans-Hock and Stifle, Progressive Retinal Atrophy, Prognathism, Prolapsed Nictitans, Retained Primary Teeth, and Wry Mouth are reported.

Isolated Case Studies
Sick Sinus Syndrome: A 6.5-year-old, spayed female bull terrier was investigated for episodic weakness and a syncopal episode. Resting ECG revealed bradycardia (40 to 60 bpm), sinus pauses of typically 2-4s, atrial premature contractions (APCs), and junctional escape beats. Vagal maneuvers did not result in significant sinus pauses, and atropine response was normal in rate but not rhythm, implying a conduction disturbance rather than excessive parasympathetic tone.

Genetic Tests
Tests of Genotype: Direct test for color alleles is avaiable from VetGen.
Tests of Phenotype: CHIC certification: Required testing includes patella examination, cardiac evaluation (recommend echocardiogram), BAER test for deafness, and kidney disease screening with urine protein:creatinine ratio. (See CHIC website; caninehealthinfo.org).
Recommended tests include CERF eye examination, hip and elbow radiographs, and thyroid profile including autoantibodies.

Miscellaneous
- Breed name synonyms: English Bull Terrier, White Cavalier (for white variety)
- Registries: AKC, UKC, CKC, KCGB (Kennel Club of Great Britain), ANKC (Australian National Kennel Club), NKC (National Kennel Club)
- AKC rank (year 2008): 57 (1,900 dogs registered)
- Internet resources: Bull Terrier Club of America: btca.com
The Bull Terrier Club of Canada: thebullterrierclub.ca
The Bull Terrier Club (UK): thebullterrierclub.com