Bull Terrier: hereditary nephritis is picked up by a urine test
The Bull Terrier has a reputation for being a solid dog, and it is. Its real fragility is silent: an inherited kidney disease that progresses for years without a single visible sign, and which a simple urine test detects long before. Our piece on compulsive tail chasing in the Bull Terrier covers the breed's other big topic; this one tackles the kidney.
Dominant inheritance, and therefore visible in the pedigree
This is what makes the disease unusual. Work by J. Hood and colleagues, published in 1990 in The Veterinary Record on a family of 33 Bull Terriers with renal failure, established the mode of inheritance: every affected offspring had at least one affected parent, the sex ratio was balanced, and no generation was skipped — the signature of an autosomal dominant gene (study on Google Scholar). The practical consequence: unlike recessive conditions, there is no "healthy carrier". A dog that has the gene will develop the disease, sooner or later, and will pass it to half its offspring on average.
The canine model of Alport syndrome
The study by J. C. Hood, J. Savige, A. Hendtlass, M. M. Kleppel, C. R. Huxtable and W. F. Robinson, published in 1995 in Kidney International, compared the bull terrier disease with the human forms of Alport syndrome (study on Google Scholar). The authors describe ultrastructural abnormalities of the glomerular basement membrane, frequent haematuria and, in some dogs, anterior lenticonus — a lens deformity. One notable difference from humans: deafness does not accompany the renal disease in dogs. The delay before overt renal failure varies enormously, from eleven months to eight years, which explains how a dog can be bred before its disease shows.
Screening comes down to one sample
Because proteinuria long precedes clinical signs, the reference test is the urine protein to creatinine ratio, or UPC. Usual veterinary thresholds place the proteinuric zone above 0.5, with a borderline band between 0.2 and 0.5. A high result should be rechecked on several samples before concluding, and puppies under three months are unreliable, as transient proteinuria is common at that age. The principle adopted by breed clubs is straightforward: a UPC every year from one year old, and always before any mating. In a Bull Terrier, a dipstick alone is not enough.
Not to be confused with polycystic kidney disease
The Bull Terrier carries two distinct inherited kidney diseases. The study by C. O'Leary and colleagues, published in 1999 in the Australian Veterinary Journal, describes a polycystic kidney disease in the breed that is also autosomal dominant, but detected by ultrasound rather than urine (study on Google Scholar). A complete renal work-up in the breed therefore combines both examinations. The general profile is on the Bull Terrier breed page, and other follow-up points in our dog care and grooming section.
What it weighs on a budget
Chronic renal failure means a therapeutic diet for life, regular blood work, sometimes fluid therapy. It often sets in after several years: the policy must therefore exist well before the first abnormal UPC, or the kidney becomes an exclusion. Our benchmarks are on insuring a Bull Terrier.
Frequently asked questions
From what age should the first UPC be done?
From one year old, then annually. Below three months the result cannot be reliably interpreted.
Does a high UPC mean inherited disease?
Not necessarily: a urinary infection, fever or recent exercise all raise the ratio transiently. It is the repeated result that counts.
Can the disease be slowed?
It cannot be cured, but a renal diet, blood pressure control and treatment of proteinuria push back renal failure. Hence the value of early detection.
This guide is part of Planète Pets’s Dogs universe. Our advice is general in nature: for any health concern, your veterinarian remains the only reference.