Bull Terrier Polycystic Kidney Disease
Bull Terrier polycystic kidney disease is a progressive and irreversible kidney disease that often results in renal failure. It is a breed-specific syndrome in Bull Terriers. Similar conditions have been identified in Golden Retrievers, Blue Merle Collie and West Highland White Terriers. Bull Terrier polycystic kidney disease was for the first time reported in 1994. Other than BTPKD, another kidney disease affecting the Bull Terriers Hereditary Nephritis, but they differ in disorder characteristics and genetics.
Kidneys are organs important for regulating the plasma and tissue fluid in the body. This is achieved with kidney’s filtering of toxins out of the body by the formation of urine. With formation of urine, also other important values are being regulated, such as the volume of blood plasma, concentration of waste products in the blood, concentration of electrolytes in the plasma and plasma’s pH. When the kidneys do not function properly and are not able to perform their primary function, the toxins will remain in the body, concentrate in the blood, causing also rising of the blood pressure and consequently stress to other body organs.
Characteristics and symptoms
Characteristics of BTPKD are at least three cysts located in the renal cortex and renal medulla between to kidneys. Detection of cysts is possible with usage of ultrasonography, but a definitive diagnosis requires DNA testing. When using ultrasonography as a way of testing, breeders cannot be sure they have a BTPKD clear line before five generations of testing. Signs of BTPKD are increased water consumption, increased urination, bad breath, sudden weight loss, blisters, shivering, lethargic and vomiting. Many affected dogs can seem to live a normal life, performing all activities regularly, without any signs of polycystic kidney disease until the final stages of the disorder. In some cases, severe symptoms appear in the time frame of 24 hours, which is a great shock to the owner. In this final stage, the veterinarian has not any options to reduce the symptoms, and has to euthanize the dog. The age of already progressed stage of PKD varies among dogs, between 2 years to 8 years, but can also occur earlier or later than that.
BTPKD is caused by a mutation in the PKD1, located at the CFA06. The disorder is inherited in an autosomal dominant manner with equal prevalence in both genders. Dog carrying one copy of mutated gene (heterozygous dog) is affected. Homozygous animals for Pkd1 mutation die embryonically.
Gharahkhani, P. (2011.): A Non-Synonymous Mutation in the Canine Pkd1 Gene Is Associated with Autosomal Dominant Polycystic Kidney Disease in Bull Terriers. PloS ONE 6 (7): e22455.