• Rachel Cianciolo, Asst. Professor and Mary Nabity, Assistant Professor,
Co-Directors of the International Veterinary Renal Pathology Service
|Bullmastiff Health & Research|
The Health and Research Committee of the American Bullmastiff Association is working with the American Kennel Club Canine Health Foundation to obtain information regarding the term “Renal Dysplasia”. As you may know, there has been a lot of discussion regarding this condition. The goal of this committee is to provide accurate and scientific information as opposed to possible misinformation.
First, we must define renal dysplasia. There is genetic renal dysplasia (usually noted as juvenile nephropathy) and is usually identified in young/juvenile dogs. Tissue biopsy is required to determine the cause of the disease. For clarity, this is what is considered genetic induced renal dysplasia as opposed to renal dysplasia caused by other factors. The kidneys are a complex organ. Its primary function is to filter out all impurities. One must remember that the kidneys can be affected by connecting structures such as the ureter and bladder. Infections (such as leptospirosis, lyme disease, pyelonephritis), exposure to toxins, inoculations, auto-immune disease and neoplasms can all have an affect in the urinary tract which can migrate, interfere with or originate in the kidney. These conditions can affect the kidney causing “renal dysplasia” but it is not the genetic type.
For clarification, the renal dysplasia discussed herein is that of a genetic nature. To date, there has been a very small sample in Bullmastiffs as opposed to other breeds. Whereas over 100 Labrador Retrievers have been examined, only a total of 5 Bullmastiffs have been examined according to the International Veterinary Renal Pathology Service.
The difficulty is that lesions consistent with renal dysplasia have not been positively identified as to a genetic/heritable disease. Because canine kidneys continue to develop after birth, it is entirely possible that these dogs were exposed to a toxin or virus in utero or shortly after birth. These types of insults can stop growth of the kidneys and result in kidneys that look very familiar to genetically induced renal dysplasia.
What are the symptoms of genetic renal dysplasia? The initial signs are typically increased thirst, drinking, and urination. The urine is usually very dilute. As the disease progresses, signs such as decreased appetite and activity, poor body condition, vomiting and bad breath can occur. Blood values would indicate an increased serum creatinine and there may also blood and protein in the urine.
How do we diagnose genetic renal dysplasia? As stated above, tissue biopsy is the only reliable test at this time. Tests to rule out other factors must also be explored.
Is this an inherited disease? At this time, there is no scientific evidence that has reported a specific gene that causes this. This is not to say it does not exist. There have been other breeds that have been identified but whether or not it is the same gene is unknown.
What is the mode of inheritance for genetic renal dysplasia? There is no known genetic basis for bullmastiff renal dysplasia and no peer-reviewed scientific literature that has reported the gene. Therefore, mode of inheritance and similarity or difference to other breeds cannot be determined.
Can I do anything to prevent this? Genetic induced renal dysplasia “usually” affects young dogs. However, an older dog may develop some form of kidney disease later in life. Yearly blood panels (CBC, BUN, Creatinine levels) can indicate if there is a decline in kidney function. Diet, medication and vigilance can give your dog a good quality of life.
Is there a reliable test? Currently, no. Until we find a way it is inherited and the research to identify it we need to be aware and take all factors into consideration, particularly when it comes to breeding. There has been some talk regarding the DogGenes test but it has not been appropriately validated. Some of the methods and materials used are questionable.
For further information see the following:
The take away from all this is that more research is needed. If you have had the misfortune of having a dog succumb to genetic induced renal dysplasia, a tissue sample is vital to help determine if there is indeed any genetic correspondence. Tissue samples should be sent to the Broad Institute.
Submission forms can be found at: http://www.broadinstitute.org/dogsamples