2010 ASCA Kidney Disease Survey

by C.A. Sharp  

May 2013

 

 The Health and Genetics Committee of the Australian Shepherd Club of America conducted a brief kidney disease survey in response to member concerns about this type of disease in the breed.  The data collection concluded February 3, 2010.  Notice of the survey providing a URL link to the survey form was sent to 5595 valid e-mail addresses for ASCA members.  Additional promotion was done via Aussie-L.  The survey was open to ASCA members only.  The survey received 1452 responses, representing 30.0% of the initial contacts (there is no way to determine how many members may have come to the survey through the Aussie-L promotion.  This is a significant rate of return and established a record for health surveys in our breed, both in terms of rate of return and total numbers of responses.  The brief nature of the survey likely contributed to the large response, but even so it received more than double the 612 responses to ASHGI’s 2009-10 Comprehensive Breed Health Survey which was ongoing at the time.

Participating owners were asked how many Aussies they had been primary owner of.  Half reported one to three and 24% indicated they had had more than eight, a reflection of the dedication of Aussie owners to their breed.

7% reported that they had had a dog with kidney disease.  A survey of this kind is apt to attract people who have experienced the disease in their dogs and almost all respondents had owned multiple Aussies, so this cannot be taken as an indication of frequency of kidney disease in the breed.  Even so, a large enough number of owners were impacted to indicate this type of disease deserves attention.

Respondents reported that most (71%) dogs were diagnosed were older than three years, though 21% were diagnosed under two years.  These results are consistent with the nature of renal disease.  Most cases become clinical later in life but the significant minority of younger dogs diagnosed is consistent with some level of serious congenital disease.  Without being able to correlate specific diagnoses with age sets we cannot determine with certainty from this survey how many of the youngest cohort had congenital disease vs. disease due to other causes, though most other causes (secondary disease, dysfunction due to trauma or toxic exposure, age-related deterioration) are more frequent in dogs 3 years of age and up.

Virtually all (99%) respondents indicated their dogs were diagnosed by a veterinarian, with 11% of them diagnosed by specialists so the majority of initial diagnoses were made by small animal practitioners, though possibly later confirmed by specialists later.  None of the dogs were breeder-diagnosed, which isn’t surprising with a disease that requires multiple diagnostic tests.

The disease 

Respondents reported that they were prompted to take their dogs to the vet because the dogs were exhibiting (in order of frequency) frequent or inappropriate urination or loss of bladder control, excessive water consumption, lethargy, anorexia, vomiting, weight loss, dilute urine, and/or any of several other signs which were reported by 3 or fewer respondents. No single disease sign was noted in a majority of the cases, however significant minorities experienced problems with urine excretion and/or drinking excessive amounts of water.  Weight loss and lack of appetite can be related and together they also represented a significant minority of the dogs with kidney disease.  These signs are common in advanced renal disease.

29% of respondents reported that their dogs had Renal Dysplasia (RD).  77 responses, 20% chronic renal disease or renal failure, and 9% secondary to other (non-renal) diseases, with the rest unspecified, unknown, or diseases reported in very low percentages.  The take-away here is that RD, while not common in the breed, is the most frequently reported disease of the kidneys.  RD is inherited.  Blood work and urinalysis were the most frequently used diagnostic tests, though nearly a third also received ultrasound.  Biopsy or submission of a necropsy sample to a pathologist was also performed in 12% of cases.

Blood work and urine analysis are basic tests done to determine kidney status.  Ultrasound enables the veterinarian to view kidney shape and structure.   Few were biopsied, which is not surprising as this highly invasive procedure can be risky to perform on dogs whose health is already seriously compromised.  Necropsy tends to be underutilized as a diagnostic tool because of the expense, the fact the dog has already died, and – perhaps most pertinent – the decision to necropsy can be very difficult to make in a time of emotional distress.   X-rays were used in a few cases, most likely used to determine whether kidney stones were present.  Aussies are subject to urate stones, another inherited kidney disorder and one for which there is a DNA test.

A small portion of respondents reported their dogs died as infants or juveniles.  Since kidney disease in the young is often congenital and severe, these dogs plus some portion of those in the 3-6 year category probably represent many of the 28.7% dogs in those age groups reported under age at diagnosis.   Survivorship among serious renal disease patients who are very young is poor.

Renal disease is common in elderly dogs, so the finding that 19% of dogs 13 and older died of renal failure is not surprising.  Of greater concern are the dogs who died from 7 to12 years (32.3%).  To the extent that these dogs died of a primary renal disease, which cannot be determined, we may have a more common killer of mature adult dogs than we realized.

Treatment

Slightly more than a third of the dogs received fluid therapy which becomes necessary should the disease cause serious dehydration.  21% received medication.  Almost three quarters altered their dogs’ diets, frequently a necessary part of maintaining a dog with any chronic renal disease.  Two thirds (64.7%) were put on prepared renal care diets.  Various other dietary changes were employed with home prepared meals or supplementation being used for significant minorities of these dogs.

About a quarter of the kidney disease dogs apparently did not receive medical or dietary treatment due to their disease.  Without detailed data it is not possible to know why, but some dogs may have been terminal at time of diagnosis.

Family Connections

One of the questions asked respondents whether their dog had relatives affected with kidney disease.  9% indicated their dogs had affected relatives.  Given that kidney issues are not seen as a primary breed health concern nor do people realize that some kidney disease (RD and urate stones) are inherited this number may be understated.  In addition, some individuals will not share negative health information so respondents may not have been aware of affected relatives.  More may have affected kin than the responses indicate.  This is especially so in view of the fact that 28% of the affected dogs were diagnosed with renal dysplasia, which is hereditary.

Conclusions

Renal disease was reported by 7% of dogs reported in this survey with just under a third of them diagnosed with RD, a potentially fatal renal disease.  Mode of inheritance for RD is not determined, but we can safely assume there are healthy dogs in the population who carry genes that contribute to the disease.  In addition, clinical disease may not be noted until a dog has already been bred.  Dogs with RD may not receive definitive diagnosis as this requires a biopsy or necropsy.  The survey results indicate that a minority of dogs with renal disease had one of these procedures done, so it is reasonable to assume that there is some portion of dogs with RD that were not identified as such.

Concerns about RD motivated the ASCA committee to mount this survey.  The results indicate that the percentage of dogs in the entire survey (1452) with RD could range from a minimum of 1.5% to as high as 4.2%, with the actual number probably lying somewhere between the two.  Even at the minimum level this is an important finding as a much larger percentage of the breed will be carrying genes for RD.

The survey results clearly indicate that our breed community does need to pay attention to RD.  Aussie owners and breeders need to educate themselves about the signs of the disease and the importance of proper diagnosis.  ASHGI recommends that affected dogs be withdrawn from breeding.  If semen has been stored from affected males, it should be discarded.  Healthy relatives should be bred only to mates with no family history of this sometimes lethal disease.  ASHGI and this author have long promoted the open sharing of health information; if breeders don’t know where the problems are they cannot make informed breeding decisions.  One way of sharing this information is through use of the IDASH Open Health Database.

Finally, increased awareness and education of Aussie owners about renal disease in general is necessary and something that clubs and breeders should undertake.  The earlier disease is identified, the longer the affected dog’s quality of life can be maintained through alterations in diet, medication or other treatments.