Why do we pick the health testing we do?
I hope the below information is enlightening and provides some thoughts, statistics, and knowledge for fellow German Shepherd fanciers. If you would like to copy this information for your own website, please just link back to this page. I will be updating this page regularly with the new findings, so linking back allows people to see the most current information. Thanks for reading.
Spinal Health
Transitional vertebrae (TV) are widely believed to be genetic. Similarly to hips, the TV can be bilateral (different on each side) rather than uniform. The affects and prominence in the breed is increasingly worrisome. TV is also referred to as Lumbosacral Transitional Vertebra (LTV) or Lumbar-Sacral Transitional Vertebrae (LUW).
LUW is the term used by SV. However, LTV is the term used in the most common and newest German studies pertaining to German Shepherd dogs.
OFA's spine screening program is in it's infancy right now (2022). It is a testable disease in German Shepherds through OFA, but the results are not published online because the spine database is confidential. To submit a dog to OFA Spine the dog can be as young as five months old, which is when the onset of LTV can be minimally visible. The German Shepherd Schutzhund Club of Canada (GSSCC) will no longer be accepting any OFA radiographs for their breed survey requirements starting in 2023.
Symptoms
Spinal compression caused by Lumbosacral transitional vertebra (LTV) can be definitively linked to cauda equina syndrome (1).
Cauda Equina can be clearly linked to leg cramps (claudication), muscle weakness (paresis), and bowel loss (fecal incontinence).
Prevalence
Twenty percent of German Shepherd dogs had some variety of Lumbosacral transitional vertebra (LTV) according to a 2021 study.
Fifteen percent of affected dogs were asymptomatic and only identified via radiographs (LUW1)
SV provided the data of 27,597 tested dogs from the years of 2006-2015. (2)
Breeding Strategies
While many LTV1 dogs are asymptomatic, LTV is genetic in inheritance. Breeding LUW1 dogs can lead to unintended production of more severe forms of LTV (II & III) if the pairing is not carefully screened and planned. (2)
Leading vets do not recommend culling 20% of the population, but rather breeding all LUW1's to LUW0's.
Coat Pattern & Color
Remember the days when German Shepherd breeders thought that all black was dominant (A)?
Welcome to 2022. UCDavis in the United States released brand new tests identifying what creates the distribution of eumelanin in dogs. Eumelanin is the black hairs contained within the coat - such as sables, saddles, bi colors, and solid blacks.
German Shepherds have always had impossible or inconclusive results with the old A locus testing. This new research should provide valuable insight on patterns.
Additionally, UCDavis has identified genes which may produce poor phaeomelanin. German Shepherds were a focus breed in the study developing this test that should help breeders avoid cream, tan, or off-white pigment in the areas where there should be rich reds and oranges.
As a result, we pick UCDavis over Embark. Hands down, every time.
Degenerative Myelopathy
Degenerative myelopathy is considered an umbrella term for several diseases that present with the same characteristics and general age of onset. There is more than one mutation for DM.
Relevant Studies
Theorized as Hereditary
2008: 21 Affected PWC
Study Link
Although degenerative myleopathy was already known in German Shepherds, researchers studied twenty five Pembroke Welsh Corgis. When pedigrees were researched, researchers came to the conclusion that DM is hereditary.
SOD1:c.118A is Mapped
2009: 828 Dogs, All Breeds
Study Link
Data was volunteered from CHIC, University of Missouri, Harvard, and Pennsylvania. This data involved a control group where DM is rarely or not at all present in the breed.
SOD1:c.52T is Mapped
2011: 1 Bernese Mtn Dog
Study Link
A Bernese Mountain dog tested negative for SOD1:c.118A. Symptoms and spine samples were consistent with DM however. Scrutinizing DNA found a separate mutation which currently only seems present in this breed population.