The IFR Meeting of Delegates dd. 2013 in Denmark discussed the rising awareness of this evolution in canine breeds, warned that our Rottweiler breed would be no exception but although even a list of such diseases was included in the discussion, none of these were given specific attention, even not JLPP(2) as nobody was aware of the degree with which some of those diseases had already affected our breed. (3)
A brutal wake-up call came in 2016 with the establishment that maybe more than 25 % of the Rottweiler population had become a carrier of the defective gene that causes the disease JLPP !
Luckily, as the disorder is autosome recessive and the defective gene is easy to identify by a DNA-test, an adaption of our breeding regulations to the since long existing FCI-guide lines should suffice to control and maybe on the long term obliterate or at least neutralise the disorder in the Rottweiler breed.(4)
I now refer to the IFR-publication “A Laymans Walk Through Basic Canine Genetics, genetic diseases and the correlation with a reduced genetic diversity of the breed”. (5)
In this booklet we established the need for testing for genetic disorders but also asked the question if we should test for all diseases as this would clearly lead to an even further reduction of genetic diversity. The answer is therefore negative : we should not test for all disorders. (6)
However, there may be no discussion on the necessity to test for genes that are responsible for life-threatening or life-shortening diseases (for example Juvenile Laryngeal Paralysis, Subaortic Stenosis) nor about the necessity to test for genes (if DNA tests are not existent : for symptoms of those disorders) that cause serious pain or that reduce the essential functionality and quality of life (hip dysplasia, elbow dysplasia, OCD, …).
We owe it to the Rottweiler breed to be aware of this and take up our responsibility where needed and possible.
Recently, Mr. R. Tenold (former president of the Norwegian Rottweiler Club), made me aware of the growing presence in the Rottweiler’s genepool of the defective genes that cause the neurological diseases Leuco-Encephalomyelopathy (LEMP) and Neuroaxonal Dystrophy (NAD).
I will not go into detail in this first communication but I assure you that both are terrible diseases that have both been established in the Rottweiler breed for decennia.
LEMP is a recessively inherited neurodegenerative disorder that affects the white matter of the central nervous system (CNS). It is characterized by slowly worsening gait abnormalities, especially spontaneous knuckling, dragging of the paws and hypermetria of the thoracic limbs, and a characteristic pattern on magnetic resonance imaging (MRI). The affected dogs show corresponding gross lesions in the cervical spinal cord white matter that may extend to the thoracic spinal cord, as well as to the brain; peripheral nerve and muscle biopsies are unremarkable. Canine LEMP often shows a juvenile onset and is characterized by a generalized progressive ataxia. Spinal reflexes of affected dogs are mostly normal. In the progressive clinical course of the disease, affected dogs may become increasingly immobile within a few months. Like many diseases of the CNS, there is no effective treatment for LEMP.
NAD is a group of diseases that center around the neuronal axon, a specialized cellular structure that helps our nervous systems relay information across great distances. Remember: messages from the brain sometimes have to travel the entire length of your dog! Axons are the portion of the nervous system that transmit these messages quickly and reliably. When axonal disease is present, affected animals show signs that are consistent with a delay between the brain and the body: sometimes they walk with an uncoordinated gait, or don't seem to know where their limbs are relative to the ground, leading to scuffing or dragging of the paws. Here also : there is no treatment for this disorder.
Science is very much aware of the disease and its causes and it was not for nothing that DNA-tests were developed to identify the mutated gene that causes the disease.
Some online research will lead you to both scientific publications and publications that are more open for us laymen, but also to e.g. Facebook-groups about the experiences of owners of affected dogs. (7)
I am not in the possession of recent statistics but scientific publications / sources show that already some time ago not less than 9 % of the tested Rottweilers were carriers of the mutated gene ! (8)
It seems therefore that there is an already very significant presence of the disease in the Rottweiler breed and – as Mr. Tenold is researching for - in some often used blood lines !
This should not surprise us, given the reduced genetic diversity of our breed and the speed with which that other horrible disease JLPP has world wide spread.
We may not be blind, ignorant and passive again … if we can, we must act, now ! Acta Non Verba !
As both LEMP and NAD are said to inherit as an autosome recessive genetic disorder and are easy to detect by a DNA-test, we may seriously consider to test our breeding dogs for these defective genes and apply the same rules as we introduced for JLPP : to breed only with dogs that are both free of the defective gene or of which at least one is not a carrier of the gene.
At the very least, our IFR Member Clubs should make their members aware of the danger and the possibility to test !
This should not even lead to extra-sampling as some of the DNA-tests that are available to detect the presence of a mutation, are “cocktails” or combinations that can be used to identify multiple mutations at the same time.
I know for certain that for the Rottweiler such a “combination test” exists for JLPP and LEMP (e.g. offered by Laboklin but probably also by others). Also, when the laboratory is still in possession of a former DNA-sample, for example taken to test on JLPP, the additional test might be done on this same sample.
We will look further into this and if more info and/or recent statistics are available, we will then report to all Member Clubs again. But please, do not ignore the warning … make it known to your members.
On behalf of the IFR-Board,
With friendly greetings,
D. Vandecasteele.
(1) Cfr. the list of the 776 Mendelian genetic disorders that were identified in canine breeds, published by the University of Sydney : https://www.omia.org/results/?search_type=advanced&gb_species_id=9615
(2) JLPP = Juvenile Laryngeal Paralysis.
(3) Genetic diseases that were identified in the Rottweiler’s breed pool : Genetic diseases that have been established in the Rottweiler’s genepool : Aortic Stenosis (Sub-), Cataract, Chronic sesamoiditis, Congenital deafness, Congestive/ dilatative cardiomyopathy, Demodicosis, Dilated cardiomyopathy (DCM), Duchenne muscular dystrofy (DMD), Elbow dysplasia, Entropion – Ectropion, Epilepsy, Follicular parakeratosis, Hemofilia B, Hip dysplasia, Histiocytoma (canine cutaneous histiocytoma), Hyperadrenocorticism, Hypertrofic osteodystrofphy, Hypoadrenocorticism, JLPP – Juvenile Laryngeal Paralysis, Leonberger Polyneuropathy, Leukoencephalomyelopathy, Lymphedema, Masticatory myositis, Mitral Valve Insufficiency, Mucopolysaccharidosis, Narcolepsiy, Neuroaxonal dystrophy, Osteochondritiis dissecans (OCD), Osteosarcoma, Patella Luxation, Progressive retina atrofia, Retina Dysplasia, Uveodermatologic syndrome, Vitiligo, Von Willebrands disease, Wobbler syndrome, X-chromosome related muscle dystrophy.,
(4) Results from DNA tests for inherited diseases should be used to avoid breeding diseased dogs, not necessarily to eradicate the disease. Dogs shown to be carriers (heterozygote) for a recessive inherited disease should only be bred to a dog that is proven not to carry the allele for the same disease.
(5) Online available in English and Spanish on www.ifrottweilerfriends.org . For a hardcopy of the booklet, contact your IFR-Delegate.
(6) Cfr. also the FCI International Breeding Strategies : ““Screening should only be recommended for diseases and breeds where the disease has major impact on the dogs’ functional health”.
(7) Examples:
https://pubmed.ncbi.nlm.nih.gov/29643404
https://pubmed.ncbi.nlm.nih.gov/29945969
https://vetmed.umn.edu/research/labs/canine-genetics-lab/genetic-research/leonberger-leukoencephalomyelopathy
https://embarkvet.com/products/dog-health/health-conditions/neuroaxonal-dystrophy-nad
FB group : “Lemp Rottweilers Australia”
(8) Studies at the Institute of Genetics at the University of Bern, showed some time ago already, that of 233 tested Rottweilers 9 % was carrier of the LEMP-gene and of 288 Rottweilers more than 7 % of the NAD-gene.
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