German shepherds as we know them today is a relatively new breed. This breed is the result of a vision of a man named Max von Stepanitz. His vision was to create a superior German herding work dog. He pictured an athletic, intelligent dog that was fast, capable and had a good sense of smell. In 1899 during a show Von Stepanitz came across a dog named Hektor Linksrhein, which was just like the one he had imagined. Von Stepanitz bought the dog immediately and changed its name to Horand von Grafrath. Soon after that he founded The German Shepherd Association to establish a breed from Horand’s descendants. Rapid industrialization reduced the need for shepherd dogs, so the future of this breed was focused on police and military work.
German shepherds are very intelligent and devoted to their owners which makes them wonderful pets and family protectors. Just as they protect their family, they also need protection and care themselves from their family. In addition to nutritional care and their other needs it is possible to contribute to their health through the use of DNA tests for inherited diseases.
Pituitary dwarfism (CPHD) in German shepherds
Pituitary dwarfism in German shepherds is a well known defect. Dwarfs are born in purebred populations all over the world with a mutated allele frequency of 9.4%. Pituitary dwarfism or congenital growth hormone deficiency manifests itself through marked growth retardation, retention of secondary hairs combined with a concurrent lack of primary hairs, and bilateral symmetrical alopecia. CPHD is a recessive disorder characterized by an underdeveloped pituitary gland and a combined deficiency of growth hormones, thyroid stimulating hormones, prolactin, and gonadotropins. With the discovery of the causing mutation and the development of a DNA test for CPHD, dwarfs can be avoided in breeding.
Hyperuricosuria (HUU) in German shepherds
Hyperuricosuria is an excessive excretion of uric acid in the urine, a condition that predisposes dogs to urate urolithiasis. Through the use of genetic tests, a mutant allele frequency of 2.6% was established. The prevalence of HUU can be lowered over time by decreasing the frequency of the mutant allele in breeding populations, with help of a DNA test for the condition.
Von Willebrand’s diasease in German shepherds
Von Willebrand’s disease type 1 (VWDI) is an inherited bleeding disorder common in German shepherd dogs. In WWDI the bleeding occurs due to the reduced amount of von Willebrand factor (vWF) which plays an important role as a clotting factor. Type 1 VWD is inherited in a recessive fashion in German shepherds. A genetic test for von Willebrand’s disease can help in the prevention of this serious bleeding disorder and also in discovering carriers.
Other DNA tests for genetic diseases
Degenerative myelopathy, a serious disease we have written about before, is common in German shepherds. Other genetic diseases that can occur in this breed are malignant hyperthermia and multidrug resistance, all of which have DNA tests available.
Karmi, N., Safra, N., Young, A., and Bannasch, D.L. (2010). Validation of a urine test and characterization of the putative genetic mutation for hyperuricosuria in Bulldogs and Black Russian Terriers. American Journal of Veterinary Research 71, 909–914.
Venta, P.J., Li, J., Yuzbasiyan-Gurkan, V., Brewer, G.J., and Schall, W.D. (2000). Mutation causing von Willebrand’s disease in Scottish Terriers. J. Vet. Intern. Med. 14, 10–19.
Voorbij, A.M.W.Y., van Steenbeek, F.G., Vos-Loohuis, M., Martens, E.E.C.P., Hanson-Nilsson, J.M., van Oost, B.A., Kooistra, H.S., and Leegwater, P.A. (2011). A contracted DNA repeat in LHX3 intron 5 is associated with aberrant splicing and pituitary dwarfism in German shepherd dogs. PLoS ONE 6, e27940.