Dog hereditary diseases

Description
von Willebrand disease (vWD) is one of the most common inherited diseases associated with blood clotting problems. Symptoms of the disease are similar to hemophilia, which is why von Willebrand disease is sometimes called pseudohemophilia.

The cause of the disease is a quantitative deficiency and / or qualitative impairment of von Willebrand factor, a multimeric glycoprotein required for platelet adhesion to collagen at sites of damage to the vascular wall. This factor also binds to coagulation factor VIII and protects it from proteolysis. Typically, vWD is hereditary, but acquired forms are also found.

The second type of disease is associated with a structural disorder of von Willebrand factor, which is the reason for the absence of VWF multimers. Affected dogs have severe bleeding disorders resulting in severe blood loss. The disease is recorded in German short-haired and wire-haired pointers (German shorthaired pointer and German drathhaar).

Type I vWD inheritance: autosomal dominant with incomplete penetrance. This means that one mutant allele may be sufficient to develop the disease, but not all dogs with one or two copies of the mutant allele will develop the disease. Carriers and homozygotes for the mutation will transmit the disease allele to their offspring.

Previously it was thought that the mutation was caused by a single nucleotide substitution 4937A> G in exon 28 of the VWF gene (Kramer et al., 2004). Relatively recently, another polymorphism was found, also correlating with the disease, located in the same haplotype - the replacement c.1657T> G (Vos-Loohuis et al, 2017). This mutation point is considered preferable, since the 4937A> G substitution was also found in the Chinese Crested, but homozygotes for this mutation did not show symptoms of the disease.

Symptoms
The most characteristic and specific symptom of vWD is bleeding from the mucous membranes of the mouth, nose, and internal organs. The manifestation of vWD can vary in severity depending on the individual characteristics of the dog. In a mild form, the disease is characterized by moderate bleeding, in more serious cases, extensive and extremely severe.

Diagnostics
Characteristic changes in the behavior and physiology of the dog.