Further studies of canine von Willebrand's disease
WJ Dodds
Additional characterization of von Willebrand's disease (VWD) in a family
of German shepherd dogs is presented. Genetic studies of three generations
of affected dogs indicate that about 50% of the progeny are affected if one
parent has VWD and about 60% if both parents have the defect. Some of these
progeny manifested an incomplete form of VWD, suggesting autosomal dominant
inheritance with variable expressivity. The disease become progressively
less severe with advancing age and repeated pregnancies. Ristocetin-induced
platelet aggregation was significantly reduced in VWD dogs as compared with
normal, thrombopathic, and hemophilic carrier dogs. Immunodiffusion and
electroimmunodiffusion studies with rabbit anticanine factor VII showed the
level of factor VII-related antigen to be low in VWD dogs but present in
increased amounts in hemophilic dogs. VWD affected dogs had markedly
delayed hemostatic plug formation, but their plugs appeared normal by light
and electron microscopy. Their platelet nucleotides, ATP/ADP ration, and
platelet protein content were normal. Platelet and fibrinogen survival
times with [75Se] selenomethionine were also normal, although platelets
from VWD dogs incorporated more radioactivity than did those from normal
dogs or from dogs with incomplete VWD.
Volume 45,
Issue 2,
pp. 221-230,
02/01/1975
Copyright © 1975 by The American Society of Hematology
