Clinical outcome after diagnosis of hemophilia A in dogs.

Objective: To evaluate the clinical course of dogs with hemophilia A (factor VIII deficiency) and to determine whether factor VIII coagulant activity (FVIII:C) was associated with severity of clinical signs and outcome.

Design: Survey study.

Sample: Respondent information for 39 client-owned dogs with FVIII deficiency.

Procedures: Information was obtained via a survey distributed to the American College of Veterinary Internal Medicine and American College of Veterinary Emergency and Critical Care email list serves and to the Veterinary Information Network community to identify dogs with hemophilia A (FVIII:C ≤ 20%). Severity of FVIII deficiency was classified as mild (FVIII:C, 6% to 20%), moderate (FVIII:C, 2% to 5%), or severe (FVIII:C, < 2%).

Results: Data for 39 dogs (38 males and 1 female) were compiled. Mixed-breed dogs, German Shepherd Dogs, and Labrador Retrievers were most commonly affected. In most (34/39) dogs, disease was diagnosed at < 1 year of age. Bleeding associated with teething, minor trauma, vaccination, and elective surgical procedures most commonly prompted FVIII:C testing. Affected dogs had similar signs of spontaneous hemorrhage regardless of the magnitude of FVIII deficiency. Four dogs were euthanized without treatment at the time of diagnosis. Thirty dogs received ≥ 1 blood transfusion; FVIII:C did not appear to influence transfusion requirements.

Conclusions And Clinical Relevance: Results indicated that dogs with hemophilia A have variations in clinical course of the disease and may have a good long-term prognosis. Residual FVIII:C may not be useful for predicting severity of clinical signs, transfusion needs, or long-term prognosis.