ภาวะพร่องแฟกเตอร์ VII

Overview

Factor VII deficiency is an inherited clotting disorder affecting the extrinsic coagulation pathway. It is typically mild, and many affected dogs never bleed spontaneously.

Causes

A recessive mutation in the F7 gene reduces functional factor VII. Beagles are a classic breed, with cases in several others.

Signs

Many dogs are asymptomatic. When bleeding occurs it tends to follow surgery, injury or dental procedures, sometimes with bruising or prolonged bleeding.

Diagnosis

A prolonged prothrombin time with normal other clotting tests, specific factor VII assay, and a DNA test for the F7 variant confirm the diagnosis.

Treatment & Management

Significant bleeding is managed with plasma transfusion. Most affected dogs need only awareness and precautions before surgery.

Prevention

DNA testing of breeding dogs in affected breeds and pre-surgical screening prevent unexpected bleeding and reduce the trait.