Which indicator is primarily used to confirm an earlier diagnosis of GVD in horses?

The primary indicator used to confirm an earlier diagnosis of gastrovascular disease (GVD) in horses is radiographic signs. Radiography allows for a detailed examination of the internal structures of the horse's body, particularly the bones and any potential abnormalities in the joints or gastrointestinal tract. In cases of GVD, specific changes or signs seen on an X-ray can provide crucial information about the condition, helping to verify the initial diagnosis made through clinical signs and symptoms.

Radiographs can reveal signs of joint effusion, bone abnormalities, or other complications associated with GVD that would not be apparent through physical examination or less invasive tests. These imaging studies can thus offer a definitive assessment of the condition, leading to better treatment decisions based on visual evidence of the disease process.