This means that the results of blood and urine tests can not diagnose separation anxiety, but they can help rule out other conditions that may be causing the dog's symptoms. (petwave.com)
Sometimes a skin patch test or allergy test may be required to confirm an eczema diagnosis by ruling out other conditions. (health.com)
If you think your child has ADHD, you might want to rule out some other conditions first. (babycenter.com)