The answer to 'why is my fence disease' is that your fence may be suffering from a fungal or bacterial infection, causing it to deteriorate prematurely. Common causes include exposure to moisture, poor drainage, and improper installation or maintenance. Symptoms may include discoloration, rotting, and structural weakness.
In many cases, a fence disease can be treated with antifungal or antibacterial treatments, but the underlying cause must also be addressed. This may involve improving drainage, replacing damaged sections, or adjusting the fence's positioning to prevent future issues. If the problem is severe or you're unsure of the cause, it's best to consult a professional landscaper or fencing contractor who can properly diagnose and resolve the issue.