The Hornets had one just one out of eleven since Everton made two approaches to speak to Silva – which were rejected – having won six of their previous 12 games.
The statement said that the club and manager had parted company, and although not naming Everton, the statement went on to say that an unwarranted approach for Silva had led to the downturn in results.
It said, “This has been a difficult decision and one not taken lightly. The Club is convinced the appointment of Silva was the right one and had it not been for the unwarranted approach by a Premier League rival for his services we would have continued to prosper under his leadership.
“The catalyst for this decision is that unwarranted approach, something which the Board believes has seen a significant deterioration in both focus and results to the point where the long-term future of Watford FC has been jeopardised.”
Everton appointed Sam Allardyce after both approaches for Silva were rebuffed and now sit two points above Watford in ninth. Watford were six points ahead of the Blues when the approaches were made.