Máš to vytrhnuté z kontextu a hlavne ako insert súvisí s update?
Ak chceš vkladať údaje pomocou parametrov potom by to mohlo vyzerať asi nejak takto:

static void AddDog(int weight, string name, string breed)
{
    using (SqlConnection con = new SqlConnection(
	ConsoleApplication1.Properties.Settings.Default.masterConnectionString))
    {
	con.Open();
	try
	{
	    using (SqlCommand command = new SqlCommand(
		"INSERT INTO Dogs1 VALUES(@Weight, @Name, @Breed)", con))
	    {
		command.Parameters.Add(new SqlParameter("Weight", weight));
		command.Parameters.Add(new SqlParameter("Name", name));
		command.Parameters.Add(new SqlParameter("Breed", breed));
		command.ExecuteNonQuery();
	    }
	}
	catch
	{
	    Console.WriteLine("Count not insert.");
	}
    }
}