JERUSALEM — Israeli Prime Minister Benjamin Netanyahu on Saturday declared that he feels “very good” after he was rushed to the hospital for what doctors said likely was dehydration. Netanyahu’s office said he was hospitalized after feeling mild dizziness. It said that he had spent the previous day in the heat at the Sea of Galilee, a popular vacation spot in northern Israel, and that after a series of tests, the initial assessment was that the veteran Israeli leader was dehydrated. Later on Saturday, a smiling Netanyahu issued a video statement from the hospital, saying that he had been out in the sun on Friday without wearing a hat and without water.