How old is he? If he's 5 months or older you need to get him neutered soon. Once their testes become as large as that it means they're close to sexual maturity. He'll soon start spraying urine inside you house, which smells dreadful and is really difficult to clean. Get him neutered as soon as you can so he doesn't start spraying and roaming around getting into fights. You'll save yourself a fortune in vet's bills and enzyme cleaner.